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Thread: What to use to cut stainless screws?

  1. #1
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    Default What to use to cut stainless screws?

    My restoration project includes having to cut through a long length of 2x2 fir that has a series of 1" stainless steel screws fastening it to 35 year old mahogany plywood.

    If I remember right, stainless does not cut very easily. Anybody know what kind of blade I should be looking for?
    "Joan of Arc is alive and medium well"

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    Default Re: What to use to cut stainless screws?

    A borrowed saw?

    (ar ar ar)

    What will you be using to cut the wood with? Since you are cutting it, can we assume you won't be pulling the screws, so they need to be ground flat to the ply??
    "The enemies of reason have a certain blind look."
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  3. #3

    Default Re: What to use to cut stainless screws?

    any good metal bade should cut it,no such thing as high speed.use oil as cutting fluid if the wood doesn't care.

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    Default Re: What to use to cut stainless screws?

    I assume it's not possible to remove the screws.(?) That would be the best route to take. You're right though, at least to an extent. While ss is generally quite tough, those screws will yield to a good quality hacksaw blade. If possible a bit of lubrication will help-- anything slippery will be worthwhile- oil (even vegetable), liquid soap, etc.

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    Default Re: What to use to cut stainless screws?

    Can you get at them with a cut-off wheel on an angle grinder?
    As usual, a photo would help.
    Steve Martinsen

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    Default Re: What to use to cut stainless screws?

    Yep - a photo would make all the difference.

    If possible, I'd use a 1.6mm cutting blade on an angle grinder.... use some thin mdf as shielding against sparks. Otherwise, if the heads are buggered (a technical term, meaning stuffed)... you can dig a hole around them with an old cheap chisel (if you use a good one, it will rapidly become an old one) and use vicegrips to clamp the head and screw them out.
    Carpe the living sh!t out of the Diem

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    Default Re: What to use to cut stainless screws?

    Mini Angle grinder with cutting disc and vice grips....

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    Default Re: What to use to cut stainless screws?

    Cutting or drilling stainless is actually easy. You just have to avoid creating heat as this hardens the steel. So, with a drill, keep it sharp and the angle of the point shallower than you'd use for wood, and drill at the lowest possible speed (many electric hand drills will not allow a slow enough speed). You'll know you've got it right when strings of waste begin peeling off (swarf) rather than chips. Use a lubricant. Cutting is similar although as mentioned above, angle grinders, Dremel with the cutting disks etc. do a fine job. But, if access is a problem, a sharp hacksaw blade or a sabre saw with the right blade and the speed cut to minimum should do the trick. If screws are hard to extract, chisel out a little timber under the head and put small Vise-grips onto the screw and twist them out. Rick
    Last edited by RFNK; 06-17-2009 at 10:02 PM.

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    Default Re: What to use to cut stainless screws?

    the trick to cutting stainless, or any metal really, is to have sharp blades. get several extras. as soon as it goes dull, change. you'll just burn out your tool (and your temper!) trying to get a little more out of a blade.
    Member of the Loyal, Mostly-Noble, Elite and Most Ancient order of the Laughing Polar Bear Cap Society.

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    Default Re: What to use to cut stainless screws?

    Hack saw with 24 T per inch, or 4 inch grinder with cut off wheel and safety goggles.
    I love the smell of fresh cut plywood in the morning.

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    Default Re: What to use to cut stainless screws?

    Forget the safety goggles.... they mean you miss the little pleasures in life, like being sandwiched on the bunk between my very cute doctor on one side and her equally cute nurse on the other as they peer into your eyes...... then they squirt salt water into your eyes. Yep, that was Tuesday.
    Carpe the living sh!t out of the Diem

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    Default Re: What to use to cut stainless screws?

    You could lie about having gotten something in yer eye.
    R
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    Default Re: What to use to cut stainless screws?

    If you are cutting wood in which the SS screws are embedded use a bi-metal blade in a Bosch jigsaw or a reciprocating saw. A fine-toothed metal cutting blade like a hacksaw is next to useless for cutting wood. If you slow down when you hit a screw those bi-metal blades will cut all day long.
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    Default Re: What to use to cut stainless screws?

    And if the sawzall dont work fast enuf... a torch will
    geeze guy...serious question... have you never picked up a hacksaw before today?

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    Default Re: What to use to cut stainless screws?

    In order to reach and cut these screws, I have to cut at right angles, say like a grinder would. A jigsaw for instance, would not fit. I would post a picture if I could figure out how to take one, but I don't think even then it would illustrate the problem.

    It looks to me like being able to cut slowly and with lubrication is what I need to do, whatever the tool.

    On the other hand, trying to reveal the heads and then attempting to back the screws out sounds like the very first thing that I ought to try. I estimate that I need to extract about 40 screws that were installed in 1976 straight through a layer of 3/8" marine ply, then into a one inch fir stringer and then into another lay of 3/8" marine ply.

    Don't know what kind of glue was used. But, I will report my progress.
    "Joan of Arc is alive and medium well"

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    Default Re: What to use to cut stainless screws?

    You haven't even tried to back the screws out?
    Exhaust that avenue before dragging out the big guns.

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    Default Re: What to use to cut stainless screws?

    I have a similar ( but even worse ) issue with cutting stainless steel, So I'll ask here. I received my ballast keel from the foundry. It has 10 SS keelblots (presumably 316), half 1/2" and half 5/8". All of the bolts are too long and the threads cut too short (up to 1 1/2" too short). I have to...

    a) cut more threads to match...
    b) cut off the excess length without ruining the threads before installing on the boat ( no room in the bilge)


    Is it true that cutting with a lesser metal will leave ferrous residue which will rust? Makes sense...If so, can it be ground or polished off? What is the best way to cut through the threaded part of the bolt so that the threads still work? I want very little excess length so that once installed, there arw few threads exposed at the top of the nut. Lastly, does the heat generated fron cutting, regardless of method, effect the metal's chemical behavior, i.e...more rust?

    Help...

  18. #18

    Default Re: What to use to cut stainless screws?

    I have had a good deal of success using a plug cutter in a drill to remove stripped screws. Start slow until a groove is well established and drill down until the screw with plug comes out or you are able to grab on to the screw head with needle-nose vise grips. Match the outside diameter of the plug cutter to the inside diameter of another and you can glue in your repair plug.
    Mike

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    Default Re: What to use to cut stainless screws?

    Quote Originally Posted by Adios View Post
    I have a similar ( but even worse ) issue with cutting stainless steel, So I'll ask here. I received my ballast keel from the foundry. It has 10 SS keelblots (presumably 316), half 1/2" and half 5/8". All of the bolts are too long and the threads cut too short (up to 1 1/2" too short). I have to...

    a) cut more threads to match...
    b) cut off the excess length without ruining the threads before installing on the boat ( no room in the bilge)


    Is it true that cutting with a lesser metal will leave ferrous residue which will rust? Makes sense...If so, can it be ground or polished off? What is the best way to cut through the threaded part of the bolt so that the threads still work? I want very little excess length so that once installed, there arw few threads exposed at the top of the nut. Lastly, does the heat generated fron cutting, regardless of method, effect the metal's chemical behavior, i.e...more rust?

    Help...
    NO PROBLEM....

    You should get a GOOD Die and Stock with the right size Die, The DIE is ADJUSTABLE so the pitch diameter of the screw threads can be set just right... THAT's IMPORTANT...

    Also get from a PLUMBER, a can of CUTTING OIL...it's high in Sulphur content and makes cutting threads EASY...
    Your going to run those threads down further so you have plenty of thread for the nuts to thread onto.

    Clean it up with solvent and shove the bolts up into the boat with plenty of grease or bedding compound or roofing tar repair stuff that comes in a caulking gun size tube at Home Depot. I'd sugest masking the threaded area with electrical tape so the goo doesent get in the threaded area.

    AFTER ...AFTER... the keel is installed in the boat, then cut off the extra bolt length with a hacksaw.

    SIMPLE.... REALLY SIMPLE.... if your not comfortable doing this, find a machinist friend, or a mechanic, or a welder, or a hot rod guy, or a ...well, just about anyone with some machine shop experience to help you.
    Last edited by Gary E; 06-18-2009 at 04:01 PM.

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    Default Re: What to use to cut stainless screws?

    Thanks...
    I've got the die set and finding cutting oil should be no problem. Cutting the bolts off after installing the keel will be difficult. There's no room in the bilge to get a perpendicluar cut with a hand saw or reciprocating saw. A friend has a Fein multimaster...will the metal cutting blades with these do the trick?
    Thanks again!

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    Default Re: What to use to cut stainless screws?

    Quote Originally Posted by Adios View Post
    Thanks...
    I've got the die set and finding cutting oil should be no problem. Cutting the bolts off after installing the keel will be difficult. There's no room in the bilge to get a perpendicluar cut with a hand saw or reciprocating saw. A friend has a Fein multimaster...will the metal cutting blades with these do the trick?
    Thanks again!
    I've only seen that tool shown cutting copper tube on TV... and that aint gona cut a Stainless Bar... my opinion. Couple reasons... that little thing vibrates way to fast for SS where a bite must take a chip, and since it does go so fast, all it's gona do is wear off whatever teeth it has and in the process work harden the SS bar and make it even harder to cut.
    Get a disk sander and use a cutoff wheel.

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    Default Re: What to use to cut stainless screws?

    There are a lot of different types of stainless steel. Some are just unbearable to cut.

    If these are standard screws, standard tools - hacksaw, drill bits, and cutoff wheels should work. Oil may make a mess but helps high speed steel tools.

    The Fein multimaster should not work.

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    Default Re: What to use to cut stainless screws?

    Dremel tool and #406 disks called "dangerous disks." The danger disks are carbide and will grenade if you twitch just a little. No prob, container had a few dozen of these bad boys and given enough time and a hefty supply of Dangerous Disks you could could a car in half.

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    Default Re: What to use to cut stainless screws?

    I had a dremel tool once...cooked the motor on it cutting through ONE 1/2 galvanized carriage bolt (from Lowes). I'm not sure it has the guts for stainless...

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    Default Re: What to use to cut stainless screws?

    On the fire department we use cobalt-moly blades for the sawsall. There is a huge difference between these blades and the common metal cutting blade. We use these to cut cars apart and time is usually of the essence. Admittedly, there is no stainless steel involved.
    Dave

  26. #26
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    Default Re: What to use to cut stainless screws?

    18-8 304 and 316 stainless steels are pretty "soft" metals compared to most carbon steels. "Aquamet" is another "soft" material and I strongly suspect is 316 with maybe a few sprinkles, cookie dough, and whipped cream added to justify the "marine" markup, but this is strictly "shafting" material.

    The hard stuff is used for kitchen knives, surgical blades, and motor driveshafts which need to be hard. 17-4PH Stainless is the hard stuff, but I don't believe fasteners are made from it, unless of course they are going to the moon.

  27. #27

    Default Re: What to use to cut stainless screws?

    Quote Originally Posted by Gary E View Post
    NO PROBLEM....

    You should get a GOOD Die and Stock with the right size Die, The DIE is ADJUSTABLE so the pitch diameter of the screw threads can be set just right... THAT's IMPORTANT...

    Also get from a PLUMBER, a can of CUTTING OIL...it's high in Sulphur content and makes cutting threads EASY...
    Your going to run those threads down further so you have plenty of thread for the nuts to thread onto.

    Clean it up with solvent and shove the bolts up into the boat with plenty of grease or bedding compound or roofing tar repair stuff that comes in a caulking gun size tube at Home Depot. I'd sugest masking the threaded area with electrical tape so the goo doesent get in the threaded area.

    AFTER ...AFTER... the keel is installed in the boat, then cut off the extra bolt length with a hacksaw.

    SIMPLE.... REALLY SIMPLE.... if your not comfortable doing this, find a machinist friend, or a mechanic, or a welder, or a hot rod guy, or a ...well, just about anyone with some machine shop experience to help you.
    For the guy with the SS keel bolts, I agree to cut them after the keel is in and I would use a grinder with a cut off blade. I have an air grinder-cutoff that is only a few inches in diameter that should be able to get into a lot of tight places. They make them with right angle drives and that may work better. Using a Dremmel will not work unless you wan to take forever and go through a ton of little tiny grinding disks.

    Also, cutting the threads may not be as easy as you have in mind. I had to cut some threads on a 1/2 inch bronze rod and tried 3 different style of dies. The problem is that the damn things don't always stay centered so they try and cut threads out the side of the rod after a while. Not a problem if you are cutting another inch, but if you have to go 3 inches, watch out. Unfortuniatley, I don't remember which style of die was self centering. Some of them have a mind of their own. Once they start to go off axis, they just basically get stuck. I was also told that cutting threads on SS is very difficult although I have never tried it (because of that advice I might add).

    Allen

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    Default Re: What to use to cut stainless screws?

    Our local hire place has a thing like a big sabre saw ( I'd guess that you guys would call it a sawzall) with a "demolition " blade in it. Cost about twenty bucks for a morning. The "demolition" blade is designed to cut walls with bolts, nails, sheetmetal and wire in them. Stainless screws would be a piece of cake. I'd be very surprised if you could not get the same thing in your area.

    JohnWelsford

    Quote Originally Posted by film842 View Post
    My restoration project includes having to cut through a long length of 2x2 fir that has a series of 1" stainless steel screws fastening it to 35 year old mahogany plywood.

    If I remember right, stainless does not cut very easily. Anybody know what kind of blade I should be looking for?
    An expert is but a beginner with experience.

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    Default Re: What to use to cut stainless screws?

    Allen,

    Good advice on the centering of the threads...I didn't think of that one. Do you know, specifically, what to look for in a die that would remain centered? I didn't even think of a pneumatic tool...that'll do the trick...there's NO room for a sawzall.
    Thanks
    John McFadden
    Charleston, SC

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    Default Re: What to use to cut stainless screws?

    Quote Originally Posted by Adios View Post
    Allen,

    Good advice on the centering of the threads...I didn't think of that one. Do you know, specifically, what to look for in a die that would remain centered? I didn't even think of a pneumatic tool...that'll do the trick...there's NO room for a sawzall.
    Thanks
    John McFadden
    Charleston, SC
    Most Stock and Die setups have a centering or lead in to keep the dies in the right place 90 deg or normal to the bar being threaded. Take a bolt with you when you look at the tool and screw the bolt into the die and you should see how it works.

    Keeping the bar as long as possible while you are threading it will assist you in making a good job of it... Cut off the extra after it's installed complete in the boat.

  31. #31
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    Default Re: What to use to cut stainless screws?

    I didn't even think of a pneumatic tool...that'll do the trick...there's NO room for a sawzall.
    I guess I don't understand why you don't put the bolt in, mark it for length, take it back out and cut it off?
    Count how many threads it is too long and cut that many off.
    Any more than one thread past the nut is wasted material.
    I cut stainless all day with a hack saw. I have the heaviest frame I could find and the best Lenox or Nickleson bimetal baldes I can find. The blade must be tight - tight - tight. I lubricate the saw blade with cutting oil, a little dab with my finger. Cuts like butter.

  32. #32

    Default Re: What to use to cut stainless screws?

    Quote Originally Posted by Adios View Post
    Allen,

    Good advice on the centering of the threads...I didn't think of that one. Do you know, specifically, what to look for in a die that would remain centered? I didn't even think of a pneumatic tool...that'll do the trick...there's NO room for a sawzall.
    Thanks
    John McFadden
    Charleston, SC
    I do not remember which of the die worked the best and I may have had to use more than one. I do remember the three styles. One was tapered on both sides so it really only cut deep in the center. It was not adjustable. One was adjustable and tapered on one end. One was not adjustable and was tapered on one end. I also have a set of dies that is not tapered. For them you have to taper the rod. They are very cheap and I didn't use them for this job. The idea with the adjustable die is that you can cut shallow threads first and then tighten it up and make the threads deeper. In terms of the die getting off center, it wasn't just at the start. It tended to wonder off a couple inches down the rod. It may be that being off axis by a very small amount at the beginning just accumulates. Or there may be some force that makes the die want to wonder off. I don't know which it is but I strongly suspect the latter. I wish I could be of more help. Good luck.

    Glad the air tool suggesting will work for you.

    Allen

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    Default Re: What to use to cut stainless screws?

    Thanks for the input...Actually D Happ's suggestion was my original plan. I have to admit that cutting the bolts off first gives me the creeps. I think that I'll try to cut them off once the keel is mounted. Thanks again

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    Default Re: What to use to cut stainless screws?

    Cutting SS screws:
    I have a Bosch reciprocating saw, and a Sawzall. For this job I'd use the recipro, with metal cutting blades. The deluxe set would be two recipros, one with a bi-metal blade for cutting the wood up to the screws, then switch to the recipro with the hacksaw blade, and so on.

  35. #35

    Default Re: What to use to cut stainless screws?

    Quote Originally Posted by D Happ View Post
    I guess I don't understand why you don't put the bolt in, mark it for length, take it back out and cut it off?
    Count how many threads it is too long and cut that many off.
    Any more than one thread past the nut is wasted material.
    I cut stainless all day with a hack saw. I have the heaviest frame I could find and the best Lenox or Nickleson bimetal baldes I can find. The blade must be tight - tight - tight. I lubricate the saw blade with cutting oil, a little dab with my finger. Cuts like butter.
    cut enough thread to tighten years later

  36. #36
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    Default Re: What to use to cut stainless screws?

    Threading/Cutting keel bolts sub-thread
    If possible, I wouldn't thread or cut off the studs. I'd use washers to raise the nuts up to the correct height on the studs. The ideal washer would maybe be made out of that stuff made by the company that makes Samsonite luggage, an very high density plastic that's used in FRP boats to replace balsa core in decks in areas with high compression loads.
    This approach would be cheaper and vastly quicker than threading & cutting. It also has the advantage of lifting the nuts up out of the bilge water.

  37. #37

    Default Re: What to use to cut stainless screws?

    Quote Originally Posted by D Happ View Post
    I guess I don't understand why you don't put the bolt in, mark it for length, take it back out and cut it off?
    Count how many threads it is too long and cut that many off.
    Any more than one thread past the nut is wasted material.
    I cut stainless all day with a hack saw. I have the heaviest frame I could find and the best Lenox or Nickleson bimetal baldes I can find. The blade must be tight - tight - tight. I lubricate the saw blade with cutting oil, a little dab with my finger. Cuts like butter.
    to put in & take out is hard work, your bolts should be a tight fit, weld 2 weld rods, or length of wire, and bend the end over, 3mm, use this as a length probe, measure twice, cut the longest bolts first, mark with felt tip, after cutting the thread, round the end of bolt, test a nut on the thread, s/s threads are not smooth, test then drive them home

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