M1.6 is one of the standard coarse-thread sizes for phillips countersunk screws under ISO 7046 / DIN 965. 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 7046 / DIN 965)
| Size | Pitch (mm) | Head diameter dk (mm) | Head height k (mm) | Cross recess | Countersink angle (deg) | Reference standard |
|---|---|---|---|---|---|---|
| M1.6 | 0.35 | 3.0 | 0.96 | PH0 | 90 | ISO 7046 / DIN 965 |
Spanner & Drive for M1.6 Phillips Countersunk Screws
The hex socket for M1.6 Phillips Countersunk 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 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 Phillips Countersunk 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 phillips countersunk screws in a size this table does not list?
This page covers M1.6 phillips countersunk screws. Material and finish are usually what drives a special — a grade the standard part is not stocked in, or a coating chosen against a salt-spray figure instead of a default. Made by cold heading or warm forging.
Minimum order from 2,000 pieces; samples within 7 days of drawing approval.

