Alloy Steel Knurled Cup Point Socket Set Screws

A standard cup point holds by biting into the shaft. The knurled cup point does that and then adds a second mechanism: serrations cut around the rim of the cup that embed themselves into the mating surface as the screw seats. Those teeth resist rotation — specifically, the slow reverse rotation that vibration works on every threaded fastener. Under sustained shake, a plain set screw can walk itself loose a fraction of a degree at a time; the knurled cup's serrations act like a ratchet against exactly that motion. It's the closest thing to a self-locking set screw that doesn't involve a nylon patch or threadlocker, which is why it's the default pick for conveyor systems, packaging machinery, vibratory equipment, power-transmission components, and any collar, gear, sprocket, or pulley that lives on a machine that never stops shaking.

The rest of the format is standard socket set screw: headless, so the installed fastener sits within or below the surrounding surface, driven by an internal hex socket that works inside compact assemblies. Alloy steel construction backs the point with the hardness the serrations need to embed rather than flatten.

Two honest boundaries. First: those serrations hold by digging in, which makes this the most surface-aggressive point in the set screw family — it will leave a pronounced witness mark, so it has no business on a ground, polished, or coated shaft; that's what our nylon tip and brass tip set screws exist for. Second: this is a set-and-leave fastener. Every removal and re-seating cuts a fresh ring of marks and dulls the old grip, so for assemblies that get repositioned regularly, a plain cup point — or a soft-tip screw — is the better tool. Point geometry isn't interchangeable; each style creates a different contact condition, and the knurled cup earns its place specifically where vibration is the enemy and the shaft surface is expendable.

Cold Headers supplies alloy steel knurled cup point socket set screws in a range of inch thread sizes and lengths, including the uncommon and difficult-to-source configurations this niche point style is known for. Individual product pages list exact thread size, length, hex socket size, and point dimensions. If the size you need isn't shown, there's a good chance we can quote or supply it.

Call 773-775-7900 or email Sales@coldheaders.com for pricing, availability, or a quote.