Fastener Head Shapes

Head shapes, or head forms refer to the shape of the top of the screw. This guide shows you all the different types of head form, and their potential uses.

How to measure the diameter and length of a standard fastener
Head Shape Usage
Flat / Countersunk A flat or countersunk headed screw sits flush with the material being fixed, and is used when the application requires the screw doesn't protrude from the material it's fixing.
Oval Very similar in application to a countersunk head, an oval headed screw is slightly rounded and in some applications looks better aesthetically.
Pan A pan head screw gets its name as it has a similar shape to the bottom of a pan. The high sides allows for a deep socket or slot, making it easier to tighten.
Truss A truss head screw is sometimes referred to as a mushroom head. It is shallower than most other head types, and also covers a larger surface area.
Round A more rounded head shape with a flat bottom, a round head screw sits above the material being fixed. Typically paired with a slotted or pozi drive type.
Hexagon Hexagon headed screws are characterised by their six-sided head shape. They are very popular as they are extremely versatile and can be tightened and loosened easily from all angles.
Hexagon Flange Hegagon flange screws are similarly shaped to hexagon screws, but incorporate a flanged base which negates the requiement to use a washer.
Slotted Hexagon Flange Similar to the hexagon flange head, but also incorporates a slot on the top so the screw can also be tightened with a screwdriver.
Socket A cylindrical head with a hex key socket (sometimes known as an Allen key) used for tightening and loosening.
Button Very similar in shape to a round headed screw, but tends to be paired with a socket drive type.