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Fine Thread Hex Head Bolt Dimensions (ISO 8765 / DIN 960, M8x1 to M30x2)

Guide · Updated October 28, 2026

ISO 8765 covers partially threaded hexagon head bolts with metric fine pitch thread, M8 x 1 to M64 x 4, product grades A and B; it replaced DIN 960. This chart shows the preferred threads M8 x 1 to M30 x 2. Values agree across Fuller Fasteners, fasten.it (DIN EN ISO 8765) and the ISO 8765:2022 published table. b is reference thread length. Full-thread coarse screws: ISO 4017; thin fine nuts: ISO 8675.

Step by step

1. Find the thread: Pick the d x P row, e.g. M12 x 1.5.
2. Pick the b column: Use the column for bolt length l: up to 125, 125 to 200, or over 200 mm.
3. Work out the shank: Plain shank is roughly l minus b; keep the shear plane on the shank.
4. Match the nut: Use a fine-thread nut of the same pitch, e.g. ISO 8673 or ISO 8674.

ISO 8765 fine thread hex head bolt dimensions (mm)

Columns: thread d x P, pitch P, width across flats s, head height k nom., thread length b (ref.) for l ≤ 125, 125 < l ≤ 200 and l > 200 mm.

• Size | P | s | k | b ≤125 | b ≤200 | b >200
• M8 x 1 | 1 | 13 | 5.3 | 22 | 28 | 41
• M10 x 1 | 1 | 16 | 6.4 | 26 | 32 | 45
• M12 x 1.5 | 1.5 | 18 | 7.5 | 30 | 36 | 49
• M16 x 1.5 | 1.5 | 24 | 10 | 38 | 44 | 57
• M20 x 1.5 | 1.5 | 30 | 12.5 | 46 | 52 | 65
• M24 x 2 | 2 | 36 | 15 | 54 | 60 | 73
• M30 x 2 | 2 | 46 | 18.7 | 66 | 72 | 85

Worked example: M16 x 1.5 x 150 bolt

An M16 x 1.5 x 150 ISO 8765 bolt is between 125 and 200 mm long, so b is 44 mm and the plain shank is about 106 mm. It takes a 24 mm spanner and a matching M16 x 1.5 fine nut.

Common problems

• Nut runs out of thread: b too short for the clamp; pick a shorter bolt or ISO 8676 full thread.
• Coarse nut will not start: check the pitch in the designation.
• Wrong b column used: b steps up at 125 and 200 mm length.

FAQ

ISO 8765 vs ISO 8676?

Same head. ISO 8765 bolts are partly threaded with a plain shank; ISO 8676 screws are threaded to the head.

ISO 8765 vs coarse ISO 4014?

Same head and the same b values; only the thread pitch is finer. Coarse ISO 4014 is the first choice for general use.

Is DIN 960 the same?

ISO 8765 replaced DIN 960. DIN 960 used larger flats at M10 and M12 (17 and 19 mm vs ISO 16 and 18).

Why is M30 k 18.7 when one table says 19?

Fuller and the ISO 8676 and ISO 4014 heads give 18.7 mm; 19 appears in one catalog table only.

Related guides and calculators

• Fine thread hex screws (ISO 8676)
• Hex head bolts (ISO 4014)
• Fine thread high hex nuts (ISO 8674)
• All free machinist calculators

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