EN ISO 10683 Fasteners – Non-electrolytically applied zinc flake coating systems
Basic Zinc Flake Coating Systems
1 only base coat
2 base coat + lubricant
3 base coat + top coat
4 base coat + top coat + lubricant
Standard Categories for Neutral Salt Spray Test
| Neutral salt spray test duration (without red rust) h | Reference thickness of the coating systema µm |
| 240 | 4 |
| 480 | 5 |
| 600 | 6 |
| 720 | 8 |
| 960 | 10 |
| a The reference thickness includes base coat(s) and top coat(s),), if any, with or without Cr(VI). The corrosion resistance shall be decisive for acceptance; the reference thickness is given for guidance only. The composition of the system (base coat only, base coat + top coat, etc.) shall be specified at the time of the order. | |
Designation of Zinc Flake Coating Systems for The Order
| Zinc flake coating system | Neutral salt spray test duration (red rust) | Torque/clamp force require- ment, if any | |||
| Base coat | Hexavalent chromium Cr(VI) | Organic or inor- ganic top coat | Additional lubricant, if any | ||
| Without integral lubricant = flZn or With integral lubricant = flZnL | No specification: may be delivered with or without Cr(VI) at the choice of the supplier or With Cr(VI) = yc or Without Cr(VI) = nc | With integral lubricant in the top coat = TL or Without integral lubricant in the top coat = Tn | L | e.g. 480 h | Ca |
| aRange of µ or K values to be specified at the time of the order | |||||
EN ISO 10683 Designation Examples:
EXAMPLE 1: Fastener with a non-electrolytically applied zinc flake coating (flZn), with a required minimum corrosion resistance (neutral salt spray test) of 240 h is designated as follows:
[fastener designation] – flZn/240h
EXAMPLE 2: Fastener with a non-electrolytically applied zinc flake coating with integral lubricant (flZnL), without Cr(VI) (nc), without top coat, with a required minimum corrosion resistance (neutral salt spray test) of 480 h, lubricated but without specific torque/clamp force requirement is designated as follows:
[fastener designation] – flZnL/nc/480h
EXAMPLE 3: Fastener with a non-electrolytically applied zinc flake coating (flZn) with Cr(VI) (yc), with a top coat with integral lubricant (TL), with a required minimum corrosion resistance (neutral salt spray test) of 720 h, and with a coefficient of friction µ within the range of [0,10 to 0,20] (C) is designated as follows:
[fastener designation] – flZn/yc/TL/720h/C
EXAMPLE 4: Fastener with a non-electrolytically applied zinc flake coating (flZn) without Cr(VI) (nc), without integral lubricant, with a top coat without integral lubricant (Tn), with additional lubricant (L), with a required minimum corrosion resistance (neutral salt spray test) of 960 h, and with a coefficient of friction µ equal to 0,17 ± 0,03 (C) is designated as follows:
[fastener designation] – flZn/nc/Tn/L/960h/C
Designation of Zinc Flake Coating Systems for Labelling
At least the following information shall be added on the label, separated by a slash (/):
— flZn for the zinc flake coating (base coat);
— yc for coating with Cr(VI), or nc for Cr(VI) free coating;
— minimum duration of corrosion resistance (neutral salt spray) in hours.
Examples 1 to 3 provide examples for labelling.
EXAMPLE 1 Hexagon head bolt ISO 4014 – M12×80 – 10.9 – flZn/nc/720h
EXAMPLE 2 Hexagon regular nut ISO 4032 – M12 – 10 – flZn/yc/480h
EXAMPLE 3 Plain washer ISO 7089 – 12 – 300HV – flZn/nc/240h
Typical zinc flake coating systems
Geometrical relationship between coating thickness and pitch diameter
| Coating thickness t | Pitch diameter increase 4ta |
| 3 | 12 |
| 4 | 16 |
| 5 | 20 |
| 6 | 24 |
| 8 | 32 |
| 10 | 40 |
| 12 | 48 |
| a This pitch diameter increase corresponds to the fundamental deviation (clearance), which is needed for the coating thickness t. | |