Engineering Information, Conversions and Calculations

TYPE

DIAGRAM

DESCRIPTION

HEXAGON

This is a very common head form, not as popular as the hexagon socket as they take up more space. Hexagon head drive is better than square drive for locations where surrounding obstacles limit spanner access, because smaller spanner swing arcs can still successfully rotate the fastener.

PENTAGON

Not considered a secure head type, as they can be driven using pliers. Can be made more secure if fitted to a counterbore. Standard sockets cannot be used.

SQUARE

Probably the oldest of all fastener heads, has fallen out of favour compared to hexagon heads due to the better spanner access and swing arcs. Mainly produced to replicate existing bolts and screws.

HEXAGON SOCKET

Probably the most common of all fastener heads, hexagon heads are also very old.

HEXAGON SOCKET WITH PIN

A more tamperproof version of the standard hexagon socket.

SOCKET 4 SPLINE or BRISTOL

The main advantage to this drive system is that almost all of the turning force is applied at right angles to the fastener spline face, which reduces the possibility of stripping the fastener. For this reason Bristol screw drives are often used in softer, non-ferrous metals.

SOCKET 6 SPLINE or BRISTOL

The main advantage to this drive system is that almost all of the turning force is applied at right angles to the fastener spline face, which reduces the possibility of stripping the fastener. For this reason Bristol screw drives are often used in softer, non-ferrous metals.

DOUBLE POINT

Double Hex is a fastener specification. It is physically similar but incompatible with triple square and spline drive fasteners. Standard hex keys are compatible as drivers for double hex screws and bolts.

TORX

Torx® was developed in 1965 by Camcar and is the trademark for a type of screw head characterized by a 6-point star-shaped recess. The generic name is hexalobular internal driving feature and is standardized by the International Organization for Standardization as ISO 10664.

TORX WITH PIN

The Tamper Pin TX Security Screw as its name states has an internal pin within the 6-lobe socket (star drive) of the head, requiring a special insert bit or key wrench to insert and remove. This unique feature renders the Tamper Pin TX Screw tamper proof, reducing the risk of vandals or intruders tampering or undoing the screws. Bits are now readily available.

EXTERNAL TORX

An external E-Torx® version exists, where the screw head has the shape of a Torx® screwdriver bit, and a special Torx® socket is used to drive it. These are found primarily on automobile engines. These drive screws and bits are available in both 5 and 6 lobe designs.

PENTALOBE

The pentalobe screw drive is a five-pointed tamper-resistant system being used by Apple in its products. Officially, the security screw is called "Pentalobular security screws" by Apple.

SLOTTED

The slot screw drive has a single slot in the fastener head and is driven by a flat-bladed screwdriver. It was the first type of screw drive to be developed, and for centuries it was the simplest and cheapest to make.

SQUARE SOCKET (ROBERTSON)

A Robertson, also known as a square screw drive has a square-shaped socket in the screw head and a square protrusion on the tool. Both the tool and the socket have a taper, which makes inserting the tool easier, and also tends to help keep the screw on the tool tip without the user needing to hold it there.

DOUBLE SQUARE

An improved version of the standard square drive, being able to be caught by the driver with more frequency.

TRIPLE SQUARE

An improved version of the standard square drive, being able to be caught by the driver with more frequency.

TRIANGLE or TA

The TA is a type of screw drive that uses a triangle-shaped recess in the screw head. Note that the sides of the triangle are straight, which differs from TP3 fasteners.

SQUARE SOCKET (ROBERTSON) AND SLOTTED

As the Robertson head but with added advantage of a slot, for driving without a square bit.

FREARSON

The Frearson screw drive, also known as the Reed and Prince screw drive, is similar to a Phillips but the Frearson has a more pointed 75° V shape. One advantage over the Phillips drive is that one driver or bit fits all screw sizes.

POSIDRIV

Pozidriv® was jointly patented by the Phillips Screw Company and American Screw Company in the USA. The proper Pozidriv® screws have a flatter bottom to the socket, and steeper sides, so the driver doesn't camout as easily. The name is thought to be an abbreviation of positive drive.

POSIDRIV SECURE

A more secure version of the standard Pozidriv® head, with the added centre pin.

MORTORQ

The Mortorq® drive, developed by the by Phillips®, is a format used in automotive and aerospace applications. It is designed to be a lightweight, low-profile and high-strength drive, with full contact over the entire recess wing reducing risk of stripping.

MORTORQ SUPER

The Mortorq® Spiral Drive recess developed by Phillips®, is much shallower than other standard recesses on the market, and can be put into a much shallower head without affecting the strength of the screw.

TRI-WING

The tri-wing, also known as triangular slotted, is a screw with three slotted "wings" and a small triangular hole in the center. Can only be driven with the specific driver. Developed by Phillips®.

TORQ-SET

As its name implies, the TORQ-SET® Offset Cruciform Drive System features an offset cruciform configuration that provides greater strength than a cruciform design, ensuring superior torque tightness for today's demanding applications. Developed by Phillips®.

TP3

TP3 is a type of screw drive that uses a Reuleaux Triangle-shaped recess in the screw head.

OPSIT

Opsit™ is a reverse thread sheet metal screw that installs counter-clockwise, thus, tightens if removal is attempted.

CLUTCH

Due to the design of the vandal resistant Clutch Head Security Screw it is suitable for medium torque applications and is 1 way - Permanent Fixing. The unique drive system has a special chamfer at either side of the slotted drive enabling the screws to be turned in only one direction, so when turned anticlockwise the tool simply slips out.
The clutch head security screw is most commonly seen in public areas such as commercial toilet facilities, where maintenance is not required but security is essential to prevent vandals tampering.

SYSTEM ZERO

The tamper resistant E-6 Drive security screw has unique external, non-slip drive built into the head, which helps avoid damage to adjacent components, requiring a special insert bit or key wrench to insert and remove.Tamper resistant E-6 Drive security screws offer a medium security resistance against vandals and thieves at a relatively low cost, proving an economic and secure equilibrium.

KINMAR

The security Kinmar® bolt's drive is a patented design having unique indentations in the rounded shape of the head providing both security and high torque. Due to the security drive design of the vandal resistant tamper security Kinmar® bolts it is suitable for higher torque applications and is a 2 way removable fixing and offers a premium security resistance against vandals and thieves, making it the ideal security fastener for applications where the highest level of security is essential and maintenance is required, used in security fencing, street furniture, public transport, playgrounds etc.

4 HOLE

The 4 Hole Security Bolts Screws have 4 location holes in the head section that are surrounded by a slim circular groove, requiring a special tool to tighten or remove the 4 Hole screw. This unique feature renders the 4 Hole Security Screw tamper proof, reducing the risk of vandals or intruders tampering or undoing the screws.

WAVE

The security wave bolt's drive is a patented design and is manufactured by the patent holder in the UK, the drive itself is designed with varying angles and radiuses that resist against grips such as pliers. The special security wave tool can be stamped and registered with a customer specific reference number, which ensures that when used on site each individual tool can be tracked and the personnel using the tool can also be registered against the tool for further traceability. In addition the actual distribution of the tool is restricted to manufacturers and installers.

TRI-HEAD

The Tri Head Security Screw has a unique deep triangular head with a flange that requiring a special key wrench to insert and remove. This unique feature renders the tamper resistant Tri Heads security screw tamper proof, reducing the risk of vandals or intruders tampering with or undoing the screws. Due to the security head design of the vandal resistant tamper Tri Head security screw it is suitable for higher torque applications and is a 2 way reusable fixings making it the ideal security fastener for applications where maintenance is required.

OVAL

The Oval Pan Head Security Screw has a unique head that requires special matching driver to insert and remove. As its name states the head of this clever security screws is oval which enables the tool to grip the head and achieve adequate torque. This unique feature renders the Oval Pan Head Security Screw tamper proof, reducing the risk of vandals or intruders tampering or undoing the screws. When applied this product gives a deceptive appearance to would be vandals, looking like a stud or rivet.

SNAKE EYE

Due to the security drive design of the vandal resistant tamper 2 Hole security screw it is suitable for low to medium torque applications and is a 2 way reusable fixings making it the ideal security fastener for applications where maintenance is required.
The two pin drive is designed mainly to offer some security but mainly to maintain the aesthetics of the application it is been used with.

BRYCE KEY-REX

Key-Rex™ fasteners are the world's most secure, tamper-proof screws and bolts on the market. Key-Rex™ is proprietary to Bryce Fastener and configured to keep Torx®-Pin, Hex-Pin™ and other tamper-resistant bits out. Bryce Fastener retails exclusive rights and control over the restricted screws and drive, making these very secure from tamper and vandals.

BRYCE PENTA

Vandal proof and tamper resistant screws.

BRYCE PENTA PLUS

Bryce Fastener retails exclusive rights and control over the restricted screws and drive, making these very secure from tamper and vandals.