Geomet (Chrome-Free Zinc Flake, Eco Grade)
Geomet chrome-free zinc-flake coating: 500 h salt-spray protection with no hydrogen embrittlement risk, ideal for high-strength fasteners.
| Finish Code | TZ004 |
|---|---|
| Environmental Grade | Chrome-free zinc-flake system, RoHS and REACH compliant |
| Salt Spray Standard | 500 h; higher grades available on request |
| Appearance / Colour | Matt silver-grey |
| Suitable For | All types of screws and high-strength fasteners (10.9 / 12.9) |
| Features | Corrosion resistant; no hydrogen embrittlement |
| Environmental Compliance | Chrome-free system, 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 TZ004, salt spray 500 h; higher grades available on request, appearance / colour Matt silver-grey, environmental compliance Chrome-free system.
What sets this listing apart: Environmental Compliance Chrome-free system; Environmental Grade Chrome-free zinc-flake system.
Advantages
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.
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.
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 TZ004, Environmental Grade Chrome-free zinc-flake system, RoHS, Salt Spray Standard 500 h, Appearance / Colour Matt silver-grey.
How does it affect torque and friction?
Carbon Steel.
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.