DIN 6921 dimensions — Hexagon Flange Bolt
Withdrawn as a document · 8 sizes, M5 – M20 · the part is still made and ordered to it see the cross-reference →
✓We supply to DIN 6921. Name it on your order — your drawing does not need changing.
DIN 6921 dimensions
| Thread size | PThread Pitch (mm) | sWidth Across Flats (max) (mm) | eWidth Across Corners (min) (mm) | dcFlange Diameter (mm) | kNominal Head Height (mm) | bThread Length (L <= 125) (mm) | bThread Length (125 < L <= 200) (mm) | bThread Length (L > 200) (mm) | Clearance holefine / medium / coarse (mm) | Tap drillcoarse pitch (mm) |
|---|---|---|---|---|---|---|---|---|---|---|
| M5 | 0.8 | 8 | 8.79 | 11.8 | 6.2 | 16 | - | - | 5.3 / 5.5 / 5.8 | 4.2 |
| M6 | 1 | 10 | 11.05 | 14.2 | 7.3 | 18 | - | - | 6.4 / 6.6 / 7 | 5 |
| M8 | 1.25 | 13 | 14.38 | 17.9 | 9.4 | 22 | 28 | - | 8.4 / 9 / 10 | 6.8 |
| M10 | 1.5 | 15 | 16.64 | 21.8 | 11.4 | 26 | 32 | - | 10.5 / 11 / 12 | 8.5 |
| M12 | 1.75 | 18 | 20.03 | 26 | 13.8 | 30 | 36 | - | 13 / 13.5 / 14.5 | 10.2 |
| M14 | 2 | 21 | 23.36 | 29.9 | 15.9 | 34 | 40 | - | 15 / 15.5 / 16.5 | 12 |
| M16 | 2 | 24 | 26.75 | 34.5 | 18.3 | 38 | 44 | 57 | 17 / 17.5 / 18.5 | 14 |
| M20 | 2.5 | 30 | 32.95 | 42.8 | 22.4 | 46 | 52 | 65 | 21 / 22 / 24 | 17.5 |
8 of 8 sizes shown. Clearance holes are fine / medium / coarse to ISO 273; tap drill is for the coarse pitch.
What we supply to DIN 6921
3 materials| Material | Property class | Finish |
|---|---|---|
| Carbon Steel | 4.8 · 8.8 | Plain · Zinc Plated · Dacromet · Blackened · Phosphate · Hot Dip Galvanized |
| Alloy Steel | 10.9 | Plain · Zinc Plated · Dacromet · Blackened · Phosphate |
| Stainless Steel | A2-70 · A4-80 | Passivated · Plain |
Property classes
ISO 898-1 · ISO 3506-1| Class | Rm min. | Yield requirement | Elongation requirement | Hardness | Typical use |
|---|---|---|---|---|---|
| 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. |
| 4.8 | 420 MPa | Rpf min. 340 MPa (not a test value) | Af min. 0.24 | 130 - 220 HV | Light-duty non-structural work; the low-cost class for large sizes carrying little load. |
| 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 |
These values meet the requirements of ISO 3506-1 / ISO 898-1. We supply to these classes and issue the matching mill certificate and third-party test report with your order.
