Room-temperature blackening (65° to 85° F), also referred to as cold blackening, is a preferred low cost in-house blackening process due to safe operation. It offers an excellent way to achieve good corrosion protection and enhance sales appeal. The porous crystalline structure of the black finish has a uniform 0.000030 inch (1 micron) thickness.
Products: Presto Black
Mid-temperature black oxide (200° to 210° F) operates at substantially lower temperature than traditional hot black oxide (temp 285-290° F) with a comparable finish. It has become an ideal replacement for hot oxide due to safer operation and lower heating costs. Forms a black magnetite (Fe3O4) finish on all iron and steel parts, not including stainless steel.
Products: Tru Temp
Hot-temperature black oxide (285° to 290° F) operates at the highest temperature of all conventional black oxides. This is a conversion coating formed by a chemical reaction produced by the alkaline salt solution and the immersion of the metal parts. This process is usually performed only by highly trained metal finishing companies. Closely monitored chemical balance is required to prevent salt bloom and discolored red-black coatings. Water balance and proper controls are required to prevent steam explosion.
Products: Birchwood Technologies does not manufacture a hot oxide at this time. We developed our mid-temperature black oxide as a safer replacement to the extreme operating temperatures for hot oxide.