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Spring Cotter Pin (R-Clip) Dimensions (DIN 11024, 2.5 to 8 mm)

Guide · Updated October 28, 2026

DIN 11024 covers spring cotter pins (R-clips), form D double coil, from 2.5 to 8 mm. Values agree across fasten.it, fasteners.eu, Fixawell and the Seimatec datasheet. Check your supplier for critical work.

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Step by step

Measure the shaft: Find the row whose shaft range d2 covers your pin or shaft diameter.
Drill the hole: Drill the cross hole to d1 (H13). The clip wire d3 is slightly smaller.
Check the length: l1 is the overall length. l2 runs from the leg to the loop centre.
Fit it: Push the straight leg through the hole. The curved leg springs over the shaft.
Inspect: Replace clips that have taken a set or lost their spring.

DIN 11024 spring cotter pin dimensions (mm)

Columns: hole d1 (H13), shaft range d2, wire d3, loop d4, length l1, leg to loop l2, end height l3, height h, radii r1 and r2.

d1 | d2 shaft | d3 | d4 | l1 | l2 | l3 | h | r1 | r2
2.5 | 9–11.2 | 2.25 | 20 | 42 | 24 | 5.5 | 2.5 | 5.6 | 4
3.2 | 11.2–14 | 2.8 | 20 | 48 | 26 | 7 | 3 | 7 | 5
4 | 14–20 | 3.6 | 20 | 64 | 32 | 10 | 4.5 | 10 | 6.5
5 | 20–26 | 4.5 | 25 | 80 | 39 | 12.5 | 7 | 13 | 8
6.3 | 26–34 | 5.6 | 25 | 97 | 45 | 16 | 9 | 17 | 10
7 | 34–45 | 6.3 | 30 | 125 | 56 | 21 | 12.5 | 22.5 | 11.5
8 | 45–56 | 7 | 30 | 150 | 63 | 25.5 | 17.5 | 28 | 12.5

Worked example: 22 mm hitch pin

A 22 mm pin falls in the 20–26 mm range. Use the 5 mm clip (4.5 mm wire, 80 mm long) and drill a 5 mm cross hole.

Common problems

Clip falls off: the shaft is below the d2 range, so use the next size down.
Will not go over the shaft: the shaft is above the range.
Clip has rusted or taken a set: replace it, they are cheap.

FAQ

What is DIN 11024?

The spring cotter pin, also called an R-clip, hairpin or Federstecker. It retains clevis and hitch pins and can be removed by hand.

How do I size one?

Use the shaft diameter: pick the row whose d2 range covers it, then drill the cross hole to d1.

Single or double coil?

The DIN table is form D with a double coil. Single-coil market sizes vary by supplier, so they are not charted.

R-clip or cotter pin?

R-clips are reusable and quick to fit. Split cotter pins are cheaper and more secure, but single-use.

What was skipped?

Weight and single-coil sizes. All shown columns agree across the sources.

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General shop information only — follow your drawing, tool maker's data and your quality system.