Set Screws Cup Point
What are Set Screws Cup Point?
Cup point set screws are headless fasteners with a hollow, radiused tip that bites into the mating surface. The cup profile concentrates clamp force for secure holding with moderate surface marking, making them the go-to choice for collars, pulleys, and general machinery on round shafts.
Why choose Set Screws Cup Point
- Strong bite — cup edge digs in to resist slip and vibration.
- Low-profile — headless, flush fit for tight spaces and clean assemblies.
- Serviceable — hex-socket drives allow precise torque in confined locations.
- Versatile — works on shafts with or without a machined flat.
Common applications for Set Screws Cup Point
- Securing collars, gears, sprockets, and pulleys on round shafts
- Positioning knobs and handles on flats
- Fixtures, jigs, instruments, and general machinery
Materials and finishes for Set Screws Cup Point
- Alloy steel black oxide for high strength in dry interiors.
- 18-8 / 304 stainless for broad corrosion resistance.
- 316 stainless for coastal/marine or chloride exposure.
How to size and specify Set Screws Cup Point
Order by diameter × thread × overall length (e.g., 10-32 × 3/16″, 1/4″-20 × 3/8″, M6-1.0 × 8 mm). Match thread standard (UNC/UNF or metric ISO) to your tapped hole.
How Cup Point Set Screws compare to other point styles
- Cup vs knurled cup — knurled adds serrations for extra bite under vibration.
- Cup vs flat — flat minimizes marring on a machined flat and suits frequent adjustment.
- Cup vs cone — cone penetrates deeper for the strongest location.
- Cup vs dog / half-dog — dog points index into a hole/slot for positive positioning.
Installation tips for Set Screws Cup Point
- Use the correct hex key fully seated; tighten to recommended torque.
- If possible, add a small flat on the shaft to increase anti-slip resistance.
- Apply threadlocker or a jam set screw where vibration is present.
Set Screws Cup Point FAQs
See the accordion below for quick answers on selection, sizing, torque, and when to choose cup points over other styles.
Note — Guidance here is general. Always follow your product datasheet and project specifications.
General-purpose locking on round shafts, collars, pulleys, and gears, where a strong bite and a flush, headless profile are needed.
Use standard cup for strong grip with moderate surface marking, knurled cup for extra bite under vibration, and flat where you want minimal marring on a machined flat.
Order by diameter × thread × overall length (e.g., 1/4″-20 × 3/8″ or M6-1.0 × 8 mm) to match your tapped hole depth and required engagement.
Black-oxide alloy for high strength in dry interiors; 18-8/304 for general corrosion resistance; 316 for marine or chloride exposure.
Recommended for vibration. Alternatively, add a second jam set screw to lock the first.
It will mark the surface slightly as it bites. Use a machined flat, choose a flat-point screw, or use a soft-tip style if shaft finish must be protected.
Follow torque guidance for the screw size and material. Tighten until secure; avoid over-torque that can strip threads or deform the shaft surface.