The M27 size of Socket Head Cap Screws is dimensioned by ISO 4762 / DIN 912. The tables below give the dimensional row from the standard, the drill and spanner sizes that go with it, and the assembly torque per property class. The technical drawing on this page redraws to the exact values selected.
M27 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 |
|---|---|---|---|---|---|---|
| M27 | 3.0 | 40.0 | 27.0 | 19.0 | 13.5 | ISO 4762 / DIN 912 |
Spanner & Drive for M27 Socket Head Cap Screws
The hex socket for M27 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 Allen key gives the best feel for setting preload by feel; for production work use a torque-controlled driver.
Common Applications for M27 Socket Head Cap Screws
M27 Socket Head Cap Screws are commonly specified for heavy assembly and large machine mounts.
Installation Tips for M27 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 M27 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 M27
For M27, pair with a M27 hex nut (ISO 4032 / DIN 934) and, where used, a M27 flat washer (ISO 7089 / DIN 125A) under the head and under the nut.
