Where theworld gathers for metal finishing
Q&As since 1989
-----
Actual HRc hardness level of hard chrome plating
Q. It was mentioned in your Chrome Plating Tutorial that the hard chrome plating is usually applied to a "hardened" surface. Could you please tell me how hard the actual plating is and what the recommended min. hardness level (HRc) the steel should be to support it?
Joseph PleichnerDesign Engineer - Cleveland, Ohio, USA
2007
A. The substrate hardness is usually specified as 40 HRC minimum (390 HV minimum), but more typically ranges from 45-50 HRC (450-515 HV). Since the chromium plating is so thin (typically 15-25 micrometers) it cannot be directly tested using HRC, but it can be measured using Vickers microhardness and then converted to an approximate HRC number. Cr plating is usually a minimum of 900 HV (67 HRC), but is more typically around 1000-1100 HV. 940 HV is ~ 68 HRC which is the last data point in ASTM E140 or ISO 18265.
Toby PadfieldAutomotive module supplier - Michigan
2007
A. We commonly plated to 0.010 and you still use a Vickers or Knoop hardness. It does not exactly relate to HRC, but it is more than close enough for government work.
James Watts- Navarre, Florida
2007
A. Try this web-site:
http://www.efunda.com/units/hardness/show_hardness.cfm
Remember when converting between the various scales that each is only an approximation for the other.
Aerospace - Yeovil, Somerset, UK
2007
Q. What is the actual hardness of hard chromium plated ground steel rod.
Material: CK 45 / EN8D,
Chromium Thickness: 25 micron minimum on radius
Surface Roughness: Ra MAX. 0.2 micron
hydraulics - New Delhi, INDIA
July 15, 2013
Q, A, or Comment on THIS thread -or- Start a NEW Thread