DIN 3015 Clamp Bolt Torque Quick Reference
Select your clamp series and size group to get the recommended tightening torque. Clamp torque is NOT generic bolt-yield torque — plastic-insert clamps need far lower values.
Bolt: M6×20
Recommended torque: 4 Nm
Do not exceed: 6 Nm
Full torque tables
WQL — DIN 3015-1 — PP / PA insert
| Group | Tube OD (mm) | Bolt | Recommended (Nm) | Maximum (Nm) |
|---|---|---|---|---|
| L0 / L1 | 6 – 12 | M6×20 | 4 | 6 |
| L2 | 12.7 – 18 | M6×25 | 4 | 6 |
| L3 | 19 – 25 | M6×30 | 5 | 6 |
| L4 | 26.9 – 30 | M6×35 | 5 | 6 |
| L5 | 32 – 42 | M6×50 | 5 | 7 |
| L6 | 44.5 – 50.8 | M6×60 | 6 | 8 |
| L7 | 57.2 – 73 | M6×90 | 6 | 8 |
| L8 | 76.1 – 102 | M6×110 | 6 | 8 |
WQT — DIN 3015-3 — PP / PA insert
| Group | Tube OD (mm) | Bolt | Recommended (Nm) | Maximum (Nm) |
|---|---|---|---|---|
| T1 | 6 – 12 | M6 | 4 | 6 |
| T2 – T5 | 12.7 – 42 | M8 | 10 | 14 |
WQH — DIN 3015-2 — Metal body · class 8.8 bolts
| Group | Tube OD (mm) | Bolt | Recommended (Nm) |
|---|---|---|---|
| H1 | 6 – 18 | M10×45 | 35 |
| H2 | 18 – 30 | M10×60 | 35 |
| H3 | 30 – 42 | M10×70 | 35 |
| H4 | 42 – 75 | M12×100 | 65 |
| H5 | 75 – 88.9 | M16×130 | 155 |
| H6 | 88.9 – 114 | M20×190 | 310 |
| H7 | 140 – 177.8 | M24×220 | 535 |
| H8 | 193.7 – 219 | M30×300 | 1050 |
| H9 | 219 – 273 | M30×450 | 1050 |
| H10 | 356 – 406 | M30×560 | 1050 |
| H11 | 419 – 508 | M36×710 | 1850 |
Before you tighten
- Plastic-insert values seat the clamp body — generic 8.8 bolt charts would crack the PP/PA insert.
- Stainless bolts: apply ~0.85× with anti-seize to prevent galling.
- Tighten body bolts evenly in steps so both halves close parallel to the tube.
Frequently asked questions
Why is the clamp torque so much lower than standard bolt torque charts?
Standard charts target ~70% of bolt yield for structural joints. A pipe clamp only needs to seat the body halves and grip the tube; on PP/PA inserts the plastic cracks long before the bolt yields, so the working torque is set by the insert, not the bolt.
Can I use these values for stainless steel bolts?
Apply roughly a 0.85× factor and use anti-seize: stainless has lower yield than class 8.8 and a higher, more variable friction coefficient that promotes galling. See the stainless torque guide for full tables.
Do I need a torque wrench for small M6 clamp bolts?
For critical lines, yes — 4-6 Nm is easy to exceed by feel. For general service, tighten until the body halves seat evenly and stop; never keep pulling after contact.
Found your size group? Get a quote in 24 hours
Send us the OD, size group, quantity and mounting type — our engineers confirm the exact part number and quote within one working day.