M1.6 is one of the standard coarse-thread sizes for socket head cap screws under ISO 4762 / DIN 912. The sections below reproduce the dimensional row, list the matching tools and hole sizes, and summarize where this size is normally specified.
M1.6 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 |
|---|---|---|---|---|---|---|
| M1.6 | 0.35 | 3.0 | 1.6 | 1.5 | 0.7 | ISO 4762 / DIN 912 |
Spanner & Drive for M1.6 Socket Head Cap Screws
The hex socket for M1.6 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). Ball-end keys are for reaching the screw, not for tightening it — finish on the plain end, and on production work use a torque-controlled driver.
Hole Sizes for M1.6
| Coarse-thread pitch (ISO 724) | 0.35 mm |
|---|---|
| Through-hole / clearance (ISO 273 medium) | 1.8 mm |
| Tapping drill, coarse thread | 1.25 mm |
Tightening Torque for M1.6
| Class 8.8 (dry, ~µ 0.125) | ≈ 0.2 Nm |
|---|---|
| Class 10.9 (dry, ~µ 0.125) | ≈ Nm |
| Class 12.9 (dry, ~µ 0.125) | ≈ 0.3 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 M1.6
| Tensile stress area As (ISO 724) | 1.3 mm² |
|---|---|
| Proof load, class 8.8 | 0.7 kN |
| Proof load, class 12.9 | 1.2 kN |
| Min. ultimate tensile load, class 8.8 | 1 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 M1.6 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 M1.6 the joint is sensitive to over-torque — use a torque-limiting driver and check the head doesn't bury into a softer counterpart.
Mating Parts for M1.6
For M1.6, pair with a M1.6 hex nut (ISO 4032 / DIN 934) and, where used, a M1.6 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 M1.6 socket head cap screws. Lengths and thread lengths outside the standard table are the commonest request, followed by a drive the standard does not offer and a head marked with your own part number. Made by cold heading or warm forging.
Minimum order from 2,000 pieces; samples within 7 days of drawing approval.

