Tool Steel

Tool steel selection depends on life expectancy required, application, if coatings are going to be applied, cost, and heat treating facilities available.

The most common tool steel is O1 because it easily heat treated with a torch, cost is reasonable, and is available as flat stock and drill rod.

Chrome moly grades 4140 and 4340 are also used as tool steel because of cost.

Other common tool steels are A2, D2, P20, and 440 stainless all of which are very expensive.

Check out steel options in a Machinery Handbook and search tool steel distributors websites for steel definitions and applications.

There is no "best" tool steel for die work. There are many considerations. Each "flavor" of tool steel has its advantages and limitations. Dies often require different steels for different components. The selection of the steel for a particular die is one of the arts of die making and much is only learned from experience.

• Cost: not the cost to buy the steel, this is trivial compared the cost to build and maintain the tool. The real issue is the cost to machine and heat treat. and finish the components.
• Production expectations. Is this a short run, one time tool, or is the die intended to run millions of parts per year?
• Material to be stamped. For example, high Chrome, high carbon die steels (D2) stainless steel does not do well with high chrome alloys such as stainless steel.
• Do you want to use a PVD coating. Then you need to use a high speed steel such as M2

A good starting point would be A2. Then consider why not. Do you need better wear resistance and longer production between sharpening? Then D2 or perhaps one of the PM steels such as CPM10V. Both are difficult to machine and grind. CPM10V is expensive to heat treat. For slender and delicate punches M2 is indicated. Of course, if cost is not a consideration, then go with Tungsten Carbide.

The most common one i heard for that application is called "special k steels" 1% up to 2% carbon.I never heard like uphere .45% C.Some hard alloys are more commonly used in cutting purposes.Just google on for trademarks.-

"special K", KNL and M2 are more or less the same animal.

Note the previous post about 'what flavor' - this is also asking "what are you punching?"

Until that is known - all suggestions are useless.

Right.-