ATP-641 Anti Scale Coating 07 February 2018 David ATP-641 is an anti scale coating manufactured in the USA to minimise scaling and pitting in heat treatment of our steels. This coating is water based and is able to be used on both oil quenching and air quenching steels. It has a working range of 1000F (537C) to 2400F (1315C). It is suitable to be used on all of our steels that we keep. The part needs to be clean and free of grease and oils etc before with painting, spraying or dipping the parts into the coating. Allow the coating to dry before commencing heat treatment and after quenching the coating will crumble off or can be washed off in water. We keep ATP-641 in pint (473ml) jars. For more information see the ATP-641 page on our webshop.