DINboltsHexagon head

DIN 931 Hexagon Head Bolt — Partial Thread

Same head as DIN 933 but with an unthreaded shank under the head. The plain shank carries shear load, which is why these are preferred for structural steelwork and machinery frames.

DIN 931 M12 × 140 — Hexagon headNominal dimensions in mm · Not to scale

Dimensions12 sizes · millimetres

Thread d	Pitch P (mm)	Width across flats s (mm)	Width across corners e (mm)	Head height k (mm)	Thread length b (L ≤ 125 mm) (mm)
M4	0.7	7	7.66	2.8	14
M5	0.8	8	8.79	3.5	16
M6	1	10	11.05	4	18
M8	1.25	13	14.38	5.3	22
M10	1.5	16	17.77	6.4	26
M12	1.75	18	20.03	7.5	30
M14	2	21	23.35	8.8	34
M16	2	24	26.75	10	38
M18	2.5	27	30.14	11.5	42
M20	2.5	30	33.53	12.5	46
M22	2.5	34	37.72	14	50
M24	3	36	39.98	15	54

Nominal dimensions in millimetres as published in DIN 931. Tolerances, material requirements and marking are defined separately by the issuing body.

Available sizeslinked to individual specification pages

M40.7 mm pitch

M4 × 20 M4 × 25 M4 × 30 M4 × 35 M4 × 40 M4 × 50 M4 × 60 M4 × 70 M4 × 80

M50.8 mm pitch

M5 × 20 M5 × 25 M5 × 30 M5 × 35 M5 × 40 M5 × 50 M5 × 60 M5 × 70 M5 × 80

M6 × 20 M6 × 25 M6 × 30 M6 × 35 M6 × 40 M6 × 50 M6 × 60 M6 × 70 M6 × 80 M6 × 100

M81.25 mm pitch

M8 × 25 M8 × 30 M8 × 35 M8 × 40 M8 × 50 M8 × 60 M8 × 70 M8 × 80 M8 × 100 M8 × 120

M101.5 mm pitch

M10 × 25 M10 × 30 M10 × 35 M10 × 40 M10 × 50 M10 × 60 M10 × 70 M10 × 80 M10 × 100 M10 × 120

M121.75 mm pitch

M12 × 30 M12 × 35 M12 × 40 M12 × 50 M12 × 60 M12 × 70 M12 × 80 M12 × 100 M12 × 120 M12 × 140

M14

M14 × 35 M14 × 40 M14 × 50 M14 × 60 M14 × 70 M14 × 80 M14 × 100 M14 × 120 M14 × 140

M16

M16 × 35 M16 × 40 M16 × 50 M16 × 60 M16 × 70 M16 × 80 M16 × 100 M16 × 120 M16 × 140 M16 × 160

M182.5 mm pitch

M18 × 40 M18 × 50 M18 × 60 M18 × 70 M18 × 80 M18 × 100 M18 × 120 M18 × 140 M18 × 160

M202.5 mm pitch

M20 × 40 M20 × 50 M20 × 60 M20 × 70 M20 × 80 M20 × 100 M20 × 120 M20 × 140 M20 × 160 M20 × 180

M222.5 mm pitch

M22 × 50 M22 × 60 M22 × 70 M22 × 80 M22 × 100 M22 × 120 M22 × 140 M22 × 160 M22 × 180

M24

M24 × 50 M24 × 60 M24 × 70 M24 × 80 M24 × 100 M24 × 120 M24 × 140 M24 × 160 M24 × 180 M24 × 200

Thread referencesused by the sizes above

M4 × 0.7 M5 × 0.8 M8 × 1.25 M10 × 1.5 M12 × 1.75 M18 × 2.5 M20 × 2.5 M22 × 2.5