Tool steel or not tool steel, that is the question !

[JimDawson]

Hi Jim, thanks for the input. Do you, other then MCMaster have any books you would suggest I read ? I`m not looking to become a metallurgist but a good understanding of what metals to use for what purpose and why, plus maybe dive into it a little deeper would be ok. You said for applications requiring hardness, well I`m not sure what would require hardness and also how hard ? I also want to learn a little about hardening metals..Any info would be greatly appreciated. Thanks, AJ

The catalog from Pacific Machinery & Tool Steel has a wealth of information in it. That is where I learned a lot about the different alloys. I used to buy a lot of material from them, but not so much anymore because I'm not doing much tool & die work. Here is the web link to them http://www.pmtsco.com/metalproducts.php The product descriptions have about the same information as the paper catalog.

Interestingly, the project I'm currently working on is a tool & die project and has a number of different alloys in it. A36 for the frame, A2 for the punches & dies, 8620 for the feed rollers, 4150 for the punch & die holders, and 4340 pre-hard for the crankshaft. It really takes time and experience to know what steel to use where. The 8620, 4150, and 4340 all came from McMaster, the A36 came from the local steel yard. The punches & dies came from Dayton Progress and I spec'd A2 as the tool steel because I'm not punching an abrasive product. D2 is a more wear resistant tool steel.

How hard? Depends on the application. For punches & dies R60C or better. A truck axle in 4150, maybe R35C or so. Bearing surfaces need to be pretty hard, R60C or better. Die & punch holders in 4150, the annealed state is fine, don't need to be hard. Automotive transmission gears, need a very hard surface, but almost annealed inside for toughness, so these are normally induction hardened and quick quenched. The inside of the gear never gets all that hard. So you can see there is a lot to this