ISO 4042 - Fasteners - Electroplated coatings

Electrodeposited coatings ISO 4042


coating thickness


Thickness in microns
The nominal coating thickness The actual thickness of the coating
Local a The average thickness of the batch B
least least greatest
3 3 3 5
5 5 4 6
8 8 7 10
10 10 9 12
12 12 11 15
15 15 14 18
20 20 18 23
25 25 23 28
30 30 27 35
a local thickness measurements, see 10.1
b measuring the average thickness in the batch, see 10.2.

Area for local measurement of coating thickness for the components



The upper limits of coating thickness ISO metric threads

Pitch P mm Nominal thread diameter Internal thread External thread
Tolerance position G Tolerance position g External thread tolerance position f Tolerance position c
For thread with coarse pitch d mm a Basic deviation The maximum thickness of the coating Basic deviation The maximum thickness of the coating Basic deviation The maximum thickness of the coating Basic deviation The maximum thickness of the coating
b c b c b c
All nominal lengths Nominal length l All nominal lengths Nominal length l All nominal lengths Nominal length l
µm µm µm µm l≤5d
µm
5d<l≤10d
µm
10d<l≤15d
µm
µm µm l≤5d
µm
5d<l≤10d
µm
10d<l≤15d
µm
µm µm l≤5dµm 5d<l≤10d
µm
10d<l≤15d
µm
02 +17 3 -17 3 3 3 3
0,25 1; 1,2 +18 3 -18 3 3 3 3
0.3 1.4 + 18 3 -18 3 3 3 3
0,35 1,6
(1,8)
+19 3 -19 3 3 3 3 -34 8 8 5 5
0,4 2 +19 3 -19 3 3 3 3 -34 8 8 5 5
0,45 2,5 (2,2) +20 5 -20 5 5 3 3 -35 8 8 5 5
0.5 3 +20 5 -20 5 5 3 3 -36 S 8 5 5 -50 12 12 10 8
0,6 3,5 +21 5 -21 5 5 3 3 -36 8 8 5 5 -53 12 12 10 8
0,7 4 +22 5 -22 5 5 3 3 -38 8 8 5 5 -56 12 12 10 8
0.75 4,5 +22 5 -22 5 5 3 3 -38 8 8 5 5 -56 12 12 10 8
O.S 5 +24 5 -24 5 5 3 3 -38 8 8 5 5 -60 15 15 12 10
i 6(7) +26 5 -26 5 5 3 3 -40 10 10 8 5 -60 15 15 12 10
1,25 8 +28 5 -28 5 5 5 3 -42 10 10 8 5 -63 15 15 12 10
1,5 10 +32 8 -32 8 8 5 5 -45 10 10 8 5 -67 15 15 12 10
1,75 12 +34 8 -34 8 8 5 5 -48 12 12 8 8 -71 15 15 12 10
2 16(14) +38 8 -58 8 8 3 5 -52 12 12 10 8 -71 15 15 12 10
2,5 20 +42 10 -42 10 10 8 5 -58 12 12 10 8 -80 20 20 15 12
(18; 22)
3 24 (27) +48 12 -48 12 12 8 8 -63 15 15 12 10 -85 20 20 15 12
3,5 30
(33)
+53 12 -53 12 12 10 8 -70 15 15 12 10 -90 20 20 15 15
4 36 (39) +60 15 -60 15 15 12 10 -75 15 15 15 12 -95 20 20 15 15
4,5 42 (45) +63 15 -63 15 15 12 10 -80 20 20 15 12 -100 25 25 20 15
5 48
(52)
+71 15 -71 15 15 12 11) -85 20 20 15 12 -106 25 25 20 15
5,5 56 (60) +75 15 -75 15 15 15 12 -90 20 20 15 15 -112 25 25 20 15
6 64 +80 20 -80 20 20 15 12 -95 20 20 15 15 -118 25 25 20 15

a Information about the thread pitch with Limbo is only complementary. A crucial figure is the thread pitch.

b The maximum thickness of the coating just assuming agreement on measurement of the local thickness.

c The maximum thickness of the coating, only if an agreement on measuring the average thickness of the lot.



The corrosion resistance of zinc and cadmium coatings neutral salt spray.

Code marking coatings and (B system b) The nominal coating thickness pm Designation chromate treatment c Beginning formation of white rust The beginning of the formation of red rust
hours Kadmium hours Zinc hours
Fe/Zn or Fe/Cd 3c1A 3d A 2 24 12
Fe/Zn or Fe/Cd 3c1 B B 6 24 12
Fe/Zn or Fe/Cd 3c2C C 24 36 24
Fe/Zn or Fe/Cd 3c2D D 24 36 24
Fe/Zn nebo Fe/Cd 5c1A 5 A 6 48 24
Fe/Zn or Fe/Cd 5c1 B B 12 72 36
Fe/Zn or Fe/Cd 5c2C C 48 120 72
Fe/Zn or Fe/Cd 5c2D D 72 168 96
Fe/Zn or Fe/Cd 5Bk Bk 12 - -
Fe/Zn or Fe/Cd 8c1A 8 A 6 96 48
Fe/Zn or Fe/Cd 8c1B B 24 120 72
Fe/Zn or Fe/Cd 8c2C C 72 168 120
Fe/Zn or Fe/Cd 8c2D D 96 192 144
Fe/Zn´or Fe/Cd 8Bk Bk 24 120 72
Fe/Zn or Fe/Cd 12c1A 12 A 6 144 72
Fe/Zn or Fe/Cd 12c1B B 24 192 96
Fe/Zn or Fe/Cd 12c2C C 72 240 144
Fe/Zn or Fe/Cd 12c2D D 96 264 168
Fe/Zn or Fe/Cd 12Bk Bk 24 192 96
Fe/Zn or Fe/Cd 25c1A 25 A Data not available
Fe/Zn or Fe/Cd 25c1 B B
Fe/Zn or Fe/Cd 25c2C C
Fe/Zn or Fe/Cd 25c2D D
Fe/Zn or Fe/Cd 25Bk Bk


designation chromate

Class designation type typical appearance Corrosion Protection
1 A limpid Distinctive, clear, sometimes with a bluish tint Low, mainly against staining during the processing or against high humidity at moderate corrosion conditions
B pale Distinctive, slightly iridescent
2 C Iridescent yellow vibrant High, including protection against certain organic vapors
D opaque Olive green with the transition to brown or bronze
Bk a Black Black, slightly iridescent Varying degrees of protection against corrosion

a Coatings types A to D can be complemented with a black coating.



The corrosion resistance of nickel and nickel / chrome coatings salt fog

Code label and coating (system Bb) The beginning of the formation of red rust on visible (important) surface
The substrate of copper or copper alloys Substrate ferrous materials Corrosion test neutral salt spray (NSS)e Accelerated corrosion test acidified salt spray (CASS)
Nickel c Nickel+chrom c d Nickel c + Nickel chrome or copper + nickel + chrome c,d
Cu/Ni 3b Cu/Ni
3b Cr r
Fe/Ni
5b
Fe/Ni
5b Cr
- -f
Cu/Ni 5b Cu/Ni
5b Cr r
Fe/Ni
10b
Fe/Ni 10b Cr Fe/Cu 10 Ni 5b Cr r 12h -f
Cu/Ni 10b Cu/Ni
10b Cr r
Fe/Ni
20b
Fe/Ni 20b Cr Fe/Cu 20 Ni 10b Cr r 48h -f
Cu/Ni 20b Cu/Ni
20b Cr r
Fe/Ni
30b
Fe/Ni
30b Cr
- 8h
not recommended Cu/Ni 30d Cr r not recommended Fe/Ni 40d Cr - 16h

a Classification codes nickel deposits refer to ISO 1456: 1988.

b Coding systems labeling see chapter 13th

c "B" refers to the gloss nickel coatings and "d" "on the duplex nickel coatings.

d "R" "refers to conventional thicknesses of chromium on the minimum thickness of 0.3 pm.

e Corrosion tests neutral salt spray (NSS) are not usually intended for Ni / Cr coatings.

f Duration of accelerated corrosion tests acidified salt spray (CASS) for lower grades coatings would be too short to be meaningful.



Metal / alloy coating

Metal / alloy coating designation
Brand Element
Zn Zinc A
Cd b Cadmium B
Cu Copper C
CuZn brass D
Ni b nickel E
NibCrrb Nickel-chromium F
CuNi bb Copper-nickel G
CuNi b Cr rb Copper-nickel-chrome
0
H
Sn tin J
CuSn Copper-tin (bronze) K
Ag silver L
CuAg Copper-silver N
ZnNi Zinc-nickel P
ZnCo Zinc-cobalt Q
ZnFe Zinc-iron R

a The use of cadmium in certain countries restricted or prohibited.

b Classification codes see ISO 1456

c The thickness of chromium is about 0.3 pm.



The coating thickness (total thickness of the coating)

The coating thickness pm designation
one metal coating two metal coating a
coating thickness is determined - 0
3 - 1
5 2+3 2
8 3+5 3
10 4+6 9
12 4+8 4
15 5+10 5
20 8+12 6
25 10+15 7
30 12+18 8

a The thicknesses for the first and second metal coating are applicable to all combinations except where chromium whose thickness is always 0.3 pm, the topsheet.



The surface appearance and chromate

surface Appearance Chromate passivation characteristic color designation
matte colorless A
bluish to rainbow b B
yellow to yellow-brown, iridescent C
olive green to olive brown D
Semi-gloss colorless E
bluish to rainbow b F
yellow to yellow-brown, iridescent G
olive green to olive brown H
shiny colorless J
bluish to rainbow b K
yellow to yellow-brown, iridescent L
olive green to olive brown M
The high-gloss colorless N
arbitrary as B, C or D P
matte brown-black to black R
Semi brown-black to black S
shiny brown-black to black T
The high-gloss without modification chromatec U

a Edit passivation are only possible on zinc or cadmium coating

b Applicable only for zinc coating

c An example of this coating is: A5U