Dimensional and assembly data for M8 Phillips Oval Countersunk Head Machine Screws, Metric to ISO 7047. Includes head size and width across flats, clearance-hole and tapping-drill diameters, tightening torque per property class, and the sizes to step up or down to when the joint requires it.
M8 Dimensional Row (ISO 7047)
| Size | Pitch P (mm) | a (mm) | b (mm) | Head diameter dk (mm) | csh_diam (mm) | csh_height (mm) | n_min (mm) | r (mm) | t_mean (mm) | x (mm) | Length range l (mm) | Reference standard |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| M8 | 1.25 | 2.5 | 38 | 17.3 | 15.6 | 4.65 | 2.06 | 1.0 | 2.0 | 3.2 | 10~60 | ISO 7047 |
Spanner & Drive for M8 Phillips Oval Countersunk Head Machine Screws, Metric
Drive geometry for M8 Phillips Oval Countersunk Head Machine Screws, Metric is given by the row above; match the tool to the listed values.
Hole Sizes for M8
| Coarse-thread pitch (ISO 724) | 1.25 mm |
|---|---|
| Through-hole / clearance (ISO 273 medium) | 9 mm |
| Tapping drill, coarse thread | 6.75 mm |
Tightening Torque for M8
| Class 8.8 (dry, ~µ 0.125) | ≈ 24 Nm |
|---|---|
| Class 10.9 (dry, ~µ 0.125) | ≈ 36 Nm |
| Class 12.9 (dry, ~µ 0.125) | ≈ 42 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 M8
| Tensile stress area As (ISO 724) | 36.6 mm² |
|---|---|
| Proof load, class 8.8 | 21 kN |
| Proof load, class 10.9 | 30 kN |
| Proof load, class 12.9 | 36 kN |
| Min. ultimate tensile load, class 8.8 | 29 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.
M8 Phillips Oval Countersunk Head Machine Screws, Metric Weight
A steel M8 phillips oval countersunk head machine screws, metric at the listed 1,060 mm length weighs approximately 1,956 g each — about 1,956 kg per 1,000 pieces. Stainless A2/A4 weighs roughly the same (density 7.9–8.0 g/cm³).
Actual weight varies slightly with head form, thread and finish; use this figure for freight estimation only.
Mating Parts for M8
For M8, pair with a M8 hex nut (ISO 4032 / DIN 934) and, where used, a M8 flat washer (ISO 7089 / DIN 125A) under the head and under the nut.
When to Step Up or Down from M8
When the joint preload approaches the proof load of M8 class 8.8, step up to M10 class 8.8 (or move to M8 class 10.9). When the joint is over-specified, M6 often saves weight and cost without losing the safety margin.
Custom manufacturing · Made to drawing
Need phillips oval countersunk head machine screws, metric in a size this table does not list?
This page covers M8 phillips oval countersunk head machine screws, metric. Thread size and pitch, length, property class, drive form, head geometry and head marking are all specifiable — the standard part is where it starts, not where it stops. Made by cold heading or warm forging.
Minimum order from 2,000 pieces; samples within 7 days of drawing approval.
