M36 Hex Nuts, Grade C are manufactured to ISO 4034. This page lists the controlling dimensions for the M36 size together with the drive and the installation notes for this type.
M36 Dimensional Row (ISO 4034)
| Size | Pitch (mm) | Width across flats s (mm) | Width across corners e min (mm) | Nut height m (mm) | Product grade | Reference standard |
|---|---|---|---|---|---|---|
| M36 | 4.0 | 55.0 | 60.79 | 31.0 | Grade C | ISO 4034 / DIN 555 |
Spanner & Drive for M36 Hex Nuts, Grade C
M36 Hex Nuts, Grade C have a width across flats of 55.0 mm — fit a 55.0 mm open-ended spanner or socket. Use a 6-point socket for tight clearances and to reduce rounding; for repeated assembly choose a torque wrench so the joint preload is repeatable.
Tightening Torque for M36
| Class 8.8 (dry, ~µ 0.125) | ≈ 2450 Nm |
|---|---|
| Class 10.9 (dry, ~µ 0.125) | ≈ 3450 Nm |
| Class 12.9 (dry, ~µ 0.125) | ≈ 4150 Nm |
Indicative dry-joint values. Lubrication can lower the required torque by 15–25%. Always confirm against the joint design, especially when going up a strength class.
Proof Load & Strength for M36
| Tensile stress area As (ISO 898-1) | 817 mm² |
|---|---|
| Proof load, class 8.8 | 490 kN |
| Proof load, class 10.9 | 678 kN |
| Proof load, class 12.9 | 792 kN |
| Min. ultimate tensile, class 8.8 | 654 kN |
Proof load = stress area × proof stress per ISO 898-1. Design joints so the working preload stays below the proof load of the selected class.
Common Applications for M36 Hex Nuts, Grade C
M36 Hex Nuts, Grade C are commonly specified for structural joints, flange connections and heavy equipment foundations.
Installation Tips for M36 Hex Nuts, Grade C
- Use a 6-point socket where access allows — 12-point sockets are more prone to rounding the corners on smaller sizes.
- On flanged or serrated variants, do NOT add a separate flat washer — the flange already spreads the load and the washer can defeat the locking serrations.
- At M36 the stretch in the bolt becomes the controlling factor — for critical joints, use angle-controlled or stretch-controlled tightening instead of pure torque.
Mating Parts for M36
Pair M36 with the matching M36 bolt or screw, plus a M36 flat washer where required to distribute load on softer materials.
