A Beginner’s Guide to Screw Head Types
A screw is a type of fastener characterised by a helical ridge, also known as a male (or external) thread. Typically made of metal, screws fasten materials by digging in and wedging into them by turning, upon torque applied.
There are a variety of screw head types for different materials, and for different applications; screws are often used to fasten sheet metal, wood, and plastic.
The ‘binding’ type is a commonly used screw head type. It is an ideal choice for electrical applications; beneath the head is a prominent undercut area providing space for wire connections.
Binding screws are also used for other kinds of projects; they are often used to hold together large manuals, for bookbinding, and in leather products.
The ‘trim’ screw head is a standard countersunk screw that provides a flat, smooth surface after installation. It is an alternative to flat head screws, with a narrower head a more suitable choice for certain applications. The Flat Trim is often used as a finishing screw for carpentry and woodworking.
The ‘oval undercut’ is ideal for shorter screw lengths which require longer thread grip and more shallow countersinking.
A smaller diameter, in addition to a higher profile, than round or pan heads, makes the ‘fillister’ screw head effective for a deeper slot.
The ‘flat fillister’ is identical to a regular fillister screw, except for a flat top replacing the latter’s oval top.
The Flat 82+ head is used for flush surfaces. They are standard countersunk flat head screws.
Flat 82+ Undercut
The ‘flat undercut’ is very similar to the standard 82-degree head, having the same angle, but a shorter head. This allows it to provide a longer thread on the same screw length.
The Flat 100+ uses a 100-degree angle instead of the standard 82-degree kind. It is an ideal choice for thinner materials that require a flatter head.
Flat 100+ Undercut
The Flat Undercut is used instead of the standard flat head for some short sizes. The 100-degree kind enables more shallow countersinking than standard 82-degree flat heads.
Hex heads allow greater torque to be applied, and are driven with the force working against the outside of the head, unlike other varieties, which are internally driven, They are commonly used for bolts.
The ‘pan’ head is the most commonly used rounded-top screw head. It works well in a range of applications that require a flat-bottomed screw.
The ‘hex washer’ head is an updated, more commonly used version of the hex head. It is characterised by an attached washer style flange under the head, creating a large surface connection area. It is sometimes used in combination drives, with phillips or slotted drives.
It is identical to a flat head, except for its rounded surface. Countersunk screw head that includes a decorative rounded finish at the top. Often used for switch coverings.
The ‘oval trim’ head is the same as the regular ‘oval’ head, but with a smaller diameter and countersink.
The ‘round’ head is less commonly used these days, but it offers a round-surfaced alternative to other screw heads.
It is similar to ‘flat’ heads, but with no driving recess. The ‘round countersunk’ head is used for shorter screw lengths to provide a longer thread grip and more shallow countersinking.
The round washer is a screw head which provides a larger bearing surface in applications where a round head is preferred. It is quite similar to the Modified Truss head style.
Square (Set Screw)
The ‘square’ head is a suitable choice for applications that require more torque. It is most often used for switch coverings
Truss heads are characterized by a curved surface and an extra-wide top. They are often used to prevent tampering., having a lower profile than most round heads
Truss heads are very useful for sheet metal work, insulation, and cabinetry-- an ideal choice for applications that require large holes, as the wide head prevents the screw from going through the hole.
At ITA, we provide a variety of fastener head types to suit your requirements, bringing you quality, expertise, and excellence. To know more, get in touch with us right away!