Thread: Best way to cut up a handsaw

Suggest you one of the Ian's from the hand tools unpowered forum, I'm pretty certain one of them has done it with great success.

https://www.woodworkforums.com/members/2992-ianw/

https://www.woodworkforums.com/members/15763-ian-wells/

The hard point saw will likely be with induction hardened teeth and for most knife use, may be much too thin unless you are talking fillet knifes.

Its a bit iffy to determine if such blades will hold an edge.The quality of the saw and therefore the steel will be the determining factor

The best way may to cut your blade may be with an angle grinder fitted with a thin section blade-caution is required.

Failing that, straight line cuts may be made along a(blade) straight line mounted in a vice at jaw top line. One simply cuts along using the vice jaw top surface as a guide.

Grahame

Hi,
Something I have read about but never tried for cutting "hard saw blades"(whatever that means from a book that the 19th edition was printed in 1895). Sounds like it would take awhile.

Stuart

You will definitely need to reharden the metal on a hardpoint saw if you want to use it as a knife. I would also avoid using any of the metal around the teeth as it could have a crack that could spread when using the knife.

I agree with Graeme that it will be too thin for most knives. It depends on what size knife you want to make - if the cutting blade is any longer than about 100 mm there is a possibility that it will buckle when it is re-hardened and tempered.

Hey you have nothing to lose - give it a while. They are easy to cut with a think kerf cutting wheel. I have a water cooled thin kerf cutting wheel in an old table saw that would be perfect for cutting up such a piece. If you were close by you could come around and give it a shot!

I used a ultra thin cutting disc on my 100mm angle grinder .
They are much easier to control , light cuts = less heat

Kev

Hmm, the centrepunch idea is interesting, but I doubt I have that much patience

I followed links to the unpowered hand tools section, and somehow lost a few hours. Found an idea posted I think by IanW or Grahame Collins suggesting clamping the blade between two pieces of thicker steel and running a cutting wheel along the edge that looks like it should work well. The original suggestion said 3/16" thick, but I'm a metric kind of guy so it might differ slightly. I'll give it a try and see how quickly it heats.

I know it will be too thin for a large knife, but I'm just thinking of small utility type knives, and basically having fun using something that's otherwise pretty useless. Besides, I like edged tools. I'll see how it goes with holding an edge, and if it's too soft I'll have a bash at heat treating it. Not sure my torch is hot enough to harden it, but it can't hurt to try.

Thanks for all the suggestions guys!

Hi Beetle,

I can suggest two ways..

1. Score and snap... you need a carbide scribe and score a nice deep line, then mount in a vise, or clamp between a couple of boards and whack with a hammer, then you mount a search for the bit that broke off...

2. If you have an angle grinder with a thin cut off wheel, clamp a couple of strips of 1/4 inch steel along the line you wish to cut, this does two things, first it provides a guide to run the angle grinder along, second it serves as a heat sink so you don't change the temper.



Most saw plate will be fine for a knife, but usually it's tempered to spring temper for saws, it would be better if you could heat treat it, and temper a bit harder.... If you want a good knife that will take a razor edge, try and get some O1..

Also, there are a lot of very good knife making forums, it would be worth while searching around a few of those.

Regards
Ray

I have actually been thinking the same thing..
I have about 7 or 8 cheap stainless steel boot knives scattered around the workshop for general cutting etc. I have been trying to find a supplier of plain carbon steel boot knives for a while now with no luck. Stainless steel is no good for holding an edge. It would be so much cheaper to buy than to make them.

It all comes down to the steel they use in the blade.
You will have no problem with a small burner getting it to the right temperature. Its a very thin blade. Just make sure you move your torch around to keep it even.

If you want to test it cut a small piece off, heat it to a little more than cherry red and plunge it into warm oil. Put that piece in a vice and hit it with a hammer to see if it snaps.
If it bends, try quenching it in water. If that fails it becomes more difficult to try and harden it.

Fingers crossed it snaps!

Make sure you put on some goggles as it can shatter like glass!
Oh and have something to smother the can of oil as it quite often can catch on fire!

Stainless can hold an edge, it just depends on the grade. Back when I was into knives a bit more 440C was a common grade for decent working knives, and there were a couple of others as well I don't remember now. The treatment processes can be a little more complex though.

Yeah, I was going to be playing with some test samples to see how well they hardened up. Thanks for the reminder about the oil bath catching fire though - that's something fairly important I'd forgotten. I happen to have a tub of old dirtbike engine oil I'll be keeping now too . Wonder if it makes any difference that it's synthetic?

Originally Posted by Ben Dono

Oh and have something to smother the can of oil as it quite often can catch on fire!

Plunge vertically into the oil, and move it around a bit, just keep it in the oil until it cools, it will only catch fire if you pull it out too quick.

Regards
Ray

Tisk tisk Ray, up and down

Originally Posted by RayG

Hi Beetle,

I can suggest two ways..

1. Score and snap... you need a carbide scribe and score a nice deep line, then mount in a vise, or clamp between a couple of boards and whack with a hammer, then you mount a search for the bit that broke off...
.
.

I doubt that will work on the hard point saw blade material.

Originally Posted by BobL

I doubt that will work on the hard point saw blade material.

Hi Bob,

Actually it does, it's around 45 Rockwell C, and bends a bit before it snaps, whereas 1095 give a nice clean snap and the offcut goes whizzing off across the workshop, this stuff just cracks and falls off... much less satisfying.

Regards
Ray

Originally Posted by RayG

Hi Bob,

Actually it does, it's around 45 Rockwell C, and bends a bit before it snaps, whereas 1095 give a nice clean snap and the offcut goes whizzing off across the workshop, this stuff just cracks and falls off... much less satisfying.

Regards
Ray

Nice - I'll have to try it!