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Standard-Duty Coiled Spring Pin Dimensions (ISO 8750, 0.8 to 20 mm)

Guide · Updated October 28, 2026

ISO 8750 covers standard-duty coiled spring pins, 0.8 to 20 mm. Values agree between the ISO 8750:2007 preview (iTeh) and the Westfield ISO 8750 table. fasten.it DIN EN ISO 8750 also agrees on d2, a, s and shear. Check your supplier for critical work.

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Step by step

Pick the pin size: Nominal d1, 0.8 to 20 mm, equals the hole size. Drill to H12 (H10 up to 1.2 mm).
Check the strip: s is the coiled strip thickness. Standard duty sits between light ISO 8751 and heavy ISO 8748.
Check the load: Use the steel or martensitic column, or the austenitic column for A pins.
Order it: Designate as Spring pin ISO 8750 - 6 x 30 - St.

ISO 8750 standard-duty coiled spring pin dimensions (mm)

Columns: nominal d1, d1 before fitting (min–max), d2 max, chamfer a ≈, strip s, minimum double shear kN (steel and martensitic), same (austenitic).

Nominal | d1 before fitting | d2 max | a | s | shear kN steel | shear kN austenitic
0.8 | 0.85–0.91 | 0.75 | 0.3 | 0.07 | 0.4 | 0.3
1 | 1.05–1.15 | 0.95 | 0.3 | 0.08 | 0.6 | 0.45
1.2 | 1.25–1.35 | 1.15 | 0.4 | 0.1 | 0.9 | 0.65
1.5 | 1.62–— | 1.4 | 0.5 | 0.13 | 1.45 | 1.05
2 | 2.13–2.25 | 1.9 | 0.7 | 0.17 | 2.5 | 1.9
2.5 | 2.65–2.78 | 2.4 | 0.7 | 0.21 | 3.9 | 2.9
3 | 3.15–3.30 | 2.9 | 0.9 | 0.25 | 5.5 | 4.2
3.5 | 3.67–3.84 | 3.4 | 1 | 0.29 | 7.5 | 5.7
4 | 4.2–4.4 | 3.9 | 1.1 | 0.33 | 9.6 | 7.6
5 | 5.25–5.50 | 4.85 | 1.3 | 0.42 | 15 | 11.5
6 | 6.25–6.50 | 5.85 | 1.5 | 0.5 | 22 | 16.8
8 | 8.30–8.63 | 7.8 | 2 | 0.67 | 39 | 30
10 | 10.35–10.80 | 9.75 | 2.5 | 0.84 | 62 | 48
12 | 12.40–12.85 | 11.7 | 3 | 1 | 89 | 67
14 | 14.45–14.95 | 13.6 | 3.5 | 1.2 | 120 | n/a
16 | 16.45–17.00 | 15.6 | 4 | 1.3 | 155 | n/a
20 | 20.4–21.1 | 19.6 | 4.5 | 1.7 | 250 | n/a

Worked example: 6 mm standard-duty coiled pin

A 6 x 30 ISO 8750 pin goes into a 6 mm H12 hole. Before fitting it measures 6.25 to 6.50 mm, and the 0.5 mm strip coils down to fit. In steel it holds at least 22 kN in double shear.

Common problems

Pin loose: hole oversize; do not ream larger.
Pin shears: move to ISO 8748 heavy duty.
Host cracks: drop to ISO 8751 light duty.

FAQ

What is ISO 8750?

The standard-duty coiled (spiral) spring pin, 0.8 to 20 mm. It is the general-purpose coiled pin. ISO 8748 is heavy duty and ISO 8751 light duty.

How does it compare?

At 6 mm the strip is 0.5 mm here against 0.33 mm on ISO 8751 light duty, and steel shear is 22 kN against 13 kN.

Why is 1.5 mm d1 max blank?

The ISO 8750 PDF gives 1.73 mm and the Westfield ISO 8750 table 1.75 mm, so we dashed it. d1 min is 1.62 in both.

Why n/a austenitic shear above 12 mm?

ISO 8750 gives no austenitic value for 14, 16 and 20 mm.

What was skipped?

Length ranges per size.

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