Head Style Guide

Hexagon (or Hex) The most common head on bolt products and also seen on many screw products. Can come in several versions. This one is referred to as full bearing face. The manufacturer has the discretion to supply low tensile products as full bearing face. ISO 4014 AMSE 18.2.1 Hex Flange Head On bolts, correctly termed hex flange head and when used on self-drilling screws, correctly termed hex washer head. Beware not to confuse with hex washer faced. "ISO 4162 (DIN 6921)" IFI 111 Serrated Flange Head A flange head screw with serrations under the head to counter loosening due to vibration. ISO 4162 IFI 111 Indented Hex Head Hex head with an indentation to allow for better drive engagement with less material. ASME B18.6.3 Indented Hex Washer Head Indented hex head with added flange for use with pneumatic installation tools. Called "indented washer head" when used in machine screws. Cap Head Normally incorporating a recess and usually associated with very high tensile products, eg: socket head cap screws. "ISO 4762 (DIN 912)" ASME B18.3 Shoulder Features a precision-ground shoulder for alignment of fastened items. Primarily used for shear loading. ISO 7379 ASME B18.3 Low Head (Low Profile) Features a low profile head for improve clearance. DIN 7984 ASME B18.3 Button Head "Button head cap screws have a low domed head and provide a wide bearing surface. They provide a clean and neat appearance. Button cap screws lack the strength of regular socket cap screws. Typical drives include : Hex Socket and Torx / Hexalobular" ISO 7380 "ASME B18.3 " Button Head with Collar Button head cap screw with additional contact area under head. ISO 7380-2 Round Common screw type with a domed, nearly hemispherical head. ASME B18.6.3 Pan Common screw type with a mushroom-shaped head. ASME B18.6.3 Truss Similar to a pan head screw, but head has a larger diameter. ASME B18.3 Modified Truss "Truss head screw with larger contact area under head. Primarily used for securing lath to wood or metal studs. Extra wide head distributes load to reduce crushing thin metal." " Fillister" Often called a cheese head. Similar to a pan head but has a larger side height. Typically choosen for installation in counterbored holes. ISO 1207 ASME B18.3 Binding A binding head screw is a type of screw that has a small, rounded head with a slightly tapered top surface. It is designed to hold materials together by binding them tightly against the surface to which they are screwed. The binding head allows for a flush surface and can be used in situations where a countersunk screw is not suitable. Similar to a pan head but thicker. Binding head have 10% more load bearing surface than pan head. ASME B18.3 Oval Similar to a countersunk (or flat-head) screw, but with a protruding domed head. Typically as a decorative feature, often in cabinet work. ISO 2010 ASME B18.6.3 Oval Undercut Oval head with relief underneath head. Used for attaching components made of thinner materials such as hinges. ASME B18.6.3 Flat 82° Most common usage is on screw products where a flush fit is required on the surface, eg: door hinges and timber joinery or into steel applications. Angle of head is 82°. ASME B18.3 Flat 100° Flat head, countersunk screw with 100° under head angle. Generally used with soft materials where additional load bearing area is desired. Flat Undercut Undercut heads have a flat bottom under the head as opposed to a conical form to the shank as a flat head. Typically used in door hinge applications. " Bugle" "Most commonly found on self-drilling screws used in plasterboard fixed to timber or steel frames. Designed to self-embed. " Countersink Ribs Counter sunk screw with ribs or nibs under the head to resist loosening. External Hexalobular Flange Normally confined to special high tensile products in high torque applications DIN 34800 Square Head Used for machine bolts and set screws. Excellent engagement with open-end wrenches. ASME 18.2.1 Domed Heaxagon Head (Track Head) Sometimes found on special bolts for engine heads, but more often on earthmoving equipment as crawler track retaining bolts. Tee Head Typically used where rotation of the bolt is restricted, such as in a channel or slot. Wafer Counter sunk screw with a larger head diameter with improved load distribution. Generally used in construction for securing panels made of wood or other soft materials to framework. Round (U-Drive) Intended to be inserted in a thru hole on a thin sheet and driven into a pre-drilled hole. Often used for securing ID or data tags to machinery. Considered a permanent fastener. Carriage Feature a domed head and square or winged shoulder. Used in wood or in metal with a square-punched hole to allow fastening with a single tool. ISO 8678 ASME B18.5 Plow Similar to carraige bolts, but feature a non-protruding head intended to prevent interfering with material that may be sliding against the fastened part. DIN 605 ASME B18.9 Elevator Used in grain elevators or conveyors where protrusions of the bolt head must be avoided. Has a large flat or slightly convex head to avoid snagging. DIN 15237 Weld (U-Type) Projection welded bolt with protrusions under head. Intended to be inserted in a thru hole for welding. Weld (T-Type) Projection welded bolt with protrusions on the top of the head. Intended to be installed directly to mating surface. Sidewalk Feature an ultra-low profile head that reduces tripping hazard when used on platforms or walkways. Tapered Head Head tapers to the top of the head. Offers streamlined aesthetic. Cone Head Head tapers to the top of the head. Offers streamlined aesthetic. Nibs Nibs for self-clinching in press install.