ISO 14579 dimensions — Hexalobular socket head cap screws
2011 edition, current · 13 sizes, M2 – M20 see the cross-reference →
✓We supply to ISO 14579. Name it on your order.
ISO 14579 dimensions
| Thread size | PThread Pitch (mm) | dkHead Diameter (mm) | dkHead Diameter (min) (mm) | kNominal Head Height (mm) | kHead Height (min) (mm) | rRadius (min) (mm) | Recess Number | mType H Recess Width (ref.) (mm) | tSocket Depth (max) (mm) | tSocket Depth (min) (mm) | bThread Length (mm) | Clearance holefine / medium / coarse (mm) | Tap drillcoarse pitch (mm) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| M2 | 0.4 | 3.8 | 3.62 | 2 | 1.86 | 0.1 | 6 | 1.75 | 0.84 | 0.71 | 16 | 2.2 / 2.4 / 2.6 | 1.6 |
| M2.5 | 0.45 | 4.5 | 4.32 | 2.5 | 2.36 | 0.1 | 8 | 2.4 | 1.04 | 0.91 | 17 | 2.7 / 2.9 / 3.1 | 2.05 |
| M3 | 0.5 | 5.5 | 5.32 | 3 | 2.86 | 0.1 | 10 | 2.8 | 1.27 | 1.01 | 18 | 3.2 / 3.4 / 3.6 | 2.5 |
| M4 | 0.7 | 7 | 6.78 | 4 | 3.82 | 0.2 | 20 | 3.95 | 1.8 | 1.42 | 20 | 4.3 / 4.5 / 4.8 | 3.3 |
| M5 | 0.8 | 8.5 | 8.28 | 5 | 4.82 | 0.2 | 25 | 4.5 | 2.03 | 1.65 | 22 | 5.3 / 5.5 / 5.8 | 4.2 |
| M6 | 1 | 10 | 9.78 | 6 | 5.7 | 0.25 | 30 | 5.6 | 2.42 | 2.02 | 24 | 6.4 / 6.6 / 7 | 5 |
| M8 | 1.25 | 13 | 12.73 | 8 | 7.64 | 0.4 | 45 | 7.95 | 3.31 | 2.92 | 28 | 8.4 / 9 / 10 | 6.8 |
| M10 | 1.5 | 16 | 15.73 | 10 | 9.64 | 0.4 | 50 | 8.95 | 4.02 | 3.62 | 32 | 10.5 / 11 / 12 | 8.5 |
| M12 | 1.75 | 18 | 17.73 | 12 | 11.57 | 0.6 | 55 | 11.35 | 5.21 | 4.82 | 36 | 13 / 13.5 / 14.5 | 10.2 |
| M14 | 2 | 21 | 20.67 | 14 | 13.57 | 0.6 | 60 | 13.45 | 5.99 | 5.62 | 40 | 15 / 15.5 / 16.5 | 12 |
| M16 | 2 | 24 | 23.67 | 16 | 15.57 | 0.6 | 70 | 15.7 | 7.01 | 6.62 | 44 | 17 / 17.5 / 18.5 | 14 |
| M18 | 2.5 | 27 | 26.67 | 18 | 17.57 | 0.6 | 80 | 17.75 | 8 | 7.5 | 48 | 19 / 20 / 21 | 15.5 |
| M20 | 2.5 | 30 | 29.67 | 20 | 19.48 | 0.8 | 90 | 20.2 | 9.2 | 8.69 | 52 | 21 / 22 / 24 | 17.5 |
13 of 13 sizes shown. Clearance holes are fine / medium / coarse to ISO 273; tap drill is for the coarse pitch.
What we supply to ISO 14579
3 materials| Material | Property class | Finish |
|---|---|---|
| Carbon Steel | 8.8 | Blackened · Zinc Plated · Plain |
| Alloy Steel | 10.9 | Blackened · Zinc Plated · Plain |
| Stainless Steel | A2-70 · A4-80 | Plain · Passivated |
Property classes
ISO 898-1 · ISO 3506-1| Class | Rm min. | Yield requirement | Elongation requirement | Hardness | Typical use |
|---|---|---|---|---|---|
| 8.8 (d <= M16) | 800 MPa | Rp0.2 min. 640 MPa | A min. 12 % | 250 - 320 HV | The general-purpose structural class — steel-to-steel joints, machinery, vehicle assembly. Assume this if no class is stated. |
| 8.8 (d > M16) | 830 MPa | Rp0.2 min. 660 MPa | A min. 12 % | 255 - 335 HV | |
| A2-70 | 700 MPa | Rp0.2 min. 450 MPa | 0,4d mm | - | Cold-worked austenitic stainless, typically 304 — outdoor, wet and food service away from chlorides. |
| A4-80 | 800 MPa | Rp0.2 min. 600 MPa | 0,3d mm | - | The strongest 316-type class; marine and chemical service where 70 does not carry the load. |
| 10.9 | 1040 MPa | Rp0.2 min. 940 MPa | A min. 9 % | 320 - 380 HV | Preloaded high-tension joints — engine, gearbox and structural connections that grip by friction. Needs controlled tightening. |
These values meet the requirements of ISO 898-1 / ISO 3506-1. We supply to these classes and issue the matching mill certificate and third-party test report with your order.
