Leading UK Manufacturer of ISO 4014 / DIN 931 Hexagon Bolts.
We specialise in the precision manufacture and supply of high-integrity, partially threaded hexagon bolts in accordance with ISO 4014 and DIN 931 standards.
Designed for demanding construction and engineering applications, our heavy-duty fasteners are engineered for reliability, offering robust clamping performance in critical structural assemblies.
Utilising advanced in-house hot-forging, precision machining, and thread rolling processes, we ensure consistent dimensional accuracy and structural performance across every production run. We offer a versatile range with lengths up to 3000mm and provide full flexibility for non-standard thread lengths to meet your exact project specifications.
| A THREAD DIAMETER |
PITCH OF THREAD | DIA OF SHANK UNTHREADED |
E | F | D | RADIUS UNDER HEAD |
||||
|---|---|---|---|---|---|---|---|---|---|---|
| GRADE B | GRADE B | GRADE B | GRADE B | |||||||
| mm | Coarse Pitch Series | MIN mm |
MAX mm |
MIN mm |
MAX mm |
MIN mm |
MIN mm |
MAX mm |
NOM mm |
MIN mm |
| M12 | 1.75 | 11.57 | 12.00 | 17.57 | 18.00 | 19.85 | 7.21 | 7.79 | 7.50 | 0.60 |
| M16 | 2 | 15.57 | 16.00 | 23.16 | 24.00 | 26.17 | 9.71 | 10.29 | 10.00 | 0.60 |
| M20 | 2.5 | 19.48 | 20.00 | 29.16 | 30.00 | 32.95 | 12.15 | 12.85 | 12.50 | 0.80 |
| (M22) | 2.5 | 21.48 | 22.00 | 33.00 | 34.00 | 37.29 | 13.65 | 14.35 | 14.00 | 0.80 |
| M24 | 3 | 23.48 | 24.00 | 35.00 | 36.00 | 39.55 | 14.65 | 15.35 | 15.00 | 0.80 |
| (M27) | 3 | 26.48 | 27.00 | 40.00 | 41.00 | 45.20 | 13.65 | 17.35 | 17.00 | 1.00 |
| M30 | 3.5 | 29.48 | 30.00 | 45.00 | 46.00 | 50.85 | 18.28 | 19.12 | 18.70 | 1.00 |
| (M33) | 3.5 | 32.38 | 33.00 | 49.00 | 50.00 | 55.37 | 20.58 | 21.42 | 21.00 | 1.00 |
| M36 | 4 | 35.38 | 36.00 | 53.8 | 55.00 | 60.79 | 22.08 | 22.92 | 22.50 | 1.00 |
| (M39) | 4 | 38.38 | 39.00 | 58.80 | 60.00 | 66.44 | 24.58 | 25.42 | 25.00 | 1.00 |
| M42 | 4.5 | 41.38 | 42.00 | 63.10 | 65.00 | 71.30 | 25.58 | 26.42 | 26.00 | 1.20 |
| (M45) | 4.5 | 44.38 | 45.00 | 68.10 | 70.00 | 76.95 | 27.58 | 28.42 | 28.00 | 1.20 |
| M48 | 5 | 47.38 | 48.00 | 73.10 | 75.00 | 82.60 | 29.58 | 30.42 | 30.00 | 1.60 |
| (M52) | 5 | 51.26 | 52.00 | 78.10 | 80.00 | 88.25 | 32.50 | 33.50 | 33.00 | 1.60 |
| M56 | 5.5 | 55.26 | 56.00 | 82.80 | 85.00 | 93.56 | 34.50 | 35.50 | 35.00 | 2.00 |
| (M60) | 5.5 | 59.26 | 60.00 | 87.80 | 90.00 | 99.21 | 37.50 | 38.50 | 38.00 | 2.00 |
| M64 | 6 | 63.26 | 64.00 | 92.80 | 95.00 | 104.86 | 39.50 | 40.50 | 40.00 | 2.00 |
| Normal length of bolt B | Length of thread C |
|---|---|
| Up to and including 125mm | 2A + 6mm |
| Over 125mm up to and including 200mm | 2A + 12mm |
| Over 200mm | 2A + 25mm |
