This page covers M8 Thin Hex Castle Nut to GB/T 6181 / ISO 4035: the full dimensional row, hole and tool sizes, proof-load data and typical applications. All values are taken from the governing standards (GB/T 6181 / ISO 4035 together with ISO 273, ISO 724 and ISO 898-1 where applicable).
M8 Dimensional Row (GB/T 6181 / ISO 4035)
| Size | Pitch (mm) | Width across flats s (mm) | Width across corners e (mm) | Total height m (mm) | Slot width (mm) | Reference standard |
|---|---|---|---|---|---|---|
| M8 | 1.25 | 13.0 | 14.38 | 9.8 | 2.5 | ISO 7036 / GB/T 6180 |
Spanner & Drive for M8 Thin Hex Castle Nut — GB/T 6181 / ISO 4035 (Series 053)
Drive geometry for M8 Thin Hex Castle Nut — GB/T 6181 / ISO 4035 (Series 053) is given by the row above; match the tool to the listed values.
Common Applications for M8 Thin Hex Castle Nut — GB/T 6181 / ISO 4035 (Series 053)
M8 Thin Hex Castle Nut — GB/T 6181 / ISO 4035 (Series 053) are commonly specified for general-purpose joints in machinery, fixturing and equipment frames.
Mating Parts for M8
Pair M8 with the matching M8 bolt or screw, plus a M8 flat washer where required to distribute load on softer materials.
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.