Zinc-Aluminium Coating (Zinc Flake / Chrome-Free Series)
Zinc-aluminium flake coating: 500 h+ salt-spray protection with a chrome-free, conductive, metallic finish.
| Finish Code | TZ327 |
|---|---|
| Environmental Grade | Chrome-free, REACH / RoHS compliant |
| Salt Spray Standard | 500 h and above |
| Appearance / Colour | Metallic silver-grey |
| Suitable For | All types of screws, fasteners and precision metal parts |
| Features | Corrosion resistant; conductive; no hydrogen embrittlement |
| Environmental Compliance | Chrome-free, REACH and RoHS compliant |
Overview
Surface finishing on a fastener is a functional coating, not a cosmetic one: it sets the friction coefficient that determines how much of the applied torque becomes clamp load, and it defines how long the part survives in a corrosive environment. Two finishes that look identical can differ by a factor of several in salt-spray hours and by enough in friction to change the torque specification. This listing: finish code TZ327, salt spray 500 h and above, appearance / colour Metallic silver-grey, environmental compliance Chrome-free, REACH and RoHS compliant.
What sets this listing apart: Environmental Grade Chrome-free, REACH / RoHS compliant; Features Corrosion resistant.
Advantages
Friction coefficient changes with coating: a zinc-flake coating typically runs lower and more consistently than electroplated zinc, which is why torque tables are finish-specific.
Barrier coatings protect the base metal, while sacrificial coatings protect the steel even at a scratch; the choice depends on whether the joint will be damaged in service.
Hydrogen embrittlement risk separates processes: electroplating on high-strength steel needs a de-embrittlement bake, while mechanical and flake coatings avoid the risk entirely.
Applications
Automotive underhood and body joints, outdoor equipment, marine and coastal installations, electronics hardware, and any joint where the torque specification is tied to a friction value.
Quote the standard, the hours and the acceptance criterion together — a salt-spray figure without the test method is not a specification. Check that the coating process is compatible with the core hardness of the part.
Product information is supplied by Toprecision. Custom parts can be produced to drawing — contact us for samples or a quotation.
Specifications across this series
2 parts in this series
| Part | Finish Code | Environmental Gr… | Salt Spray Stand… | Appearance / Col… |
|---|---|---|---|---|
| Geomet (Chrome-Free Zinc Flake, Eco Grade) · TZ004 / Chrome-free zinc-flake system, RoHS and REACH compliant / 500 h; higher grades available on request | TZ004 | Chrome-free zinc-flake system, RoHS and REACH compliant | 500 h; higher grades available on request | Matt silver-grey |
| Zinc-Aluminium Coating (Zinc Flake / Chrome-Free Series) · TZ327 / Chrome-free, REACH / RoHS compliant / 500 h and above | TZ327 | Chrome-free, REACH / RoHS compliant | 500 h and above | Metallic silver-grey |
Values are taken from each part’s own attribute set. Changing length, material or finish changes pull-out strength and installation torque, so compare the row that matches your drawing.
Selection and test data: engagement length, standards, salt-spray hours
FAQ
What does this finish provide?
Finish Code TZ327, Environmental Grade Chrome-free, REACH / RoHS compliant, Salt Spray Standard 500 h and above, Appearance / Colour Metallic silver-grey.
How does it affect torque and friction?
Aluminium Alloy.
What should I verify before ordering or installing it?
Quote the standard, the hours and the acceptance criterion together — a salt-spray figure without the test method is not a specification. Check that the coating process is compatible with the core hardness of the part.