Pentrate Ultra Brochure

The Industry Standard for Black Oxide Coatings

BLACK, BLACKER, BLACKEST. Heatbath® is proud to offer Pentrate® Ultra, the latest development in the field of black oxide finishing. As creators of the Pentrate process, it is our quest to continually lead the way in the advancement of new and innovative Pentrate products. Pentrate Ultra is revolutionary in its ability to achieve the blackest possible finish on steel attainable in the industry today. Our claim “It doesn’t get any BLACKER than this” has been substantiated by our research and development laboratories after extensive tests were conducted using state-of-the-art optics.

Pentrate Ultra has many features and benefits in addition to its superior blackening powers…it offers faster, more efficient blackening, increased corrosion protection, excellent abrasion resistance, improved appearance and lower operating costs than other black oxide processes.


  • Deep Black – No Rub Off The powerful inhibitor contained in Pentrate Ultra controls the build up of colloidal iron in the bath, eliminating the possibility of superficial red, brown or green films forming on the surface of steel parts. With Pentrate Ultra, the steel being processed comes out uniformly black the first time…every time.
  • Contains an Improved Rectifier By incorporating a rectifier in Pentrate Ultra, contamination from nonferrous metals such as copper, zinc or lead is no longer a problem. The rectifier reacts with these nonferrous metals right in the bath, eliminating pink or red discoloration. It also helps color copper brazed and silver soldered joints to blend in with the black oxide finish.
  • Wetting Agent Reduces Dragout Operating baths are more fluid and have lower surface tension thanks to a unique wetting agent that is part of the Pentrate Ultra chemistry. This results in less drag out – More Pentrate Ultra stays in the tank! This ultimately saves the user time by eliminating the need to frequently replenish the bath. This also saves money by reducing the amount of chemical needed for processing, while at the same time lowering waste treatment costs.
  • No Dimensional Change Pentrate Ultra literally penetrates the surface of the steel being treated without altering dimensions or physical properties of the steel. The only difference in the work after it is processed is its durable, lustrous black oxide finish.
  • Simple, Inexpensive Bath Operation Only 6 pounds of salt are required per gallon for normal operating temperature of 285-290ºF. One chemically balanced salt is used in one solution to produce a superior black oxide finish. Of course, Pentrate Ultra is also available in liquid form for automatic feed pump systems.
  • Exceeds Requirements of Military Specifications The Pentrate Ultra Black Oxide finish meets or exceeds all government specifications for black oxide on steel, including MIL-DTL-13924 and AMS 2485. When using Pentrate Ultra there is no problem in passing the salt spray requirements or oxalic acid test contained in these specifications.

For a copy of our Pentrate Ultra Brochure – a detailed overview of the black oxide process…Contact us.

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