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
A 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.
A 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.
