Dimensions mm · values as the standard states them Size P s e k c r t dc dp drilling_range_max drilling_range_min f k´ ST3.5 5.5
5.32 – 5.5
≥ 5.96
3.2 – 3.45
≥ 0.6
≤ 0.5
1 – 1.4
7.6 – 8.3
≤ 2.8
2.25
0.7
≈ 0.4
≥ 1.55
(ST3.9) 5.5
5.32 – 5.5
≥ 5.96
3.2 – 3.45
≥ 0.6
≤ 0.5
1 – 1.4
7.6 – 8.3
≤ 3.1
2.4
0.7
≈ 0.4
≥ 1.55
ST4.2 7
6.78 – 7
≥ 7.59
4 – 4.25
≥ 0.9
≤ 0.6
1.2 – 1.6
8.2 – 8.8
≤ 3.6
3
1.75
≈ 0.4
≥ 1.9
ST4.8 8
7.78 – 8
≥ 8.71
4.15 – 4.45
≥ 0.9
≤ 0.7
1.4 – 1.8
9.8 – 10.5
≤ 4.1
4.4
1.75
≈ 0.5
≥ 2
ST5.5 8
7.78 – 8
≥ 8.71
5.15 – 5.45
≥ 1
≤ 0.8
1.6 – 2
10 – 11
≤ 4.8
5.25
1.75
≈ 0.5
≥ 2.7
ST6.3 10
9.78 – 10
≥ 10.95
6.15 – 6.45
≥ 1
≤ 0.9
1.8 – 2.2
12.2 – 13.2
≤ 5.8
6
2
≈ 0.5
≥ 3.3
Ranges read min – max; ≤ / ≥ where the standard gives one limit, ≈ for approximate values. Sizes in (brackets) are non-preferred. Select a row for its size sheet.
Length tolerances 9.5 8.75 – 10.25
13 12.1 – 13.9
16 15.1 – 16.9
19 18 – 20
22 21 – 23
25 24 – 26
32 30.75 – 33.25
38 36.75 – 39.25
45 43.75 – 46.25
50 48.75 – 51.25
Size sheet · DIN 7504 K
ST3.5
s width across flats 5.5
e width across corners ≥ 5.96
k head height 3.2 – 3.45
c ≥ 0.6
r fillet radius ≤ 0.5
t 1 – 1.4
dc 7.6 – 8.3
dp ≤ 2.8
drilling_range_max 2.25
drilling_range_min 0.7
f ≈ 0.4
k´ ≥ 1.55 Standard lengths
9.5 · 13 · 16 · 19 · 22 · 25
Size sheet · DIN 7504 K
ST3.9
s width across flats 5.5
e width across corners ≥ 5.96
k head height 3.2 – 3.45
c ≥ 0.6
r fillet radius ≤ 0.5
t 1 – 1.4
dc 7.6 – 8.3
dp ≤ 3.1
drilling_range_max 2.4
drilling_range_min 0.7
f ≈ 0.4
k´ ≥ 1.55 Standard lengths
13 · 16 · 19 · 22 · 25 · 32 · 38
Size sheet · DIN 7504 K
ST4.2
s width across flats 7
e width across corners ≥ 7.59
k head height 4 – 4.25
c ≥ 0.9
r fillet radius ≤ 0.6
t 1.2 – 1.6
dc 8.2 – 8.8
dp ≤ 3.6
drilling_range_max 3
drilling_range_min 1.75
f ≈ 0.4
k´ ≥ 1.9 Standard lengths
13 · 16 · 19 · 22 · 25 · 32 · 38
Size sheet · DIN 7504 K
ST4.8
s width across flats 8
e width across corners ≥ 8.71
k head height 4.15 – 4.45
c ≥ 0.9
r fillet radius ≤ 0.7
t 1.4 – 1.8
dc 9.8 – 10.5
dp ≤ 4.1
drilling_range_max 4.4
drilling_range_min 1.75
f ≈ 0.5
k´ ≥ 2 Standard lengths
13 · 16 · 19 · 22 · 25 · 32 · 38 · 45 · 50
Size sheet · DIN 7504 K
ST5.5
s width across flats 8
e width across corners ≥ 8.71
k head height 5.15 – 5.45
c ≥ 1
r fillet radius ≤ 0.8
t 1.6 – 2
dc 10 – 11
dp ≤ 4.8
drilling_range_max 5.25
drilling_range_min 1.75
f ≈ 0.5
k´ ≥ 2.7 Standard lengths
16 · 19 · 22 · 25 · 32 · 38 · 45 · 50
Size sheet · DIN 7504 K
ST6.3
s width across flats 10
e width across corners ≥ 10.95
k head height 6.15 – 6.45
c ≥ 1
r fillet radius ≤ 0.9
t 1.8 – 2.2
dc 12.2 – 13.2
dp ≤ 5.8
drilling_range_max 6
drilling_range_min 2
f ≈ 0.5
k´ ≥ 3.3 Standard lengths
19 · 22 · 25 · 32 · 38 · 45 · 50
Provenance
Draft — values taken from a single source and not yet cross-checked.
fasteners.eu dimensions, lengths, materials, property classes, current norm, equivalent norms Otto Roth status Accessed 2026-09-23 · For design and safety-critical use, consult the current edition of the standard.