Tool Steel - What do I have?

[lowpass5]

Hello all,
I have what I hope is a simple question for the more experienced machinist on this forum, but one that is not readily explained in the internet searches I have performed.

I inherited a lot of Tool Steel from my father when he passed away and some additional pieces with a machine I recently purchased. There is quite a lot of it - maybe 50 lbs or so and some larger pieces so I would like to understand what I have and make use of it. For the most part it isn't marked other than hand written tool steel presumably by my father. A few of the pieces I got with my machine are factory marked "Jacobs Purple Label Extra" and "Mo-Max High Speed". I would have expected this Tool Steel to be provided in an annealed state (like drill rod) for machining but they all seem to be quite hard. It is very difficult if not impossible to cut with a hack saw blade.

Can someone please enlighten me?

 

[RJSakowski]

The generic term "tool steel" covers a wide range of alloys with a wide range of intended uses.

I don't know about the Jacobs brand but "Mo Max" is a brand name for HSS tool steel, the "Mo" presumably standing for molybdenum, a principle component in HHS. According to MSC, they sell both M2 and M42 HSS under the Mo Max brand so the branding alone wouldn't be sufficient in identifying the alloy.

I probably have fifty lbs. or more myself. They were drops collected by my ex for making blacksmithing tools and dies. Some pieces are marked but many are not which makes their usefulness questionable.

I have some tool steel catalogs squirreled away and I will try to dig them up.

 

[Alan H.]

I assume you are referring to HSS tool bits? I have some Mo-Max bits which are M2. Each company tends to have their own trademark and grades. You have to decipher what it is.

They are not "annealed". They come heat treated and ready to fly and because they are so hard, grinding them is a bit of a chore. There are many threads here on forum how to grind them. Here is a very good one.

Here is an example of a Cleveland Mo-Max bit:

 

[Silverbullet]

It would be very hard to figure out what steel you have tool bits as stated are hard some so hard there difficult to grind . There are file sets to gauge the hardness without the Rockwell hardness machine. Some of the tool bits if dropped will shatter like glass. Usually if a regular file will cut it you can machine it. As far as hardening after you can try either oil quench or air . I would guess a lot of it is A2 steel.

 

[lowpass5]

Thanks.
I think the pieces I received with my new machine are tool blanks, though much larger than what I am used to seeing. A couple are 1/2 x 1 x 8 inches, several 1 x 1 by 7 inch and one a little larger than that. Not sure what to do with these unless I can anneal them.

The pieces from my dad were used to build gun actions. They are still pretty hard but not like the stuff above. I think he used a lot of 4130 for the actions and mechanism parts.

 

[Bob Korves]

Yes, the hard ones are probably tool bit blanks. Cleveland M42 type tools are marked Mo-max Cobalt. The M2 tools are marked Mo-max only.

By the way, here is a good cross reference for tool steel from various manufacturers/sellers, Cleveland is unfortunately not included:
http://www.varcoprecision.com/tools.html

 

[benmychree]

Thanks.
I think the pieces I received with my new machine are tool blanks, though much larger than what I am used to seeing. A couple are 1/2 x 1 x 8 inches, several 1 x 1 by 7 inch and one a little larger than that. Not sure what to do with these unless I can anneal them.

The pieces from my dad were used to build gun actions. They are still pretty hard but not like the stuff above. I think he used a lot of 4130 for the actions and mechanism parts.

Forget trying to anneal the tool bits; they can be heated red hot without losing any significant hardness; it is an involved and very time consuming process to anneal high speed steel.

 

[f350ca]

I use large ones as you've listed for parallels on the milling machine vice. They're ground parallel enough for any work I do in a mill.

Greg

 

[T Bredehoft]

parallel enough for any work I do in a mill.

This too, speaks to 'tolerances." The work I do doesn't need four digit accuracy, generally I'm happy if I'm within .005 or so. Occasionally I'll file a turned piece to fit a hole I have already bored.

 

[joshua43214]

Keep your eye for Rex bits also. Some of the Rex bits rival carbide for wear resistance, but are tolerant of interrupted cuts. I use Rex bits in my fly cutters and pull light blue chips with no issue to the cutter. They are the right tool for cutting the grunge off of cast iron and hot rolled.