This page covers M8 SEMS Screws with Captive Spring Washer to DIN 6900-4: the full dimensional row, hole and tool sizes, proof-load data and typical applications. All values are taken from the governing standards (DIN 6900-4 together with ISO 273, ISO 724 and ISO 898-1 where applicable).
M8 Dimensional Row (DIN 6900-4)
| Thread size | Pitch (mm) | Head diameter dk (mm) | Head height k (mm) | Washer outer diameter (mm) | Cross recess | Common length range (mm) | Reference standard |
|---|---|---|---|---|---|---|---|
| M8 | 1.25 | 16.0 | 6.0 | 15.4 | PH4 / PZ4 | 10~60 | DIN 6900-4 |
Spanner & Drive for M8 SEMS Screws with Captive Spring Washer
Drive geometry for M8 SEMS Screws with Captive Spring Washer 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 | 6.8 mm |
Tightening Torque for M8
| Class 8.8 (dry, ~µ 0.125) | ≈ 25 Nm |
|---|---|
| Class 10.9 (dry, ~µ 0.125) | ≈ 35 Nm |
| Class 12.9 (dry, ~µ 0.125) | ≈ 41 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 898-1) | 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, class 8.8 | 29 kN |
Proof load = stress area × proof stress per ISO 898-1. Design joints so the working preload stays below the proof load of the selected class.
M8 SEMS Screws with Captive Spring Washer Weight
A steel M8 sems screws with captive spring washer at the listed 1,060 mm length weighs approximately 1,673 g each — about 1,673 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.
Common Applications for M8 SEMS Screws with Captive Spring Washer
M8 SEMS Screws with Captive Spring Washer are commonly specified for machine assembly, general engineering, plant maintenance and OEM equipment.
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.
