Metric coarse bolt chart (ISO 898-1)

15 rows · EngiRef · sample of the first 8 rows

Metric coarse bolt chart (ISO 898-1). Every metric coarse fastener size in the reference on one sheet: pitch, major and external minor diameters, tensile stress area, head height and diameter, and the across-flats wrench size.
Size	Pitch mm	Major dia d mm	Minor dia d₃ mm	Tensile area mm²	Head height mm	Head dia mm	Wrench mm
M3	0.5	3	2.39	5.03	2	5.5	5.5
M4	0.7	4	3.14	8.78	2.8	7	7
M5	0.8	5	4.02	14.2	3.5	8.5	8
M6	1	6	4.77	20.1	4	10	10
M8	1.25	8	6.47	36.6	5.3	13	13
M10	1.5	10	8.16	58	6.4	16	17
M12	1.75	12	9.85	84.3	7.5	18	19
M14	2	14	11.55	115	8.8	21	22

Tensile stress areas follow ISO 898-1, At = (π/4)(d − 0.9382p)². Minor diameter is the EXTERNAL thread minor d₃ = d − 1.2269p. Verify against the current standard and the fastener manufacturer's data before safety-critical design.

Reference values are provided for study and quick reference. Verify against current standards and manufacturer data before safety-critical design.

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