Saw blade metal? Is it good for knives?

J

Jastab

Joined
Jan 31, 2013
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Hey bladeforum peeps, I haven't been on in years so forgive me if I'm in the wrong section. But I have a question, a guy I know gave me an old rock quarry saw blade. It's about 3' round and probably 3/16" thick. I was seeing if anyone has experience on using these blades or any other saw blades for knives. I do have access to a waterjet and can cut with no heat transfer. I assume these are already hardened steel of some sort. Any advice or knowledge would be greatly appreciated!
 
Circular saw blade bodies typically have a medium temper. Was this a diamond edge blade, or just a friction blade? If a sample can be hardened, you can make a workable knife from it. Most likely this is medium carbon steel, like 1060 or 1075.
 
If it is/was diamond or carbide tipped, then the body will be low carbon and not able to be hardened.
 
The blades that are able to be used are Very old saw mill blades, old Mill band saw blades, and old two man/cross cut saws.

Though keep in mind that some cross cut saws will be worth more (sometimes Much more) as a saw, and not chopped up for knives.
 
I could scrap it, my initial thought was it would be hardened already. Makes sense that it's not and the diamond does the cutting. Bummer, I thought I had a good metal to use.
 
On carbide tipped circular blades for wood cutting the blade bodies are medium carbon steel hardened to low 50's Rc. Mild steel is too weak to resist lateral deflection and too soft to support the cutting tips that transmit impacts to the steel shoulders. The brazing compound helps to absorb these impacts, being softer by far than the tempered blade body. I suggest two easy things to try. First, strike the blade with a hammer while it rests on a trio of hard objects and listen to the ring it produces. Harder steel makes a higher pitched sound. Second, cut off a piece and heat red hot with a torch, then quench in water. Can you cut it easily with a file after quenching? If so, recycle it. If not, then it'll make a passable blade. Obviously, a blade would need to be tempered back from as-quenched hardness.
 
No one stated that the usable temper was well worn WHEN the blade was retired.
Watter-jetting, and grinding will be easy.

Getting the blade re-hardened will require multiple "normalization" cycles. This is IF you can determine whom made the saw, and IF they will divulge the steel used.
Rusting or oxidation is not a primary concern in (industrial) saw material, as they are meant to be used continuously, and the manufacturer will want a reputation for long life vs shinny steel. (ie: high carbon)
The best blades are MEANT to be re-coated.
Google https://www.google.com/search?clien...QjPTVAhVF6SYKHZRCB2cQBQgjKAA&biw=1098&bih=517

There are some phenomenal steels used in many saws. They are made to last as long as possible.

Look up where/when the blade was made, and determine WHAT steel was used.
I would NOT throw anything away without knowing.
Spark test everything.

It could be junk or it could be a treasure.
 
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Bill1170 said:
On carbide tipped circular blades for wood cutting the blade bodies are medium carbon steel hardened to low 50's Rc. Mild steel is too weak to resist lateral deflection and too soft to support the cutting tips that transmit impacts to the steel shoulders. The brazing compound helps to absorb these impacts, being softer by far than the tempered blade body. I suggest two easy things to try. First, strike the blade with a hammer while it rests on a trio of hard objects and listen to the ring it produces. Harder steel makes a higher pitched sound. Second, cut off a piece and heat red hot with a torch, then quench in water. Can you cut it easily with a file after quenching? If so, recycle it. If not, then it'll make a passable blade. Obviously, a blade would need to be tempered back from as-quenched hardness.
Click to expand...
By heating to "red hot" he wouldn't be at a high enough temperature. He would have to get over the Curie point.

Preheat your oil to 130° to reduce the likelihood of a gas jacket. If using water, use room temp water, or slightly warmed. Around 85°c (185°F you start to see increased failure rates).

Have a magnet ready, and heat a 1"×1" coupon to non-magnetic and let it sit in the heat for a few seconds. Make sure your coupon is no longer magnetic.

Quench your coupon and rinse with fresh cold water once it is warm to the touch. Hover your hand.over the coupon so you don't risk burning the crap out of your hand.

Hit the coupon with a file. You will have to get through a bit of steel that had the carbon burned out of it, but if there is a hardened core, you should hit it after .020"-.040".

If it didn't harden, well now you have experience in figuring out how to do so.
 
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Zombie411 said:
Look up where/when the blade was made, and determine WHAT steel was used.
I would NOT throw anything away without knowing.
Click to expand...
This is easily done by simply looking on the blade to see if it is stamped. If it isn't stamped or written, call the place it was sourced from and speak to someone there. If they seem skittish about handing over that information, tell them that you or your son, (cousin, nephew, whomever) is doing a project in vocational school this year, and you are trying to find out the alloy for him/her.

If you can get the name of the company that makes the blade, give them a call and see exactly what they use.

Good thinking Zombie.
 
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