Technical guide

What does the code on your part drawing mean?

In the automotive industry, each OEM sets its own technical specifications to validate the corrosion resistance and thickness of metal coatings. If your component drawing calls for a specific designation, we perform in-house checks of thickness, adhesion and bath chemistry to ensure compliance.

Drawing notesRev. A

Coating per customer specification
Hexavalent chromium free
Minimum thickness as shown on drawing
Salt spray test per standard

Example of how the specification appears on a drawing

OEM

Below are the main specification families we work with at our plant:

Volkswagen specifications (VW TL standards)

VW TL

Designed to meet the requirements of the Volkswagen Group. These specifications cover both pure zinc finishes and high-performance alloys.

VW TL 217: Covers zinc and zinc-nickel coatings free of hexavalent chromium, defining corrosion protection requirements.
VW TL 244: Specifies zinc-nickel alloy coatings on steel parts, required for components exposed to engine-bay heat or road salt.

Common applications: Engine brackets, chassis fasteners, clamps and stamped structural components.

General Motors specifications (GMW standards)

GMW

Global GM standards that unify environmental resistance criteria across all vehicle platforms.

GMW 3044: Defines requirements for electroplated zinc coatings on iron and steel, setting the type of trivalent passivate and the required thicknesses.
GMW 4700: Specifies performance requirements for zinc-nickel alloy coatings, providing superior protection against red rust.

Common applications: Automotive fasteners, brake system components and powertrain parts.

Ford Motor Company specifications (WSS standards)

Ford WSS

Ford engineering standards that define the approved chemical processes for protecting components against rust.

WSS-M1P85: Covers electroplated zinc coatings applied in barrel or rack, with trivalent passivates free of hexavalent chromium.
WSS-M1P87: Sets the technical guidelines for zinc-nickel alloy deposits, ensuring resistance in mechanical assemblies.

Common applications: Fluid connections, fuel lines, lock nuts and hinges.

Nissan specifications (NES standards)

Nissan NES

Nissan Engineering Standards that define surface quality and durability requirements for chemical conversion and electroplating treatments.

NES M4040: Specifies requirements for electroplated zinc and its subsequent hexavalent-chromium-free passivation.
NES M4060: Defines process and resistance parameters for engineered zinc-nickel finishes.

Common applications: Suspension components, structural fasteners and internal engine hardware.

Quality

Quality control and validation

At Gycrom, every lot processed under these specifications goes through rigorous control:

Analytical monitoring
Continuous verification of the chemical parameters of our process tanks, using products from suppliers such as Atotech and Columbia Chemical.
In-house checks
Coating thickness measurement (8 to 15 microns, per specification) and in-house adhesion testing.
External validation
We coordinate sending samples to external laboratories for the salt spray corrosion test your specification requires.

Stellantis · BMW · Toyota

Does your drawing call for a different specification?

If your drawing includes variations or codes from other OEMs (such as Stellantis, BMW or Toyota), send us a digital copy of the drawing or its technical notes section. Our team will assess feasibility and offer a proposal that meets your requirement.

Send drawing for technical review Ask an engineer about a specification

References to OEMs are made for technical reference purposes only and do not imply affiliation, sponsorship or certification by those companies.