STAINLESS STEEL HEXALOBULAR CAP SCREWS ISO 14579

Hexalobular Cap Screws ISO 14579 — Hexalobular cap screws share the same cylindrical head and body proportions as a standard DIN 912 socket cap screw, but replace the plain hex socket with a six-lobed recess defined by ISO 14579 — a standard that fixes not just the head geometry (which mirrors the hex socket range) but the shape and depth of the lobed drive itself, ensuring a consistent fit with the matching size of hexalobular bit. The lobed profile spreads contact across six points rather than six flat faces, which matters most where tightening is done by a powered driver rather than a hand-held Allen key: automated and semi-automated assembly lines, high-volume production work, and any setting where consistent, repeatable torque delivery without cam-out is more valuable than the marginal cost saving of a plain hex socket screw.

Grade selection follows the same logic as any other stainless socket screw: A2 covers the majority of indoor, low-corrosion-risk assemblies at a lower cost, while A4 is worth specifying where the finished product will be exposed to salt, washdown chemicals, or sustained moisture — food and beverage machinery, marine equipment, and outdoor plant are typical A4 territory. Because these screws are so often used in automated, high-throughput settings, consistency of supply and grade matters as much as the grade itself: mixing A2 and A4 batches on the same production run risks inconsistent corrosion performance across a batch of otherwise identical-looking parts.

Sizing follows the same rules as any hex-socket-derived cap screw: choose a diameter for the load the joint carries, and a length that gives full thread engagement in the tapped hole (more in aluminium or plastic than in steel). The one extra consideration specific to this drive type is matching the bit: hexalobular sizes are denoted with a T-number rather than a hex across-flats dimension, so drawings and toolkits need to reference the correct T-size rather than assuming a hex key from the equivalent-diameter cap screw will fit — it won't.

FAQs
Are hexalobular cap screws interchangeable with DIN 912 socket cap screws?
The head and body dimensions correspond to the same family of hex socket cap screws, so they occupy the same counterbore and clearance-hole envelope. Only the drive recess and the bit/key required differ.

Why choose a hexalobular drive over a hex socket, beyond cam-out resistance?
On high-volume or automated lines, a rounded-out hex socket means a scrapped or hand-finished part; a hexalobular recess holds its shape over far more tightening cycles, which reduces both scrap and bit wear over the life of a production run.

Can a standard Allen key be used to drive a hexalobular cap screw?
No — the six-lobed recess needs a matching hexalobular (Torx-type) bit or key; an Allen key will not seat correctly and risks slipping and damaging the recess.