FASTENERS 101™
Drives, Heads and Threads


Fastener Variety Specifics

Fasteners come in various different drive styles, each offering its own benefit to a specific application. Additionally, the head and the thread of the fastener also offer the same specifications depending upon application type.

Fastener Drives Fastener Heads Fastener Threads


Drives

There are several more drive styles available, these are the styles that you will currently find on our site. Coming soon: Spanner, HTC / One Way, Clutch, Tri-Wing & More!

phillips drive

PHILLIPS

The most common drive style. Shaped like a cross.

slotted drive

SLOTTED

A straight line cut into the center of the head.

SlottedPhillips combo Drive

SLOTTED/PHILLIPS COMBO

A drive style combining the two most popular drives for ease of use with whatever tools you have available.

square drive

SQUARE

A square shape, resists stripping out.

torx

TORX / STAR / 6 LOBE

Torx drive, also known as star drive resists stripping out and provides a more decorative drive finish.

Torx Security Screw

TORX WITH PIN / TORX TAMPER PROOF / TORX SECURITY

Torx with pin security drive can only be driven with security bits and are used to prevent tampering and theft.

SOCKET HEAD SCREW

SOCKET / ALLEN / HEX

Driven with an Allen Key, hex wrench or socket driver, socket caps are often used for decorative or automotive applications.

SOCKET / ALLEN / HEX WITH PIN SECURITY drive

SOCKET / ALLEN / HEX WITH PIN SECURITY

Driven with a specia security Allen Key, hex wrench or socket driver, socket set are often used for flush or secure finish.

External Hex Head Drive

EXTERNAL HEX HEAD

While not technically a drive style, the hexagonal head is designed to be driven by a wrench.

One Way security screws

ONE WAY SECURITY

The one way security drive style is driven in using a flat head screwdriver and cannot be easily removed.

Spanner Security Drive

SPANNER SECURITY DRIVE

Driven using a special two point bit, also referred to as a snake eye drive.


Heads

The most common fastener heads are listed for your convenience.

bugle head

Bugle Head

A Bugle Head is similar to a flat head. This screw has a rounded section that will pull down the material instead of cutting through it as it is fastened. Distributing the pressure over a larger surface area.

button head

Button Head

A button head is a rounded head, used primarialy in socket cap screws. This head sits above the installation surface.

Button Flange

Button Flange

The button flange head is similar to the regular button head style but with a flange or integrated washer to increase surface area during an installation.

cup (dome) head

Dome (Cup) Head

The cup head is seen almost exclusively on carriage bolts. With a square neck, this head style is made to be pulled into soft material, such as wood, and hold the bolt in place.

Fillister Head

Fillister Head

A head with a higher profile than a round head or button head. This type of screw also has a deeper drive area and is commonly used in countersunk holes.

External Hex Head

External Hex Head

External hex heads are the standard bolt head. This head is designed to be driven by a wrench and allows for high torque installations.

Hex Washer Head

Hex Washer Head

A head that is designed to be driven by a wrench with an integrated washer or flange to increase the installation surface area.

Knurled Cap

Knurled Cap

A knurled cap head style sits above the installation surface and has indents on the sides to be gripped by the thumb.

Knurled Thumb

Knurled Thumb

A knurled cap head style sits above the installation surface and has indents on the sides to be gripped by the thumb.

Smooth Cap Head

Smooth Cap Head

Similar to a knurled cap head style but designed to be driven by an allen wrench or hex key. The smooth sides give it a cleaner finished look.

No Head

No Head

The head of a socket set screw, lacks a head and has an internal drive in the body of the screw itself. Designed to sit flush with the installation surface.

Flat Head

Flat Head

A flat head is can have a number of drive styles, designed to be drilled into a material until it sits flush with the installation surface.

Oval Head

Oval Head

Similar underside to that of a flat head screw but with a decorative rounded top. Commonly used as a finish screw in visible applications.

Pan Head

Pan Head

A screw with a rounded head (less so than a button or round head) and a flat bottom designed to sit directly on the installation surface.

Pancake Head

Pancake Head

A flat topped screw with a wide head to sit close to flush but also have a large surface area on the installation material for grip.

Round Head

Round Head

A completely rounded head that was very popular but has become less so with the variety of heads now available.

Square Head

Square Head

a head designed to give better grip to a wrench than an external hex head.

Truss Head

Truss Head

With a flat bottom and a wider installation surface area, this screw is used where a lower profile is desired but a strong grip is needed.

Modified Truss Head

Modified Truss Head

Similar to the truss head but with an integrated washer which increases the surface area of the head even more.


Threads

coarse thread screw
COARSE THREAD - UNC

Coarse threads are those with larger pitch (fewer threads per axial distance) and larger thread form relative to screw diameter. Example: 5/16-18

fine thread screw
FINE THREAD - UNF

Fine threads are those with smaller pitch (more threads per axial distance) and a smaller thread form relative to screw diameter. Example: 5/16-24



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