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Light-Duty Slotted Spring Pin Dimensions (ISO 13337 / DIN 7346, 2 to 50 mm)

Guide · Updated October 28, 2026

ISO 13337 covers light-duty slotted spring pins (it replaced DIN 7346), 2 to 50 mm. Diameters, wall and chamfer come from the ISO 13337:2009 preview (iTeh). Engineering Hardware ISO 13337 agrees on d2 and s and on the midpoints of d1 and a. Boltport agrees on d1 min, d2 and shear for the sizes it lists. Check your supplier for critical work.

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Step by step

Pick the nominal size: d1 nom equals the hole size, 2 to 50 mm.
Check the free diameter: A new pin measures between d1 max and d1 min before fitting.
Check the wall: s is the wall thickness; light duty is thinner than ISO 8752.
Nest if needed: A light-duty pin fits inside the heavy-duty ISO 8752 pin of the matching size; turn the slots 180° apart.
Order it: Designate as Spring pin ISO 13337 - 6 x 30 - St.

ISO 13337 light-duty spring pin dimensions (mm)

Columns: nominal size, d1 max and min before fitting, inside diameter d2 (reference), chamfer a max and min, wall s, minimum double shear (kN, steel).

nom | d1 max | d1 min | d2 | a max | a min | s | shear kN
2 | 2.4 | 2.3 | 1.9 | 0.4 | 0.2 | 0.2 | 1.5
2.5 | 2.9 | 2.8 | 2.3 | 0.45 | 0.25 | 0.25 | 2.4
3 | 3.5 | 3.3 | 2.7 | 0.45 | 0.25 | 0.3 | 3.5
3.5 | 4.0 | 3.8 | 3.1 | 0.5 | 0.3 | 0.35 | —
4 | 4.6 | 4.4 | 3.4 | 0.7 | 0.5 | 0.5 | 8
4.5 | 5.1 | 4.9 | 3.9 | 0.7 | 0.5 | 0.5 | —
5 | 5.6 | 5.4 | 4.4 | 0.7 | 0.5 | 0.5 | 10.4
6 | 6.7 | 6.4 | 4.9 | 0.9 | 0.7 | 0.75 | 18
8 | 8.8 | 8.5 | 7.0 | 1.8 | 1.5 | 0.75 | 24
10 | 10.8 | 10.5 | 8.5 | 2.4 | 2.0 | 1.0 | 40
12 | 12.8 | 12.5 | 10.5 | 2.4 | 2.0 | 1.0 | 48
13 | 13.8 | 13.5 | 11 | 2.4 | 2.0 | 1.2 | 66
14 | 14.8 | 14.5 | 11.5 | 2.4 | 2.0 | 1.5 | —
16 | 16.8 | 16.5 | 13.5 | 2.4 | 2.0 | 1.5 | 98
18 | 18.9 | 18.5 | 15.0 | 2.4 | 2.0 | 1.7 | —
20 | 20.9 | 20.5 | 16.5 | 2.4 | 2.0 | 2.0 | —
21 | 21.9 | 21.5 | 17.5 | 2.4 | 2.0 | 2.0 | 168
25 | 25.9 | 25.5 | 21.5 | 3.4 | 3.0 | 2.0 | —
28 | 28.9 | 28.5 | 23.5 | 3.4 | 3.0 | 2.5 | —
30 | 30.9 | 30.5 | 25.5 | 3.4 | 3.0 | 2.5 | —
35 | 35.9 | 35.5 | 28.5 | 3.6 | 3.0 | 3.5 | —
40 | 40.9 | 40.5 | 32.5 | 4.6 | 4.0 | 4.0 | —
45 | 45.9 | 45.5 | 37.5 | 4.6 | 4.0 | 4.0 | —
50 | 50.9 | 50.5 | 40.5 | 4.6 | 4.0 | 5.0 | —

Worked example: 6 mm light-duty pin

A 6 mm ISO 13337 pin measures 6.4 to 6.7 mm before fitting, has a 0.75 mm wall and goes in a 6 mm hole. Nested inside a 6 mm ISO 8752 pin, it adds shear strength in the same hole.

Common problems

Pin loose: check the free diameter; a used pin may have lost its spring.
Pin sheared: switch to heavy-duty ISO 8752 or nest two pins.
Nested pins interlock: turn the slots 180° apart.

FAQ

What is ISO 13337?

Light-duty slotted spring pins, 2 to 50 mm, steel or stainless. It replaced DIN 7346.

How is it different from ISO 8752?

Same hole sizes but a thinner wall (e.g. 0.75 mm vs 1.2 mm at 6 mm) and lower shear strength. The thinner pin suits softer parts and nests inside a heavy-duty pin.

How is it different from ISO 8748 coiled pins?

Coiled pins are rolled spirals; ISO 13337 pins are a single slotted tube.

Why are some shear values dashed?

Shear strength agrees between the ISO 13337:2009 preview and Boltport for the sizes Boltport lists. The other sizes had only one source, so they are dashed.

What was skipped?

Per-size length ranges (graphic in the preview) and the shear values with only one source.

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