Israel Hands

Best tool to shorten stainless bolts?

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I'm rebedding jib tracks and have a number of 6mm stainless bolts that I will need to cut down (all to the same length). I have a dremel tool I guess I could use, but this seems like a situation that justifies purchasing an angle grinder (?)  I want to pre-cut the bolts, so need the threads to function okay after the cut.

The Beneteau factory in France cut these flush with the nuts in the original installation, then glued padded vinyl headliner overtop of them.  I've gone back with glued-in furring strips and vinyl panels, so that now I have some working room and can afford to have a bit of extra length on the bolts (don't have to cut them off exactly flush).

What is the most expeditious way of doing this?  

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I've had good success using an oscillating multi-tool with a carbide blade for cutting stainless bolts and nuts and other shit around the boat.

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I can report angle grinder makes an unholy mess and the red hot stubs that fall on your scalp are quite warm. Oscillating tool works and is cleanER but takes much longer if you’re doing many. If they are not coming out any time soon perhaps big bolt cutters would work and be way faster? 

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Since you mention wanting to make sure the threads are good after the cut, you probably know to put nuts on the bolts before you cut them. Removing the nuts after the cutting clears/cleans the threads. 

 

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OP is “pre-cutting” the bolts, as per his post. If they are less than 1/2 inch, use a hacksaw. Even if they’re bigger, it Will just take patience. Cleaner and less heat. Otherwise, grinder with cutoff wheel

As the man said above, you’ve got them out. Replacing with correct length is probably cheaper than buying tools, but then any excuse to buy tools is good

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Helpful hint, run a nut down prior to cutting. After cut slightly bevel the cut and unthread the nut and it will chase the thread and clean it up as it comes off. 

 

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Good information - thanks folks.

The reason I need to cut them down is that I ordered replacements from Beneteau and received the overly-long bolts.

I was hoping for a solution to pre-cut them before installing - to avoid sparks on my scalp and all over the cabin. Maybe the Dremel is slow but the best way to go....

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55 minutes ago, InfiniteElement said:

I can report angle grinder makes an unholy mess and the red hot stubs that fall on your scalp are quite warm. Oscillating tool works and is cleanER but takes much longer if you’re doing many. If they are not coming out any time soon perhaps big bolt cutters would work and be way faster? 

Missed that you are pre-cutting. Disregard my non-relevant advice. 

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As long as you thead a nut or (if doing many) a threading die onto them before cutting, you can use almost anything.

The threads on the nut will eventually deform if you use the same one for this over and over.

I myself would use a right-angle die grinder with a cutoff wheel.  They are larger than a dremel, smaller than an angle grinder, and more useful than either.  I have the battery powered one from Milwaukee and like it better than my old air powered one.

Otherwise you can use bolt cutters (they will leave a rougher end) or a hacksaw, or a metal cutting bandsaw, etc.

McMaster-Carr will happily sell you bolts in any combination of length, material, thread form, head, and drive, which is helpful in some situations though sometimes there's no way to avoid cutting to length at installation.

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Beware the nut chasing trick - it typically leaves a small but lethal burr ...

If I couldn't buy the right length, I'd make a plate the right thickness and tap several holes, thread bolts into it, cut off, apply to belt sander, remove bolts, chamfer/deburr each individually on belt sander, passivate.

Using carbon steel tools on SS bolts will produce rust from tramp iron ...

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39 minutes ago, Israel Hands said:

Good information - thanks folks.

The reason I need to cut them down is that I ordered replacements from Beneteau and received the overly-long bolts.

I was hoping for a solution to pre-cut them before installing - to avoid sparks on my scalp and all over the cabin. Maybe the Dremel is slow but the best way to go....

Dude, just buy the right length and consider the Beneteau bolts the cost of education. 

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If you use a hacksaw, use some cutting fluid. It will help all parties involved. After the nut is off you can clean up any burrs with a file. 
 

but the real answer is buying the right length. 

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Because McMaster doesn't deliver instantaneously, I have a small portable vice, an angle grinder and a tap/die set that I can take to the boat. I grind outside the boat as those little bits of steel WILL rust. and you'll have rusty metal dust all over the boat.  It's even nicer to your neighbors if you go to the parking lot, or, in my marina's case, to the workbench.

A die set will chase the threads.

My grinder is the portable Ryobi, which is my "rig-down, cut it away" tool.

Hint on that, turnbuckles are bronze. Cuts easy.

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Best to not assume the deck is the same thickness over the length of the track you are installing if you are pre-cutting fasteners

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I've shortened a thousand bolts. For weight control and scalp bleeding prevention. I use acorn nuts wherever people might be. But grinding the bolt end to a round and just long enough end is good too.

Must be done outside of the boat, ashore, to avoid a million rust spots from the shards. Angle grinder with thin cutoff wheel is best.  I thread a die on the bolt, backwards, and clamp in a vice. A nut works almost as good.  Cut. Then grind flat on a bench grinder with fine wheel. Then grind a chamfer. Then unthread the die. Perfect.

Buying the exact right bolt is better. But takes some time and money.

 

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Stupid question:

What size bolt exactly is needed for the application?

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To do one or two, and angle grinder or dremel or hacksaw works. To do 5 or 50, buy the right length. If you really have to cut them, band saw. If you have to cut 100+, build a fixture for the mill and mill them. 

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if they're too long, install them, nut them, and use a pair of vice grips to snap them off. way faster than precutting.

 

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4 minutes ago, ryley said:

if they're too long, install them, nut them, and use a pair of vice grips to snap them off. way faster than precutting.

 

Jib tracks, something like 5/16" or 7-8MM.  Too much to snap them off...

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28 minutes ago, El Borracho said:

I've shortened a thousand bolts. For weight control and scalp bleeding prevention. I use acorn nuts wherever people might be. But grinding the bolt end to a round and just long enough end is good too.

Must be done outside of the boat, ashore, to avoid a million rust spots from the shards. Angle grinder with thin cutoff wheel is best.  I thread a die on the bolt, backwards, and clamp in a vice. A nut works almost as good.  Cut. Then grind flat on a bench grinder with fine wheel. Then grind a chamfer. Then unthread the die. Perfect.

Buying the exact right bolt is better. But takes some time and money.

 

I'm going with sex nuts, even better than acorns, even more a bitch to get the right length.

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6 minutes ago, Raz'r said:

Jib tracks, something like 5/16" or 7-8MM.  Too much to snap them off...

OP says they're 6mm, which is 1/4". they snap just fine if they're long enough.

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2 hours ago, Israel Hands said:

ok, yes it sounds like buying right length is the way to go.

Not if you are a massochist 

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I've done it lots where stock length fasteners are not quite right.

To recap the salient points above;

If you need lots of them, pay the $2 and buy new ones of the correct length.

Otherwise, put a nut on, cut to length with a cutoff wheel.

Take the nut off to create the burr.

File the end to create a small taper - I prefer a bench sander for this but a file works.

Install it with a polished acorn nut if it shows or if a scalp will ever get anywhere near it.

 

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5 minutes ago, SloopJonB said:

I've done it lots where stock length fasteners are not quite right.

To recap the salient points above;

If you need lots of them, pay the $2 and buy new ones of the correct length.

Otherwise, put a nut on, cut to length with a cutoff wheel.

Take the nut off to create the burr.

File the end to create a small taper - I prefer a bench sander for this but a file works.

Install it with a polished acorn nut if it shows or if a scalp will ever get anywhere near it.

 

There are about 20. I am going to take 2 more out of the track and see how much variation there is. If they are all close in length, I'm buying new ones. If there is variation, I'll do it as above.

Thanks

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Sex nuts with a fender washer is the cleanest install possible, short of welding the track to the deck. Length is critical as as you only have about 3/16 of variance possible between bottoming out & not enuff thread engagement. Get everything cleaned up & dry fit (with tight fasteners) before final install goopage.

Cut bolts OFF the boat, chamfer the end very slightly, run a die over it. A nut does not do a great job - and if you gall a sex nut in the middle of the final install many bad words will escape.

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Dremel with a emery cutoff wheel is surprisingly slow.  A hacksaw with a good blade and cutting fluid works best for me.  Faster than the dremel. Not nearly as much dust as an angle grinder.  Use a file or angle grinder to touch up the end to cut off the nib where the hacksaw cut broke through.

Locknuts with the bolt cut perfectly flush are lower in profile than acorn nuts and the bottom is more round and less pointy too.  Sex nuts are even better, but you need to enlarge the hole so the barrel can fit down it.

To get bolts cut accurately, I'll mark them after a test fit by using a small hacksaw blade to cut a tiny notch, just enough to see.  I haven't found any ink that survives removal.  Then I take them out and put on two nuts tightened against each other, so they don't turn, to make a fence to guide the hacksaw cut at the right spot.  Use a file and then sand paper to get the end looking nice.

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If cutting by hacksaw, threading on a nut will give you a more stable hold in a vise. If using a bandsaw, you are more likely to get a square end using a nut. A bench grinder or sander can clean up or chamfer the cut end. Another method is to chuck the bolt head in a hand drill and run the cut end up against your abrasive of choice. I use a metal bandsaw and a 1” belt sander. Short bolts do get hot.

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I have cut down thousands of bolts over the years but typically unc. I use, believe it or not a Harbor Freight bolt cutter but it is nothing like what you have in mind, it is a giant version of the ones on the end of a cheap crimp tool, it will shear up to 5/16" ss bolts and leave the thread ready to spin a nut on. It is actually a knock off of a vintage Stanley Jobmaster # 84-205 bolt cutter, they don't make them anymore and neither does HF but occasionally they come up used on ebay, in fact there is one on there right now. Every boat owner should have one. I modified mine to mount on the wall. I have not seen a metric version in the US.

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For something like 6mm, I've had good luck using the bolt cutters on electrical strippers/ cutters. I think a lot of peoe don't realize these come with bolt cutters. Works great. Something like these, you probably already have some. https://www.lowes.com/pd/Southwire-6-in-1-Multipurpose-Stripper/50081486?cm_mmc=shp-_-c-_-prd-_-elc-_-google-_-lia-_-106-_-electricaltoolsandtesters-_-50081486-_-0&placeholder=null&&ds_a_cid=112741100&gclid=CjwKCAiAwrf-BRA9EiwAUWwKXmTAyKHj-l4pDfDFtfEwrSjI1Pqi7cAUDIOCa8umvNvMTZ5swDOVGBoC7JwQAvD_BwE&gclsrc=aw.ds

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Would those be the holes that say "cut copper only"?

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14 hours ago, Raz'r said:

Because McMaster doesn't deliver instantaneously, ...

Depends on where you are maybe?  I think I've gotten almost every order the next day, using regular shipping.  I'm not far away (Long Island) so it is a short trip from NJ, but still those guys have been great every time.  Really a fantastic resource.

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Best tool to shorten stainless bolts?

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13 hours ago, El Borracho said:

I've shortened a thousand bolts. For weight control and scalp bleeding prevention. I use acorn nuts wherever people might be. But grinding the bolt end to a round and just long enough end is good too.

Must be done outside of the boat, ashore, to avoid a million rust spots from the shards. Angle grinder with thin cutoff wheel is best.  I thread a die on the bolt, backwards, and clamp in a vice. A nut works almost as good.  Cut. Then grind flat on a bench grinder with fine wheel. Then grind a chamfer. Then unthread the die. Perfect.

Buying the exact right bolt is better. But takes some time and money.

 

+1   Not done thousands but quite a few for installing deck and cabin hardware. The sizes you have never are the ones you need.....

Angle grinder with cut-off wheel followed by a cleanup (flatten and chamfer) with a grinding wheel.   Once you get the hang of it no need to put a nut on first.

Then polish the heads.

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16 hours ago, 2airishuman said:

...

I myself would use a right-angle die grinder with a cutoff wheel.  They are larger than a dremel, smaller than an angle grinder, and more useful than either.  I have the battery powered one from Milwaukee and like it better than my old air powered one.

...

A battery powered die grinder... not an air tool.... Thanks for letting me know I need another tool!

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Ill second the Milwaukee - amazing tool.  Wish I would have bought it earlier.  I have found so many uses for it on and off the boat.  The roloc abrasive and scotchbrite discs are awesome.  I pick it up before the air die grinder since its so easy to grab and go - no air hose.    

2485-Accessory-Matrix.png?mw=520&mh=520&hash=9BE64229862591601BDF4BED0ABD71AFD565D481

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Is this not the reason you need to buy a metal lathe?

I usually use a hacksaw and then file a chamfer on the end to clean up the threads. A cutoff wheel is quick but makes a mess.

Sometimes it's worth making a split nut for work holding. Cut a slot in one side of a nut, thread the bolt into it and then grab the nut with a vice or vicegrips or whatever.

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1 hour ago, yoyo said:

Ill second the Milwaukee - amazing tool.  Wish I would have bought it earlier.  I have found so many uses for it on and off the boat.  The roloc abrasive and scotchbrite discs are awesome.  I pick it up before the air die grinder since its so easy to grab and go - no air hose.    

2485-Accessory-Matrix.png?mw=520&mh=520&hash=9BE64229862591601BDF4BED0ABD71AFD565D481

Even better is the Bosch articulating  chuck cordless right angle drill 

the articulating chuck , 90 thru 180 in steps , allows the tool to be used like a pencil . Very compact 

this is the most useful tool in my bag for work in confined spaces 

 

D160793D-DB87-4E5A-B5B1-8E4F44F7EEC4.png

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51 minutes ago, weightless said:

Is this not the reason you need to buy a metal lathe?

I usually use a hacksaw

"Honey, I've got $10 worth of bolts here I need to shorten so I have to buy a $2500 lathe"

The truly strange part is I can almost hear myself saying it.:lol:

If you prefer to hacksaw S/S rather than use a cutoff wheel then you fit the definition of masochist.

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I remember some guy who built a Colvin Gazelle with a metal shop aboard. And the great Jim Brown cartoon: "You weldum aluminum?"

Because tools.

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41 minutes ago, SloopJonB said:

If you prefer to hacksaw S/S rather than use a cutoff wheel then you fit the definition of masochist.

:) I didn't say I prefer a hacksaw. I just usually end up using one. But sometimes it seems like this is true:

image.png.9985d7346fd2f294b352bfa867298f5c.png

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Negative, Cut copper only is referring to the wire cutting blade, not the bolt shears. I use them on SS all the time, however, I did my metric conversion wrong. Most of these stop at #10, so finding one for 1/4" (6mm) is probably going to be tough. Like a few others have said, why not just buy the right size?

14 hours ago, SloopJonB said:

Would those be the holes that say "cut copper only"?

 

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20 minutes ago, JoeBleaux said:

Like a few others have said, why not just buy the right size?

Because that right size is not available. 1/2" increments at best.  And the hundreds of dollars of surplus screws in storage here are just begging to be cut down and re-used.

1 minute ago, Grande Mastere Dreade said:

wouldn't using an angle grinder with a cutoff wheel heat the bolts so much that they lose their hardness / integrity ?  

I don't think that happens. The angle grinder is quick and the screw doesn't seem to very hot. Doubt heat and slow cool weakens s/s anyway. 

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5 minutes ago, El Borracho said:

 

I don't think that happens. The angle grinder is quick and the screw doesn't seem to very hot. Doubt heat and slow cool weakens s/s anyway. 

ever touch a screw that's just been cut?   it'll fucking leave 2nd degree burns..   especially if the bolts are #12's or bigger and take longer to cut..

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1 minute ago, Grande Mastere Dreade said:

ever touch a screw that's just been cut?   it'll fucking leave 2nd degree burns..   especially if the bolts are #12's or bigger and take longer to cut..

Yup. Do it all the time just to remind myself how forgetful I am. But only the little last thin bit gets red hot for a second when cutting. I do lotsa welding of 316 s/s. That heat doesn't seem to change it in any big way. Burns the fingers pretty good too.

Red hot steel is around 600 C and up, tempering and annealing temps are twice that. The body of the cut bolt doesn't get anywhere near red hot. Wikipedia says 2nd degree skin burn starts at only 55 C.

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This looks pretty good. Can't find anyone in the US with it in stock though. Wouldn't be too hard to make something similar where you could do multiple at once with a vice. https://www.aircraftspruce.eu/sbs-1--sae--screw-cutter.htm

I glanced at Mcmaster, they have 1/4-20 in .25" increments, but if you just want to use what you have that doesn't matter. 

21 minutes ago, El Borracho said:

Because that right size is not available. 1/2" increments at best.  And the hundreds of dollars of surplus screws in storage here are just begging to be cut down and re-used.

 

 

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28 minutes ago, Grande Mastere Dreade said:

wouldn't using an angle grinder with a cutoff wheel heat the bolts so much that they lose their hardness / integrity ?  

I wouldn't expect so.  Annealing temps for 304 & 316 are frigging hot.

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19 hours ago, silent bob said:

Yep, that is exactly the tool I reference up thread. I bought a used one for at  work and my son also bought one, both off of ebay. My Harbor Freight one is a direct copy and is every bit as good, I have sheared quite a few 5/16" SS bolts with it and thousands of 10-24. I have used all the other methods prior to this but for me it makes them obsolete.

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Dremel with cutoff wheel will work fine, and a lot more maneuverable than angle grinder. Don't forget to thread on a die first, clamp the die in a vice for work holding and easy dimensioning. If you've got a stationary grinder with rubber abrasive wheel you can clean the ends up and make them all shiney! 

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On 12/7/2020 at 8:55 AM, Feisty! said:

Beware the nut chasing trick - it typically leaves a small but lethal burr ...

If I couldn't buy the right length, I'd make a plate the right thickness and tap several holes, thread bolts into it, cut off, apply to belt sander, remove bolts, chamfer/deburr each individually on belt sander, passivate.

Using carbon steel tools on SS bolts will produce rust from tramp iron ...

A new grinding wheel will not contaminant the SS so no rust. But make sure every tool you use has never touched carbon steel or you will transfer iron that will rust. At work we don't even let the SS touch any carbon steel. The storage racks have inserts over the steel arms and so does the fork trucks so the SS will never touch Steel. Also passivation is a good idea but in practice it doesn't seem to matter as much on cut off bolts. We don't seem to see any issues. 

JJ

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On 12/8/2020 at 2:38 PM, Grande Mastere Dreade said:

wouldn't using an angle grinder with a cutoff wheel heat the bolts so much that they lose their hardness / integrity ?  

304/316 are austenitic steels they can not be hardened by heat so you don't have to worry about losing a heat treat as they won't take a heat treat. They will work harden during cold work so if the threads were rolled or the bolt had been extruded or drawn it could have some strength increase due to that, as long as it wasn't annealed afterwards to prevent corrosion(See below). Even if the bolt had some work hardening it is very unlikely that it will impact the fastened strength. You might lose some of the work hardening bits lowering the strength right at the grind. But the Annealing temperature for 304/316 is around 1,700 degrees F. (Going from memory I didn't take the time to look it up.) I wouldn't expect any temperatures that high more than very short distance from the cut. Which if you are following good practice should be 3 threads proud of the nut. You should never cut a bolt off flush if you want full strength of a joint. The would be far enough away to be a non-issue.

However, the heat can cause corrosion in the future if the temperature was in the window that Chromium Carbide can form. Don't remember the temperature but it is lower than the annealing temperature. In fact when I ran a heat treat shop this was the most common reason we annealed austenitic SS's. Because if you reheat to the annealing temperature it dissolves the Carbides then we could cool to the top of the window that they form at then quench through the window temperatures so no Carbides had time to reform. This was all done in a Vacuum furnace quenching with Helium. Passivation will not prevent this corrosion because it is from Chromium being sucked into the Carbides and leaving the SS unprotected in that area. 

As a side note I hear people say if it rusts it is not true SS or they see a anchor roller with rust on it and think it was built from sub-par material. The material may have been to spec but if the fabricator doesn't have the knowledge or discipline to follow the requirements to keep SS rust free the material doesn't matter. It is not as simple as just the base material. 

JJ

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Don't use a cuttoff for 6mm bolt will spend more time cleaning than any else.  Wood blocks in a vice, drill a couple 6mm holes then split the block in bandsaw. Use the block edge as a guide.  A straight hacksaw blade in a good frame will cut through then quick.  Ideally a portaband would make it a very fast job.  Taper-debur on a belt sander then a bench grinder with a wire wheel.

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There are some incredibly involved procedures being proffered here.

I've been cutting SS bolts to length very simply for 30 years now with never a problem.

Put a nut on and run it down

Cut to length with a cutoff wheel in an angle grinder

Run the nut off to create the burr

Roll the end at an angle on a belt or disc sander to remove the burr and create a small chamfer

Run a nut on for quality assurance.

Install.

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Doing one or two is one thing doing a bunch a little time on setup pays off and gives a uniform end product.  I usually us a hacksaw vise grips and a hand file in the cockpit.  Even a high quality rhodus skinny wheel will heat the bolt alot and you risk gauling the nut on.  I also know many people with decent scars or missing digets from angle grinder cuttoff wheels.  I have done quit a bit of ss fabrication and when possible cold cutting is always more controled and cleaner.

All of that said unless I was in a Ancorage miles from a store I would put the long ones in the fastners spares and buy new ones.  Bag of 100 is cheep.

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3 hours ago, SloopJonB said:

There are some incredibly involved procedures being proffered here.

I've been cutting SS bolts to length very simply for 30 years now with never a problem.

Put a nut on and run it down

Cut to length with a cutoff wheel in an angle grinder

Run the nut off to create the burr

Roll the end at an angle on a belt or disc sander to remove the burr and create a small chamfer

Run a nut on for quality assurance.

Install.

This is what I did for 40 years until I bought the bolt shear I mentioned in the previous posts, a huge improvement, especially if you have a lot to do. Screw it into the shear to the length you want, shear it off, screw it out, install it. As with every job, it pays to have the right tool for the job.

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9 minutes ago, Steve said:

This is what I did for 40 years until I bought the bolt shear I mentioned in the previous posts, a huge improvement, especially if you have a lot to do. Screw it into the shear to the length you want, shear it off, screw it out, install it. As with every job, it pays to have the right tool for the job.

Yeah, maybe for electricians. :-) I've used those. My standards include no burrs to draw blood or snag anything anywhere on the boat. Grinding a chamfer at 45 is required. For those here who must buy new tools for every simple project check out diamond metal cutting blades (safer & cooler) for the angle grinder and the Uniburr chamfer tool.

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On 12/15/2020 at 4:48 AM, GoldenStreak said:

Milwaukee M18 Brushless threaded rod cutter?387200861_Threadedrodcutter(4).jpg.17e03bd25d63dbc3943cb72bc194a16d.jpg

those work well with mild steel not so sure about stainless, have used the 24v makita coldsaw for rod cutting and was surprised how clean the cut was along with how easy to just pop a nut on after the cut, once again not overly sure how a cold cut works with stainless, One question/ query I do have though, 304 and 316 are both non magnetic how is it then after cutting with a hacksaw you can clean up the cut deposit with a magnet........ yeah asking for a friend

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Conclusion:  I took y'all's advice, and when the McMaster Carr guy came by our business, I bought a box of 50 bolts of the right size for $16.10.

 

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You could've spent $160 and it would still have been worth it.

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316 can become slightly magnetic, from welding or cold working (sawing is cold working). EVERY 316 fastener in the US is from China, can't get domestically sourced anymore (well you can get them custom made for about 100x the price). Most 316 tube and plate also from China. For awhile after US sources dried up, I could get European made fasteners, not anymore. In your average SHCS, the Chinese ones can be identified by the head not being concentric with the shaft, and the socket drive not concentric with either. 

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16 hours ago, DDW said:

316 can become slightly magnetic, from welding or cold working (sawing is cold working). EVERY 316 fastener in the US is from China, can't get domestically sourced anymore (well you can get them custom made for about 100x the price). Most 316 tube and plate also from China. For awhile after US sources dried up, I could get European made fasteners, not anymore. In your average SHCS, the Chinese ones can be identified by the head not being concentric with the shaft, and the socket drive not concentric with either. 

The vast vast vast vast vast majority of stainless comes from Taiwan and is really good quality . The US setup stainless manufacturing there in the 1980’s, before that stainless was expensive. Chinese stainless is relatively new. Most products are marked with the alloy 304 or 316 and the country of origin. Beware of Chinese 302. It’s magnetic and rusts quick. 
 

 

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7 hours ago, CaptainAhab said:

The vast vast vast vast vast majority of stainless comes from Taiwan and is really good quality . The US setup stainless manufacturing there in the 1980’s, before that stainless was expensive. Chinese stainless is relatively new. Most products are marked with the alloy 304 or 316 and the country of origin. Beware of Chinese 302. It’s magnetic and rusts quick. 
 

 

Perhaps in Australia. In the US, any box of fasteners must be marked with the country of origin. Most SS fasteners are PRC, some are Taiwan. Same with tubing and plate. I'd agree that the Taiwan fasteners are typically a little better quality than PRC, but well below the US and European sources that used to be available. 

Aluminum is another product that is coming mostly from China and Russia. The Chinese stuff is typically horrible quality, the Russian not much better. I can still specify "US made" aluminum from my supplier, the cost is about 50% higher but it is well worth it. Machines and anodizes better, and usually tests to higher yields. 

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I spent 4 hours last saturday cutting off bolts at the nut end. Tried a sawzall with the right blade, tried a grinder, hacksaw.

 

What worked, although it kicked out a shit-ton of dust, was a Dremel with a 90 degree attachment, a quick change arbor the fiber reinforced cutting wheels.

 

I could cut 4, 5/16" bolts per wheel or 2,  3/8" bolts. Had a face guard and dust mask.

Damn cut ends falling into your shoes by the ankle were hot.

 

The sawzall and full grinder just couldn't get in flush when maneuvering around all the stuff in a boat.

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19 hours ago, DDW said:

Perhaps in Australia. In the US, any box of fasteners must be marked with the country of origin. Most SS fasteners are PRC, some are Taiwan. Same with tubing and plate. I'd agree that the Taiwan fasteners are typically a little better quality than PRC, but well below the US and European sources that used to be available. 

Aluminum is another product that is coming mostly from China and Russia. The Chinese stuff is typically horrible quality, the Russian not much better. I can still specify "US made" aluminum from my supplier, the cost is about 50% higher but it is well worth it. Machines and anodizes better, and usually tests to higher yields. 

I’m American. I moved to Au 10 years ago. Chinese stainless wasn’t that common in the US 10 years ago. Unless you were looking to buy the cheapest fasteners available. Everything is marked by law here as well. 

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On 1/6/2021 at 7:47 PM, 167149 said:

those work well with mild steel not so sure about stainless, have used the 24v makita coldsaw for rod cutting and was surprised how clean the cut was along with how easy to just pop a nut on after the cut, once again not overly sure how a cold cut works with stainless, One question/ query I do have though, 304 and 316 are both non magnetic how is it then after cutting with a hacksaw you can clean up the cut deposit with a magnet........ yeah asking for a friend

“The most popular stainless steel is Type 304, which contains approximately 18 percent chromium and 8 percent nickel. At room temperature, the thermodynamically stable crystal structure of 304 stainless steel is bcc; nevertheless, the alloy's nickel concentration, as well as the small amounts of manganese (about 1 percent), carbon (less than 0.08 percent) and nitrogen (about 0.06 percent), maintains an fcc structure and therefore the alloy is nonmagnetic. If the alloy is mechanically deformed, i.e. bent, at room temperature, it will partially transform to the ferritic phase and will be partly magnetic, or ferromagnetic, as it is more precisely termed.”

It’s from some Scientific American article. 
 

I would also guess that the intense heat from the friction of cutting cooks off the alloys, leaving more iron exposed. This would add to the work hardening from the cutting. 

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2 hours ago, CaptainAhab said:

I would also guess that the intense heat from the friction of cutting cooks off the alloys, leaving more iron exposed. This would add to the work hardening from the cutting. 

yup, which is why it is recommended that after cutting stainless you re-passivate it. I use citric acid. I've never done it on the cut ends of bolts, but definitely on bigger pieces like shafts and stainless plates.

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Most 304 is very slightly magnetic, including fasteners, plate, tube. Most literature and lots of experience prove this. Perhaps the author of the SA article spent too much time in the lab and not enough in the shop. Most 316 isn't as delivered, but some welding or cold working can make it so, usually less than 304 in its as-delivered state. 

My understanding is that excessive heat doesn't burn off any alloys, rather it can participate carbides and/or change the crystalline structure from austenitic to martensitic. It can be changed back (and the carbides driven back into solution), but that requires a specific heat treatment - passivation doesn't do it. 

10 years ago I could still get good quality non-Asian SS fasteners. This began to change about then and the last US or European fasteners I got were about 5 years ago. You can still get NAS or some other specialty fasteners that are US made. I'd be happy to pay 2 or 3x the price for US (on any high quality) fasteners, if I could get them. 

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On 1/7/2021 at 1:34 AM, CaptainAhab said:

The vast vast vast vast vast majority of stainless comes from Taiwan and is really good quality . The US setup stainless manufacturing there in the 1980’s, before that stainless was expensive. Chinese stainless is relatively new. Most products are marked with the alloy 304 or 316 and the country of origin. Beware of Chinese 302. It’s magnetic and rusts quick. 
 

 

In our experience, 304 is not so great compared to 316. Over time, the 304 corrodes (rust) much more and heads fail on the hi load stuff.

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7 hours ago, Irrational 14 said:

In our experience, 304 is not so great compared to 316. Over time, the 304 corrodes (rust) much more and heads fail on the hi load stuff.

At the very least the 304 stains much easier in a salt water environment. I think of 304 as construction grade(decking screws) and 316 as marine. We do have some trouble in AU getting all of the boating(inch scale) fasteners in 316. 
 

It’s another of those weird AU not metric industries. We primarily use inch fasteners on boats. The metric fasteners are used for some Ronstan fittings or some electrical parts. Everything else is held on with 1/4-20’s. Just like the States

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Getting back to cutting bolts. My mentor who happens to be a now retired composites/structural engineer at the Boat, liked the vise grips.

We would install the jib tracks with 1/4” aluminium backing strips. 1/4-20 flat head machine screws and nylocks. After torquing we would grab on with the vise grips and lightly wiggle the bolt until it work hardened and snapped. Take a file and dress the burr. If you got a ton to do this is very fast. 

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4 hours ago, gewoon ik said:

Aluminium and stainless mixed. Good way of making sure you have jobs on board.

How would you mount Jib track?

Aluminium fasteners?

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On 1/7/2021 at 10:34 PM, CaptainAhab said:

The vast vast vast vast vast majority of stainless comes from Taiwan and is really good quality . The US setup stainless manufacturing there in the 1980’s, before that stainless was expensive. Chinese stainless is relatively new. Most products are marked with the alloy 304 or 316 and the country of origin. Beware of Chinese 302. It’s magnetic and rusts quick. 
 

 

When I was working in China the salesman would turn up with samples. Asked what the material was, he would ask what I wanted it to be. Happy to supply mil specs to any standard needed. :lol:

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That reminds me of the Horse Cow, a long gone submariner bar near Mare Island. My friend ordered a Heineken. Completely deadpan, the barmaid asked, "do you want that in a Bud or a Miller bottle?"

The vise grip method described above is not going to make removing those fasteners easier, when the time comes. But I could see doing it on Other People's Boats. 

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Get a clear plastic water bottle.

Put the dremel head into the cap end. Cut off a wee bit of the cap if required. Tape to dremel body.

Then cut off other end, about 1/3 down from cap (depending on size of dremel tool etc)

Insert cutting wheel in dremel. Proceed to cut off bolts. The plastic water bottle acts as a guard to capture _some_ of the dust.

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Back when I used to work for production boat builders, the vice grip method was the only method of snapping off the bolts after they were nutted up tight.  49 years later, I still swear by the vice grip method system with no issues.

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Makes a great cheese grater overhead if you don't have a liner covering everything.

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14 hours ago, SloopJonB said:

How would you mount Jib track?

Aluminium fasteners?

You can put the plastic washers between.

But i was more refering to the alu backinplate.

 

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1 hour ago, gewoon ik said:

You can put the plastic washers between.

But i was more refering to the alu backinplate.

 

What would you use for backing plates other than G10. The first time we used those was the early 2000’s. Before that it was either stainless fender washers that look like shite and possibly crush the core. Or some nice 1/4” x 2” 6061 that you can paint if you feel the need. 

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6 hours ago, View from the back said:

Back when I used to work for production boat builders, the vice grip method was the only method of snapping off the bolts after they were nutted up tight.  49 years later, I still swear by the vice grip method system with no issues.

You represent everything that is wrong about the marine industry. Congrats.

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49 minutes ago, gewoon ik said:

I have used a strip of SS in the past. 

Or indeed the big washers.

I use what are called Heavy Fender Washers. Double the thickness, eight times the stiffness, of the typical SS fender washers that usually deform into the wood or laminate before spreading significant load to their edges. Often with G-10 in hidden places, Interior matching furniture ply where appearance is a plus.

 

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