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Lubricity And Rust Protection For Sprockets, Universal Joints And PT Components Provided by Tru Temp® Finish

Tru TempSprockets, universal joints, sheaves and power transmission components take on a protective and attractive black oxide finish when treated with Tru Temp® low temperature, non-polluting black oxide from Birchwood Technologies Metal Finishes.

The Tru Temp process adds lubricity as well as a non-dimensional, deep black finish with long-term corrosion resistance – the ideal finish for all types of power transmission components. Without changing threaded holes or critical dimensions, the Tru Temp finish affords protection from galling and corrosion, without impairing fit and function, even in tight tolerance assemblies. At the same time, the Tru Temp finish enhances overall quality and sales appeal, thereby allowing critical components to be marketed as premium grade products that command higher selling prices than un-blackened, or standard grade, components.

The satin black magnetite coating is just 0.5 microns thick (20 millionths) with no effect on material hardness or tensile strength. The finish withstands up to 100-200 hours of neutral salt spray (ASTM B 117) or several hundred hours of humidity (ASTM D 1748), verified by independent testing. This high level of corrosion protection is important for both part storage and shipment in corrosive atmospheres including ocean shipment.

Conventional 290°F hot oxide processes have a tendency for splattering and boilover, making them very hazardous to operate. On the other hand, commonly used phosphate processes operate at 180-200°F, but often cause hydrogen embrittlement of the steel due to extended contact with acidic process baths that tend to etch the steel. By contrast, the Tru Temp solution operates at only 200°F and uses mild alkaline chemistry that does not embrittle the steel. Consequently, the Tru Temp system is a very safe and effective option for high quality, in-house black oxiding that improves quality with a short turnaround time.

Total processing time is just 25 minutes and operating cost (including chemical and heating cost) averages just $0.01 to 0.03 per pound of finished work. Small parts can be processed in bulk loads or larger parts finished on racks. Most existing tank lines can be retrofitted for Tru Temp at low cost. New process lines are available at modest cost from Birchwood Technologies. The process can be automated, at low cost, through the use of a CNC programmable hoist system.

In addition, the Tru Temp solutions contain no EPA regulated chemicals, so there is usually no need for waste treatment equipment. In most areas, the rinse waters are sewerable as non-hazardous discharge. This benefit simplifies the installation and minimizes the capital investment needed to set up the process line.


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