product data


Black Oxide

What is the TruTemp® Black Oxide System?

Utilizing a unique two-stage oxidation (patent pending), the TruTemp® process forms a black magnetite finish on all iron and non-stainless steel parts. The TruTemp® process operates effectively at much lower temperatures than ordinary black oxide- 100 degrees lower, in fact! The result is a protective black finish-.000020" (1 micron) thick, with an attractive satin black appearance equal to that of regular black oxide.

Safe. Easy to Operate. No Boiling Chemicals
Let's face it. The 290°F operation of ordinary black oxide is scary hazardous! The typical bath contains 6-8 pounds of caustic soda per gallon, and is prone to boil-over and splattering. This creates a worker safety nightmare! By comparison, the TruTemp® bath is much milder and cooler -- severe hazards arejust not present.

Fast. Cost Effective Process
The TruTemp® blackening reaction takes only 6-15 minutes, compared with 20-40 minutes for ordinary hot oxide. As a result, the entire process is shorter and the work flows through faster, resulting in lower labor costs. Since labor is the largest single cost factor of any blackening system, your overall finishing costs are reduced significantly.

No EPA Regulated Chemicals
The TruTemp® system contains no heavy metals, carcinogens or other EPA regulated materials. The rinse water effluent from the process line is generally sewerable, usually with pH adjustment only. (Check with your local authorities)

A Whole New Optionfor Parts Finishing
If you now own a black oxide system, or send parts outside for blackening, theTru Temp in-house blackening system provides a better option for you. You canregain control of your black finishing, without endangering your employees orcompromising the quality of the black finishes. The process meshes easily withyour Quality and Inventory systems by giving you control over the quality,scheduling and cost of your finishing operation.

High Quality Black Finishes without Salt Bloom!

An ordinary hot oxide bath is very viscous and difficult to rinse off. Blind holes and recessed areas often form white salt blooms which destroy the value of the finished part and upset customers! Because the TruTemp® solution is much milder and cooler, it rinses freely. White salt blooms are a thing of the past! Castings and powdered metals turn out a rich black. Note that the TruTemp® black finish complies with MIL-C-13924C, Class 1 and is corrosion resistant. It withstands 100-300 hours salt spray, depending on the sealant used. TruTemp™Examples   

JSA sales and service representatives train customers on the proper uses and treatment of these chemicals.  JSA stocks Birchwood products locally in the Midwest and provides the immediate in-house service that will help maintain production and efficiently troubleshoot issues.  Please click here to help us learn about your application so we can promptly and effectively respond to your needs. 

Compare Tru Temp to Ordinary Hot Oxide


Tru Temp®

Ordinary Hot Oxide

Finish Quality

Durable, Satin Black Magnetite

Durable, Satin Black Magnetite


.000020" Thick

.000020" Thick


Mil Spec Compliant

Mil Spec Compliant


No Salt Bloom

Salt Bloom Common

Process Line

190° F Bath, 12-18 min process

290° F Bath, 15-50 min process


No Splatter or Boilover

Constant Boilover Hazards


No Sludging

Heavy Sludging


All non-stainless steels

Most steels (Some Turn Red)


Cast Irons

No Cast Irons (Turn Red)


Powdered Metal

No Powdered Metal (Salt Bloom)

Corporate Concerns

No EPA Regulated Materials

No EPA Regulated Materials


Safe to operate

Scary Process


Operator Friendly

Operators Hate It!

Tru Temp - High QualityBlack Finish Without Salt Bloom