M2.5 Phillips Countersunk Screws are manufactured to ISO 7046 / DIN 965 with a coarse thread pitch of 0.45 mm. This page lists the controlling dimensions for the M2.5 size — head geometry, width across flats, matching spanner size — together with the clearance hole, tapping drill and tightening torque used at assembly.
M2.5 Dimensional Row (ISO 7046 / DIN 965)
| Size | Pitch (mm) | Head diameter dk (mm) | Head height k (mm) | Cross recess | Countersink angle (deg) | Reference standard |
|---|---|---|---|---|---|---|
| M2.5 | 0.45 | 4.7 | 1.5 | PH1 | 90 | ISO 7046 / DIN 965 |
Spanner & Drive for M2.5 Phillips Countersunk Screws
The hex socket for M2.5 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). For a one-off, a T-handle key and a calibrated arm will do. For a batch, the only way to get the same preload twice is a torque-controlled driver.
Hole Sizes for M2.5
| Coarse-thread pitch (ISO 724) | 0.45 mm |
|---|---|
| Through-hole / clearance (ISO 273 medium) | 2.9 mm |
| Tapping drill, coarse thread | 2.05 mm |
Tightening Torque for M2.5
| Class 8.8 (dry, ~µ 0.125) | ≈ 0.7 Nm |
|---|---|
| Class 10.9 (dry, ~µ 0.125) | ≈ Nm |
| Class 12.9 (dry, ~µ 0.125) | ≈ 1.2 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 M2.5
| Tensile stress area As (ISO 724) | 3.4 mm² |
|---|---|
| Proof load, class 8.8 | 2 kN |
| Proof load, class 12.9 | 3.3 kN |
| Min. ultimate tensile load, class 8.8 | 2.7 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 M2.5 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 M2.5 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 M2.5
For M2.5, pair with a M2.5 hex nut (ISO 4032 / DIN 934) and, where used, a M2.5 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 M2.5 phillips countersunk 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.
