Pan Head
Slotted pan has a flat or gently rounded top surface, cylindrical sides and a flat bearing surface. Phillips pan has a rounded top, cylindrical sides and a flat bearing surface. Has a general purpose bearing area. Can be substituted in most applications for round, truss or binding heads
Round Head
Has a semi-elliptical top surface and a flat bearing surface. Sometimes preferred over pan head for its smooth surface and appearance.
Truss Head
Has a low rounded top surface with a flat bearing surface greater in area than a round-head screw of the same nominal size. Weaker than pan or round heads but preferred in applications where minimal clearance exists above the head. Truss profile provides a trim, finished assembly appearance.
Fillister Head
Has a rounded top surface, cylindrical sides and a flat bearing surface. The greater side height is what distinguishes a fillister head from a pan head. Preferred style for use in counter bored holes
Flat 82° Head
A countersunk head with a flat top surface and a cone-shaped bearing surface with a head angle of approximately 82°. Used in applications where protrusion of the fastener above the mating surface is unacceptable. Use a protrusion gage when measuring head height.
Flat 100° Head
A countersunk head with a flat top surface and a cone-shaped bearing surface with a head angle of approximately 100°. Preferred over an 82° flat head when fastening in soft materials—the 100° countersunk head distributes pressure over a larger surface area.
Flat Undercut Head
Similar to an 82° flat head except that the head is undercut to 70% of its normal side height. Standard for short lengths because it allows greater length of threads. Also avoids transition fillet and assembly interference.
Oval Head
A countersunk head with a rounded top surface and a cone-shaped bearing surface of
approximately 82°. Preferred over a flat head in conical applications, or when a more decorative finished look is desired. Countersunk surface nests into mating countersunk application sites.Indented Hex Head
Has an indented top surface, six flat sides and a flat bearing surface. Preferred in high volume assembly where pneumatic equipment is used to drive the screw. Can transmit significantly higher tightening torque levels than other head styles.
Indented Hex Washer Head
Has an indented top surface, six flat sides and a flat washer which projects beyond the sides and provides a flat bearing surface. The washer and hex head are formed together as one piece. Offers greater protection to the mating surface than a standard indented hex head. Increased bearing area reduces likelihood of crushing mating surfaces.
