M36 Socket Set Screws are manufactured to ISO 4026 / ISO 4029 / DIN 913-916 with a coarse thread pitch of 4 mm. This page lists the controlling dimensions for the M36 size — head geometry, width across flats, matching spanner size — together with the clearance hole, tapping drill and tightening torque used at assembly.
M36 Dimensional Row (ISO 4026 / ISO 4029 / DIN 913-916)
| Size | Pitch (mm) | Hex socket s (mm) | Engagement depth t min (mm) | Point diameter dp (mm) | End type | Reference standard |
|---|---|---|---|---|---|---|
| M36 | 4.0 | 17.0 | 19.0 | 27.0 | Flat point | ISO 4026 / DIN 913-916 |
Spanner & Drive for M36 Socket Set Screws
The hex socket for M36 Socket Set Screws is shown in the spec table — use the matching Allen / hex key (an ISO 2936 hex key set covers the full range). A T-handle Allen key gives the best feel for setting preload by feel; for production work use a torque-controlled driver.
Hole Sizes for M36
| Coarse-thread pitch (ISO 724) | 4 mm |
|---|---|
| Through-hole / clearance (ISO 273 medium) | 39 mm |
| Tapping drill, coarse thread | 32 mm |
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 Socket Set Screws
M36 Socket Set Screws are commonly specified for heavy assembly and large machine mounts.
Installation Tips for M36 Socket Set Screws
- Use a quality Allen key fully seated in the socket — partial engagement is the most common cause of stripped sockets at this size.
- For countersunk and button-head variants, chamfer the through-hole to seat the head flush without preloading the head/shank fillet.
- 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
For M36, pair with a M36 hex nut (ISO 4032 / DIN 934) and, where used, a M36 flat washer (ISO 7089 / DIN 125A) under the head and under the nut.