Standards and grades
ISO 4014 bolt: dimensions and reference thread length
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ISO 4014 is the hex head bolt with a partial thread and replaces DIN 931. Across flats and head height are the same as on ISO 4017, with the same change in across flats at M10, M12, M14 and M22 compared with the DIN standard.
What defines this bolt is the thread length b. The standard sets it at 2d + 6 mm up to 125 mm in length, 2d + 12 mm between 125 and 200 mm and 2d + 25 mm above 200 mm. The rest of the shank is plain.
| Thread size | DIN 931 across flats | ISO 4014 across flats |
|---|---|---|
| M10 | 17 mm | 16 mm |
| M12 | 19 mm | 18 mm |
| M14 | 22 mm | 21 mm |
| M22 | 32 mm | 34 mm |
| All other sizes | Same | Same |
Thread length b in ISO 4014
| Thread size | b if l ≤ 125 | b if 125 < l ≤ 200 | b if l > 200 |
|---|---|---|---|
| M6 | 18 | 24 | 37 |
| M8 | 22 | 28 | 41 |
| M10 | 26 | 32 | 45 |
| M12 | 30 | 36 | 49 |
| M16 | 38 | 44 | 57 |
| M20 | 46 | 52 | 65 |
| M24 | 54 | 60 | 73 |
| M30 | 66 | 72 | 85 |
Reference values in millimetres; l is the nominal length of the bolt. For larger sizes, contact us.