Help - Specific Question cutting hardened A-2 / 51200.

[Dt_Trainer]

The good news: A friend of mine who owns a printing operation gave me 3 of his old paper cutting machine cutter blades. These blades were professionally sharpened by a local sharpener and have become to short for his machine. The blades are 3.5 feel long, 3.5 inches wide, and ¼ inch thick. I called the sharpening company and found out that the blades are bi-metal. The rear of the blade is possibly 51200 on the back of the blade(the owner wasn’t sure) and it’s soft enough to drill with a hand drill and a regular high speed drill, the front cutting edge which is about 1 inch of the blade is A-2 which has a razor sharp edge chisel ground along the whole length of the blade. I have laid out my blades diagonally across the blade so that I can get the front of my point to be A-2 with the supplied chisel grind, and the rear of the handle will be the 52100 softer material.

The bad news: The front of the blade is hard, I have attempted to drill it with a carbide drill bit and my drill press at a fairly low speed and a high speed and have found the edge really hard to drill.

I have attempted to cut the blade with my chop saw but because of the angle I want to cut, it is not working and because the blade is ¼ inch thick it is causing a lot of heat to generate.

What are my options:

If I cut the blade with a torch will I be able re heat treat it since the front is A-2 and the rear is 52100?

I would have the blades water cut if it was economical but I still have to grind the blades so I will be generating a lot of heat grinding since I have a lot of stock to take down.

Any opinions would be appreciated.

Thanks,

Jim


------------------
The warrior will endure great personal hardship in order to stand on a hill, howl at the moon, and proclaim his domain over all he surveys. Fredrick Lovert- Author

 

[raker]

It would kind of depend on how many blade you want to get from the piece of blade. Personally I would torch it, plasma arc cut it or whatever. Grind to shape without worrying about the lost temper. When you get the blades close to final (90% complete), I would normalize twice and anneal. This will put the blade in a soft state to do your drilling, filework, etc. I am not familiar with A2 but the 52100 will be ready to heat treat. If you are doing very many blades at one time, it will be easier to wire them together and do them all at the same time. If you etch the steel before you cut, it should show the bonded line, you could cut the two apart and not worry about the difference in the heat treat.

------------------
Ray Kirk
www.tah-usa.net/raker

 

[Dt_Trainer]

Thanks Raker, I have decided to cut my blanks out with a torch unless someone is near by the Milwaukee, Wi. area and can spare some time on their Plasma Cutting System. Raker can you spare some knowledge on how to normalize, anneal, and heat treat the 52100 a web site link will be fine. By the way I Looked at your website and it looks great.

So what do I do with the A2 to re-heat treat it I have read here that A2 is really hard to Normalize and Anneal. Anyone with A2 experience want to help me out.

I really don't want to throw out these blades and I bascially plan on making some nice using knives for friends and family as presents out of these bars.

Thanks in advance,

Jim


[This message has been edited by Dt_Trainer (edited 01-16-2000).]

 

[Kevin Wilkins]

Both A2 and 52100 are inexpensive steels. Why go to all that trouble for $50 worth of steel? Buy new steels - unless you forge the blades – and save yourself a LOT of headaches.
If you plasma cut the blades you'll still have to anneal before grinding...

------------------
www.wilkins-knives.com

 

[Chuck Richards]

A2 is an air hardening tool steel, it requires a long drawn out anealing process. I agree that purchaseing new steel is a better alternative to cutting with a torch. Once the steel is heated beyond critical temp it needs to be annealed. Grinding away the torched portion is always an option. Then again you will eat up a lot of grinding wheel or belts grinding on hard A2..