Dimensions mm · values as the standard states them Type C Type F
Size P dk k a t A hexalobular f recess_no hexalobular y y ST2.9 ≤ 6.3
≤ 1.7
1.1
≤ 1.27
2.8
0.7
10
2.6
2.1
ST3.5 ≤ 8.2
≤ 2.35
1.3
≤ 1.4
3.35
0.8
15
3.2
2.5
ST4.2 ≤ 9.4
≤ 2.6
1.4
≤ 1.8
3.95
1
20
3.7
2.8
ST4.8 ≤ 10.4
≤ 2.8
1.6
≤ 2.03
4.5
1.2
25
4.3
3.2
ST5.5 ≤ 11.5
≤ 3
1.8
≤ 2.03
4.5
1.3
25
5
3.6
ST6.3 ≤ 12.6
≤ 3.15
1.8
≤ 2.42
5.6
1.4
30
6
3.6
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.
Size sheet · ISO 14587
ST2.9
dk head diameter ≤ 6.3
k head height ≤ 1.7
a length undercut 1.1
t groove depth ≤ 1.27
A (hexalobular) 2.8
f height of the lens 0.7
recess_no drive size (hexalobular) 10
y length of the point 2.6
y length of the point 2.1 Size sheet · ISO 14587
ST3.5
dk head diameter ≤ 8.2
k head height ≤ 2.35
a length undercut 1.3
t groove depth ≤ 1.4
A (hexalobular) 3.35
f height of the lens 0.8
recess_no drive size (hexalobular) 15
y length of the point 3.2
y length of the point 2.5 Size sheet · ISO 14587
ST4.2
dk head diameter ≤ 9.4
k head height ≤ 2.6
a length undercut 1.4
t groove depth ≤ 1.8
A (hexalobular) 3.95
f height of the lens 1
recess_no drive size (hexalobular) 20
y length of the point 3.7
y length of the point 2.8 Size sheet · ISO 14587
ST4.8
dk head diameter ≤ 10.4
k head height ≤ 2.8
a length undercut 1.6
t groove depth ≤ 2.03
A (hexalobular) 4.5
f height of the lens 1.2
recess_no drive size (hexalobular) 25
y length of the point 4.3
y length of the point 3.2 Size sheet · ISO 14587
ST5.5
dk head diameter ≤ 11.5
k head height ≤ 3
a length undercut 1.8
t groove depth ≤ 2.03
A (hexalobular) 4.5
f height of the lens 1.3
recess_no drive size (hexalobular) 25
y length of the point 5
y length of the point 3.6 Size sheet · ISO 14587
ST6.3
dk head diameter ≤ 12.6
k head height ≤ 3.15
a length undercut 1.8
t groove depth ≤ 2.42
A (hexalobular) 5.6
f height of the lens 1.4
recess_no drive size (hexalobular) 30
y length of the point 6
y length of the point 3.6 Provenance
Reviewed — dimensions cross-checked against the official ISO preview; values match.
Accessed 2026-09-23 · For design and safety-critical use, consult the current edition of the standard.
Data notes (1) Dimensions cross-checked against the official ISO 14587:2011 preview — values match.