Scraper Metal Suggestions

[Joel Ficke]

Any metallurgists out there who could suggest a good metal type for traditional card scrapers?

One vendor suggested CPM M4 but high speed steel seems like overkill and is really expensive. I have been gravitating towards SAE 4130 or AMS 6350 but not sure if this is the right balance for price, hardening and edge retention. Any ideas what most scrapers or bandsaw blades are cut from?

Thanks in advance for any help you can provide.

[Mike Siemsen]

Joel,
1095 spring steel from McMaster Carr makes great card scrapers. We made saws from it and saved the drop for scrapers. It comes in several thicknesses. I had it sheared at a local shop. the other option is old handsaw blades, I cut them up with a muffler cutter from Harbor Freight.
Mike

[Bruce Haugen]

When Pete Taran and Patrick Leach were making the Independence saws and scrapers, they used 1095. I got a card scraper from the Leachmeister, and it's the best one I have.

[Joel Ficke]

Mike and Bruce,

Thanks for the 1095 pointer.

Mike as I recall the saw material we got was already hardened. Did you do that after having the teeth cut or did it come hardened? The reason for asking is that I'm wanting to laser-cut the stock and am curious if the metal will need hardening after that. I assume so, but you may know more specifics.

Thanks again guys.

[george wilson]

Laser cutting will de-temper the edges of your scrapers. Allow at least 1/8" extra,and carefully grind it away. Even 1/8" may not be enough. I don't know how large an area the laser leaves discolored on a given thickness of metal.

Yes,the 1095 spring steel comes already hardened to about 52 RC.. It would be VERY difficult to harden thin sheets yourself without a disaster resulting. It needs to be done in a continuous production method. The old timers had to do it in ovens,but probably stacked their blades together,as you couldn't even get a piece of spring steel into the quench before it cooled off. I have made small leaf springs,and had to hold them very close over the quench,and instantly dunk them.