M22 Socket Head Cap Screws are manufactured to ISO 4762 / DIN 912 with a coarse thread pitch of 2.5 mm. This page lists the controlling dimensions for the M22 size — head geometry, width across flats, matching spanner size — together with the clearance hole, tapping drill and tightening torque used at assembly.
M22 Dimensional Row (ISO 4762 / DIN 912)
| Size | Pitch (mm) | Head diameter dk (mm) | Head height k (mm) | Hex key s (mm) | Socket depth t min (mm) | Reference standard |
|---|---|---|---|---|---|---|
| M22 | 2.5 | 33.0 | 22.0 | 17.0 | 11.0 | ISO 4762 / DIN 912 |
Spanner & Drive for M22 Socket Head Cap Screws
The hex socket for M22 Socket Head Cap 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 key gives the most feel when you are judging preload by hand; anything repeated across a batch wants a torque-controlled driver instead.
Hole Sizes for M22
| Coarse-thread pitch (ISO 724) | 2.5 mm |
|---|---|
| Through-hole / clearance (ISO 273 medium) | 24 mm |
| Tapping drill, coarse thread | 19.5 mm |
Tightening Torque for M22
| Class 8.8 (dry, ~µ 0.125) | ≈ 573 Nm |
|---|---|
| Class 10.9 (dry, ~µ 0.125) | ≈ 816 Nm |
| Class 12.9 (dry, ~µ 0.125) | ≈ 954 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 M22
| Tensile stress area As (ISO 724) | 303 mm² |
|---|---|
| Proof load, class 8.8 | 182 kN |
| Proof load, class 10.9 | 252 kN |
| Proof load, class 12.9 | 294 kN |
| Min. ultimate tensile load, class 8.8 | 252 kN |
Proof load = tensile stress area × the proof stress Sp of the class, per ISO 898-1 — Sp is a lower figure than the yield stress Rp0.2 and the two are not interchangeable. The stress area is computed from this size's own diameter and pitch, so a fine-pitch designation gives the fine-pitch figure. Design the joint so the working preload stays below the proof load of the class selected.
Installation Tips for M22 Socket Head Cap 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 M22 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 M22
For M22, pair with a M22 hex nut (ISO 4032 / DIN 934) and, where used, a M22 flat washer (ISO 7089 / DIN 125A) under the head and under the nut.
Custom manufacturing · Made to drawing
Need socket head cap screws in a size this table does not list?
This page covers M22 socket head cap screws. Where the standard stops, the drawing takes over: fine pitches, left-hand threads, partial threading, and property classes above the catalogued grade where material and heat treatment allow. Made by cold heading or warm forging.
Minimum order from 2,000 pieces; samples within 7 days of drawing approval.
