Question on making Blades from Saw Blades-Now with pictures

Started by Mogorilla, January 19, 2015, 07:10:48 AM

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Mogorilla

Question on making Blades from Saw Blades.   Do you have to temper/heat treat the steel when done?   I have several circular saw blades that are too dull to use and thinking of making a few blades.    I have seen some people making them on the web and it is about 50-50 whether they do any heat treating after shaping but before sharpening.   As far as the steel goes, I have tried to drill a hole in it, making a line of holes to give a good place to break, to no avail.   Steel too hard for my drill bit.   I can get a hole, but it takes a while and pretty sure after drilling too, my new bit is toast.   I like to hang things, so I have drilled small holes in regular hand saws and the drill went through them quite easily, with one of the larger hand saws being of a comparable thickness.  

Thanks,

Camano Ridge

Mogorilla, a lot of the older circular saw blades were made from L6 it is a good steel for knife blade. THe blades with carbide tips are goin to be softer metal. Newer blade syou have know idea what alloys are used different manufactures different product so heat treating can be problematic. If you have a hardened blade you can cut it out using a cut off wheel on a angle grinder. The problem is you will have to keep water flowing over the blade to keep it cool so you don't loose it's temper. Once you have the shape cut you will need to grind the blade. Again this will be a lot of work on a hardened blade and you will have to keep it cool during the grinding process . If you get any color change as you are grinding then you are effecting the temper of the blade.

Most of the time when you see a knife being cut out by drilling many holes it is a blade that has been anealed , softened by heating. A lot of the people that make you tube videos showing you how they made a knife out of a saw blade are not knife makers and have made something that looks like a knife but with out proper heat treating will not be a usable knife for the long term.



You can soften a saw blade to make it easier to work and then heat treat it. With a little practice and some guidance you can heat treat some metals with an oxyactelene torch and a toaster oven.

There are some tutorials on making saw blade knives on balde forum and British blades forum.

As to your hand saw blade the heat treating is different. It is going to be heat treated so that the metal is softer nearer the spine and harder at the teeth. THis is to allow the blade to have some flexability yet have sharp teeth that will hold a n edge.

Mogorilla

Thanks for the info.   I made one cut with a dremel and kept it cool with water.   I do a lot with hand files, and a little with bench top grinder, so I will make sure to keep water handy.   In the past I did one from an old knife and made sure I could hold onto it bare fingered while working the grinder.   

Camano Ridge

If it is hardened metal you may find that your files just glide across the surface without grabbing metal.

Blair

I stopped offering information on tempering and hardening of modern steels many years ago.

Most folks just don't get the concept/idea of hardening and tempering of the historical common steels... let alone the heat treating of the modern steels that are available today.
This, info, gets very complicated by/when comparing it to historical steels.
I make this suggestion based on my knowledge of historical metal working.
My best,
Blair
A Time for Prayer.
"In times of war and not before,
God and the soldier we adore.
But in times of peace and all things right,
God is forgotten and the soldier slighted"
by Rudyard Kipling.
Blair Taylor
Life-C 21

Bruce W Sims

This is a real help....For a long time I was sure that the whole matter was a non-issue.
In fact, I was of a mind that a guy WANTED to anneal a steel to make it more workable
and then simply temper the project as part of the final stages. What I am hearing is that
once the temper is lost, it can't be redone. Am I reading right?

Best Wishes,

Bruce
Best Wishes,

Bruce

Blair

Bruce,

You are incorrect!
All common metals can be annealed.
This is done through heating the metal, a little or a lot depending on the type of metal.

Hardening and tempering of Steel can be very different process, especially with the modern, very exotic steels in common use today.
All of these factors need to be known by the Smith to get the procedure correct for that application.
My best,
Blair
A Time for Prayer.
"In times of war and not before,
God and the soldier we adore.
But in times of peace and all things right,
God is forgotten and the soldier slighted"
by Rudyard Kipling.
Blair Taylor
Life-C 21

Camano Ridge

Bruce, just to add to what Blair said. WIthout knowing the specific metal you may not do the right heat treating process. Some steels are air hardening some steels need oil quench etc. spring steel like 5160 is fairly easy to heat treat. Heating to non magnetic then quenching then I use a torch to heat the spine and bring the color band bow the blade withot reaching the edge then heating in an oven about 300 degrees for a couple hours doing a couple of cycles. Please don'ttake this as an all encompassing tutorial on heat treating, there is a little more to it. When heat treating D@ the process is a little different when doing stainlesses and CPM (Crucible Powder metals) the process is a lot different. You definetly can soften a metal then reharden it if you know the process.

1961MJS

Hi

I live within 50 miles of Jantz Supply so I can get pretty much any knife steel I want.  I have a very basic questions though.  Is there any advantage to forging, quenching, and tempering a blade as opposed to just cutting the shape out by hand, grinding it to shape, and then quenching and tempering it? 

The reason I ask is that I'm thinking about building a huge pre-Civil war Spear Point Bowie knife.  I can build or find someone with a place to quench a blade, but I don't have the desire to make two of these so I don't want a forge all that bad. 

Thanks


ChuckBurrows

Quote from: 1961MJS on July 12, 2015, 05:34:30 PM
Hi

I live within 50 miles of Jantz Supply so I can get pretty much any knife steel I want.  I have a very basic questions though.  Is there any advantage to forging, quenching, and tempering a blade as opposed to just cutting the shape out by hand, grinding it to shape, and then quenching and tempering it? 
Thanks



There is no real advantage to either method as to final quality - despite that statement some folks will argue that a forged blade is better - but many straight across comparison tests between the two methods show there is no real advantage to either method - there are excellent knives made using both methods as well as crappy blades - the manufacturing method alone is not a sign of quality.

FWIW - I have been building knives since 1962 - professionally since 1971. While I generally forged my blades that had more to do with the methods used in the past since my main interest is in historical blades. For historical blades the closest modern made equivalent (based on the chemical analysis of several original trade blades) is the 10XX series of simple high carbon steels starting with some thing on the order of 1065-1084. Hardening/tempering of blades to a certain hardness is also generally different on historic blades. Based on the hardness testing of 3 dozen relic blades I did back in the 1970's the blades averaged 50 Rc where as todays blades general run 58Rc or higher dependent on the steel used. Me test results of old blades (all dating from 1750-1850) is in keeping with tests by several others interested in the blades of the past.
aka Nolan Sackett
Frontier Knifemaker & Leathersmith

Cliff Fendley

Quote from: 1961MJS on July 12, 2015, 05:34:30 PM
Hi

I live within 50 miles of Jantz Supply so I can get pretty much any knife steel I want.  I have a very basic questions though.  Is there any advantage to forging, quenching, and tempering a blade as opposed to just cutting the shape out by hand, grinding it to shape, and then quenching and tempering it?  

The reason I ask is that I'm thinking about building a huge pre-Civil war Spear Point Bowie knife.  I can build or find someone with a place to quench a blade, but I don't have the desire to make two of these so I don't want a forge all that bad.  

Thanks


From a metallurgical standpoint there isn't an advantage even though there are those that will swear you have to hit it with a hammer to make it a good blade. Actually every tempering cycle where you get that small amount of scale you can actually lose carbon.

As Chuck said in his post, unless you want to beat the blade into shape for historically accurate reasons you get no other benefit from hand forging. Keep in mind, all of the steel is forged when making it into bars anyway.

As a knifemaker we have available to us the best steels today that we can easily obtain all the info from the analysis of the steel to the exact recipe for austenitizing and tempering that has all been laboratory tested. You can use these tools to develop the ideal blade for an intended application and duplicate that time and again. No need to take a chance of screwing it up by beating on it.
http://www.fendleyknives.com/

NCOWS 3345  RATS 576 NRA Life member

Johnson County Rangers

ChuckBurrows

The only advantage to forging over stock removal is that with forging you can take an odd shaped piece of steel (such as a 52100 bearing or 5160 John Deere rods, etc.) and turn it into a blade - with stock removal you are limited to a shape similar in size and shape to the finished blade, but that's not so much a matter of quality as it is of limitations.
aka Nolan Sackett
Frontier Knifemaker & Leathersmith

1961MJS

Thanks Gentlemen

I have a 2 inch wide by 0.25 inch thick and 18 inch long piece of 5160 High Carbon Steel from Jantz.  I'm pretty sure I can get the shape I want from the Bowie Knife book with a hacksaw, a grinder, and a belt sander.  I know that making a Samurai Sword requires hammering and folding, but I had hopes that I could do this without a forge.

Thanks again.

Mike

Mogorilla

I will be posting some pictures soon, but I finally got around to quenching and tempering a blade shaped from a circular saw blade.  Other than the fact if I ever do it again, I need a forge, torches in each hand to get it to temperature takes forever.   I need to work on patience, so it was a good exercise for me.  Took it up until a magnet would not react anywhere, then quenched in peanut oil.   Did the tempering in the oven, 450 for 3 hours.   I tested the blade with a  file after quenching, no mark and it was stiff, no bend at all.   After tempering, it has a bit of flex.   It will be a "scalper" so working on the hafting at the moment and trying to remember my dang password for Photobucket!

ChuckBurrows

Mike - you should have no real trouble making the Bowie you want with the tools you have = the first hundred or so knives I made were made mostly that way.

Mo - do a search for one brick forge and also coffee can forge. They are small in size yet can do a yeoman's job as long as you understand the limitations. Also they are pretty cheap to use and on the one brick forge I use a Mapp torch for the heat or hook the tip up to bigger propane tank. For the coffee can forge I started out using a weed burner, but later built a burner per instructions on the internet.

Anyway they are much more efficient than just torches, yet are easily and cheaply built. I keep a one brick inside in my shop and it's been one of the handiest tools ever and doesn't over heat me like a full size forge
aka Nolan Sackett
Frontier Knifemaker & Leathersmith

1961MJS

Thanks Chuck

No hurry, I've been spending 10-12 hours a day at my "real" job, so I'm getting no where fast on knife and sheath making.  I'll have to post pictures of a butcher blade and buffalo leather Indian style sheath I made. 

Thanks

Mogorilla

Hello,
Have not made a sheath, but have completed the knife (still needs more sharpening)


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