Hard Chromed Components
(plated to salvage journals and increase useful life)
| Chrome is about the most
versatile plated metal in the industry. From the venerable ‘hard chrome’
to the famous ‘decorative chrome’, no other plated
metal has served so many needs for so many industries for so long. It is
virtually the nemesis of its metal rivals. When other metals are touted
for one thing or another, invariably there will be a comparison to chrome.
Chromium has excellent tarnish resistance, and the nickel undercoat in
decorative chrome (class 1) provides a good foundation for the lustrous
chromium finish. The nickel also provides corrosion protection for the
underlying steel. Another feature of chromium plating is that it resists
cleaning chemicals, handling and abrasive wear. |
Trans Case Decorative Chrome Plated
More extensive reading.
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Chrome |
[QQ-C-320B]
Excellent hardness (Rc 68-74), wear resistance
and erosion resistance. Has low coefficient of friction, and is resistant
to heat. In addition to above properties, can be rendered porous for lubrication
purposes. All coated steel parts having a hardness of Rockwell C 36 and
higher shall be baked after plating at minimum of 375 ± 25°F
per the following schedule: |
Rockwell
C36 Bake Schedule
| Tensile Strength
(Ksi) |
Time (At Temperature
Hours) |
| 160-180 |
3 |
| 181-220 |
8 |
| 221 and above |
12" |
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| All Class
2 plated parts designed for unlimited life under dynamic loads shall be
shot peened per MIL-S-13165 or MIL-R-81841 prior to plating.
Type I: Bright
Type II: Satin
Class 1: Decorative
Chrome; Corrosion protecting plating (.00001" minimum thickness on
all visible surfaces).
Class 2: Hard Chrome engineering
plating (.002 minimum thickness unless otherwise specified).
Class 2a: Plated to specified
dimensions or processed to specified dimensions after plating.
Class 2b: Parts below Rc 40
and subject to static loads or designed for limited life under dynamic
loads.
Class 2c: Parts below Rc 40
and designed for unlimited life under dynamic loads.
Class 2d: Parts have hardness
of Rc 40 or above and subject to static loads or designed for limited life
under dynamic loads.
Class 2e: Parts have hardness
of Rc 40 or above and are designed for unlimited life under dynamic loads.
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