ASTM F1136
Standard Specification for Zinc/Aluminum Corrosion Protective Coatings for Fasteners
Formerly specified water-based zinc/aluminum dispersion coatings and optional sealers or topcoats for ferrous fasteners.
Successor: ASTM F3393. New drawings should cite the successor; existing call-outs to ASTM F1136 remain understood.
What ASTM F1136 specifies
ASTM F1136/F1136M classified dip-spin, dip-drain, or spray-applied zinc/aluminum fastener coatings into six grades. Grades 1–6 used average thickness ranges of 4–5, 5–8, 6–12, 8–15, 6–12, and 8–15 µm, with different sealers, topcoats, and salt-spray requirements. Grade 5 included a lubricated sealer; Grade 6 used a pigmented topcoat. ASTM withdrew the document in 2025 and replaced it with ASTM F3393, so new designs should use the replacement. Legacy procurement must still state grade, chrome or non-chrome system, color, friction requirement, and thread-fit acceptance.
ASTM F1136 types and classes
Every designation the document defines, with the thickness it requires and the tests it imposes.
| Designation | Meaning | Thickness | Coating weight | Requirement / test |
|---|---|---|---|---|
Grade 1 | Basecoat only. | 4–5 µm 0.16–0.2 mil | 16–20 g/m² average. | 240 h salt spray for chromium-containing system. |
Grade 2 | Heavier basecoat only. | 5–8 µm 0.2–0.31 mil | 20–28 g/m² average. | 500 h C or 240 h NC salt spray. |
Grade 3 | Basecoat plus clear sealer. | 6–12 µm 0.24–0.47 mil | 22–34 g/m² average. | 1000 h C or 720 h NC salt spray. |
Grade 4 | Heavy basecoat only. | 8–15 µm 0.31–0.59 mil | 28–50 g/m² average. | 1000 h C or 500 h NC salt spray. |
Grade 5 | Basecoat plus lubricated sealer. | 6–12 µm 0.24–0.47 mil | 22–34 g/m² average. | 1000 h C or 720 h NC salt spray. |
Grade 6 | Basecoat plus pigmented topcoat. | 8–15 µm 0.31–0.59 mil | 23–40 g/m² average. | 500 h C or 500 h NC salt spray. |
Tests and the drawing call-out
Tests the document imposes
- Coating thickness and mass
- ASTM B117 salt spray
- Tape adhesion with less than 5% removal
- Blister resistance
- GO-gage thread fit
- Hydrogen-embrittlement process controls
How to cite it
Drawing call-out
ZINC/ALUMINUM FLAKE COATING PER LEGACY ASTM F1136, GRADE <1–6>, <C|NC>, <COLOR>, <FRICTION>; USE ASTM F3393 FOR NEW DESIGNAngle brackets mark the choices the drawing must make; every finish page shows a completed example.
Finishes specified to ASTM F1136
ASTM F1136 — frequently asked
Is ASTM F1136 still active?
No. ASTM withdrew it in 2025 and replaced it with ASTM F3393. Keep F1136 only for controlled legacy drawings.
Which grade includes controlled lubricity?
Grade 5 uses a lubricated sealer. The required torque-tension or friction range still needs to be stated.
Does zinc flake avoid hydrogen embrittlement?
The coating application is non-electrolytic, but acid or phosphate pretreatment can still introduce hydrogen. The process route must be controlled for high-strength fasteners.
ASTM F1136 is copyrighted by ASTM International. This page explains the document so a drawing can be read; it does not reproduce the standard. Purchase the current edition from the publisher. Official source ↗