Engineering Tools

Reference data for specifying and sourcing fasteners correctly — the numbers a procurement or design engineer actually needs.

DIN 931 — Hexagon head bolt, partial thread

Also referenced as: ISO 4014 · IS 1364

Sourced dimensions

Same head as DIN 933, but only partially threaded — the shank near the head is left plain/unthreaded, which makes it slightly heavier and often preferred for shear-load joints.

Size	Across flats (S)	Head height (K)	Thread length (b) for L≤125mm
M6	10 mm	4 mm	2d+6 = 18 mm
M8	13 mm	5.5 mm	2d+6 = 22 mm
M10	17 mm	7 mm	2d+6 = 26 mm
M12	19 mm	8 mm	2d+6 = 30 mm
M16	24 mm	10 mm	2d+6 = 38 mm
M20	30 mm	13 mm	2d+6 = 46 mm

Weight reference (kg per 1000 pcs)

Mild steel, computed the same way as the Weight Calculator — for other materials or lengths, use that tool directly.

Size	16mm	20mm	25mm	30mm	35mm	40mm	45mm	50mm	60mm	70mm	80mm	100mm
M6	5.25	6.0	7.11	8.22	9.33	10.44	11.55	12.66	14.88	17.1	19.32	23.76
M8	10.92	12.07	13.83	15.8	17.78	19.75	21.72	23.69	27.64	31.59	35.53	43.42
M10	21.03	22.85	25.13	28.05	31.13	34.21	37.3	40.38	46.54	52.71	58.87	71.2
M12	30.22	32.87	36.18	39.49	43.92	48.36	52.8	57.24	66.12	75.0	83.88	101.63
M16	58.88	63.81	69.98	76.14	82.3	89.16	97.05	104.94	120.72	136.51	152.29	183.86
M20	110.31	118.0	127.61	137.23	146.84	156.45	166.07	177.85	202.52	227.18	251.84	301.16

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