Socket Head Cap Screw – strongest of all head styles.
- Head height is equal to shank diameter.
- Shouldn’t be mated with a regular hex nut, which isn’t as strong.
Low Head Cap Screw – designed for applications with head height limitations
- Head height is approximately half the shank diameter.
Flat Head Cap Screw – for flush applications
Caution: Inch and metric have different countersink angles. Mismatching fastener and hole countersink angles can result in premature fastener failure
Button Head Cap Screw
- Larger head diameter makes it more appropriate for holding thin materials like sheet metal guards.
- Because of its internal hex drive style it’s ideal for tamper-proofing applications.
- Good substitute for other drive styles that are prone to stripping like Phillips and slotted.
Socket Shoulder Screw
- Typically used as a pivot point or axle because shoulders are ground to a tight tolerance.
Thread Class
- Socket head cap screws 1″ diameter and under have class 3A fit (tight tolerance). Over 1″ have a class 2A fit (typical hex cap tolerance).
- All other head styles and diameters have a class 3A fit.