There is a small fee for samples shipped in the continental U.S. This can range from $10-$75. Products shipped outside the continental U.S. can be subject to certain restrictions. Freight charges may range from $75-$300.


KOOL-BLAK 225 is a chemical solution which converts the surface of ferrous metals to black iron oxide - Fe3O4 magnetite. The black oxide penetrates the surface, becomes an integral part of the surface and provides for protection of the surfaces. Blackened parts retain their surface properties and dimensions.

KOOL-BLAK 225 is a highly concentrated solution of EPi’s oxidizing salt formulation (patent pending) containing a blend of activators, rectifiers, catalysts, penetrants and wetters.  The KOOL-BLAK 225 finish meets military specification MIL-DTL-13924D Class 1 as well as Aerospace Material Specification AMS 2485H.

Review information on our KOOL-BLAK 225 Short Run Production Kit for smaller jobs, to complete and Order Form or to place an Online ORDER.

The KOOL-BLAK 225 solution is operated at a temperature of 220-240°F to blacken a wide range of carbon steels, alloy steels and hardened tool steels.  It will not blacken stainless steels.  Passes the oxalic acid test and produces no smut like other processes.  Eliminate boiling caustic fumes, provide safer work environment and save energy costs ($$).

View EPi's "How To Use KOOL-BLAK 225" Video