Description
Button Head Hexalobular Socket Screw M4 x 8, Steel Grade 8.8, Zinc Plated, Full Thread — BOLTON SKU 55349.
About the Button Head Hexalobular Socket Screw M4
This Button Head Hexalobular Socket Screw M4 size combines a low, domed button head with a hexalobular internal drive — the six-lobe recess geometry standardised in ISO 10664, commonly known by the Torx pattern. It carries the standard metric coarse thread for M4 (0.7 mm pitch), is 8 mm long and fully threaded, and is made from steel in property class 8.8 with a zinc-plated finish. Compared with a plain hexagon socket, the six-lobe drive transfers torque through a larger contact area with near-zero cam-out, reducing bit wear and recess damage in repeated or driver-based assembly. The wide dome head spreads bearing load and leaves a rounded, snag-free surface, while the zinc plating provides sacrificial corrosion protection for the class 8.8 carbon-steel body in dry and sheltered service.
Key specifications
| Thread | M4 × 0.7 (metric coarse) |
|---|---|
| Length | 8 mm, full thread |
| Head style | Button (dome) head, low profile |
| Drive | Hexalobular (six-lobe) internal, ISO 10664 geometry |
| Material | Steel, property class 8.8 |
| Finish | Zinc plated |
Typical applications
Class 8.8 hexalobular button screws in M4 × 8 are production-line fasteners: fixing covers, trims, brackets and guards on machinery and vehicle equipment where powered drivers are used and recess durability matters. The zinc-plated 8.8 specification suits load-bearing small joints in dry or sheltered service.
Supplied by BOLTON Technical Equipment Supplies against request for quotation. Add this item to your RFQ basket to request pricing, lead time and documentation requirements (e.g. CoC, datasheets or test reports where applicable).
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