Plating Guidelines
ZINC PLUS CLEAR HEXAVALENT FREE CHROMATE – PART SUFFIX ZI
- Scope – This includes electrodeposited zinc coatings as applied to steel parts to protect them from corrosion. PEM FIN – C20 & C21 specifications are applicable.
PEM FIN-C20 (no bake) Specification – applies to product with a specified maximum hardness less than or equal to 1129 Mpa (HRC 35, 345.5HV) that does not require bake to relieve Hydrogen embrittlement.
PEM FIN-C21 (bake) Specification – applies to product with a specified maximum hardness greater than 1130 Mpa (HRC 35.1, 346.4HV) or have been case hardened, that requires bake to relieve Hydrogen embrittlement.
- Referenced Documents – Applicable sections of ASTM B633, ASTM F 1941, ASTM F1941M, ASTM F 1940, ASTM B850 & ASTM B117.
PEM FIN-C20 carries the following exception to ASTM B633 – section 6.5: Our material, processing and testing indicates that PEM® through hardened products (to a specified value of HRC 35 or less) do not require baking or heat treatment for hydrogen embrittlement relief. We therefore specify, Class ER-0 per ASTM B 850, Table 1 as appropriate for our product.
- Plating Thickness – The zinc plating shall be a minimum thickness of .0002 inch (5 µm) on all significant surfaces. Surfaces on which the specified thickness of deposit cannot readily be controlled, such as threads, holes, deep recesses, bases of angles, and similar areas, are exempt from the thickness requirements.
- Supplementary Finish – Parts shall have a clear hexavalent free chromate conversion coating applied.
- Testing – The parts shall be capable of passing 12 hour salt spray test per ASTM B117 with no white corrosion products. White corrosion products on external edges or corners shall not be cause for rejection.
Red corrosion products on surfaces which the specified thickness of deposit cannot readily be controlled, such as threads, holes, deep recesses, bases of angles, and similar areas, shall not be cause for rejection.
ZINC PLUS YELLOW HEXAVALENT FREE CHROMATE – PART SUFFIX ZC
- Scope – This specification covers electrodeposited zinc coatings as applied to steel, copper, brass, and bronze parts to protect them from corrosion.
PEM FIN – C26 & C27 specifications are applicable.
PEM FIN-C26 (no bake) Specification – applies to product with a specified maximum hardness less than or equal to 1129 Mpa (HRC 35, 345.5HV) that does not require bake to relieve Hydrogen embrittlement.
PEM FIN-C27 (bake) Specification – applies to product with a specified maximum hardness greater than 1130 Mpa (HRC 35.1, 346.4HV) or have been case hardened, that requires bake to relieve Hydrogen embrittlement.
- Referenced Documents – Applicable sections of ASTM B633, ASTM F 1941, ASTM F1941M, ASTM F 1940, ASTM B850 & ASTM B117.
PEM FIN-C26 carries the following exception to ASTM B633 – section 6.5: Our material, processing and testing indicates that PEM® through hardened products (to a specified value of HRC 35 or less) do not require baking or heat treatment for hydrogen embrittlement relief. We therefore specify, Class ER-0 per ASTM B 850, Table 1 as appropriate for our product.
- Plating Thickness – The zinc plating shall be a minimum thickness of .0002 inch (5 µm) on all significant surfaces. Surfaces on which the specified thickness of deposit cannot readily be controlled, such as threads, holes, deep recesses, bases of angles, and similar areas, are exempt from the thickness requirements.
- Supplementary Finish – Parts shall have an iridescent yellow hex-free chromate conversion coating applied. The parts shall have a yellow/gold color.
- Testing – The parts shall be capable of passing a salt spray test per ASTM B117. Minimum salt spray requirements are 96 hours with no white corrosion products and 120 hours with no red rust on significant surfaces.
White corrosion products on external edges or corners shall not be cause for rejection.
Red corrosion products on surfaces which the specified thickness of deposit cannot readily be controlled, such as threads, holes, deep recesses, bases of angles, and similar areas, shall not be cause for rejection.
ZINC PLUS CLEAR TRIVALENT CHROMATE PLUS SEALANT/LUBRICANT – PART SUFFIX LZ
- Scope – This specification covers electrodeposited zinc coatings as applied to steel parts to protect them from corrosion.
PEM FIN-C78P (no bake) Specification – applies to product with a specified maximum hardness less than or equal to 1129 Mpa (HRC 35, 345.5HV) that does not require bake to relieve Hydrogen embrittlement.
- Referenced Documents – Applicable sections of ASTM B633, ASTM F 1941, ASTM F1941M, ASTM F 1940, ASTM B850, ASTM B117, Ford Spec WX100, Ford Spec WZ100, SAE/USCAR -1, ISO 3613, GM 3034, Delphi DX900359
PEM FIN-C78P carries the following exception to ASTM B633 – section 6.5: Our material, processing and testing indicates that PEM® through hardened products (to a specified value of HRC 35 or less) do not require baking or heat treatment for hydrogen embrittlement relief. We therefore specify, Class ER-0 per ASTM B 850, Table 1 as appropriate for our product.
- Plating Thickness – The zinc plating shall be a minimum thickness of .0002 inch (5 µm) on all significant surfaces. Surfaces on which the specified thickness of deposit cannot readily be controlled, such as threads, holes, deep recesses, bases of angles, and similar areas, are exempt from the thickness requirements.
- Supplementary Finish – Parts shall have a trivalent chromate conversion coating applied and then leached back to a silver – white color with a combination leachant – sealant. The leachant – sealant shall have an integral lubricant.
- Testing – The parts shall be capable of passing a salt spray test per ASTM B117 or SAE/USCAR-1 after being baked at 120° C for 4 hours. Minimum times are 72 hours with no white corrosion products and 168 hours with no red corrosion products.
White corrosion products on external edges or corners shall not be cause for rejection.
Red corrosion products on surfaces which the specified thickness of deposit cannot readily be controlled, such as threads, holes, deep recesses, bases of angles, and similar areas, shall not be cause for rejection.
The parts shall be capable of passing the appropriate torque / clamping force requirements specified in Ford Spec WZ100 or as required by special customer specifications.
ZINC PLUS OTHER CHROMATE CONVERSION COATINGS
- Scope Other chromate conversion coatings such as black, blue and olive color are available on special order. These colored chromate coatings offer various degrees of corrosion resistance.
PennEngineering uses the detection methods defined in the IEC-62321-7-1:2015 to measure hexavalent chrome in the chromate conversion (passivation) layer of our zinc-chromate plated parts to assure they are not hexavalent chromium based as determined by IEC-62321-7-1:2015 and other consensus standards.
- Hazardous Substance Restrictions – Concentrations of lead, mercury, hexavalent chromium polybrominated biphenyls (PBB), and polybrominated diphenyl ethers (PBDE), in any as deposited homogenous material must be less than 1000 PPM or 0.1%. Additionally, the coating should contain less than 0.01 micrograms / cm2 of hexavalent chromium when tested per ISO 3613, or GM 3034, or Delphi DX900359 when based on the surface area per piece at nominal dimensions provided by PennEngineering.