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Clutch Head Round Self Tapping Security Screws

Tamper proof clutch head screws – round head

A permanent, tamper-resistant self-tapping clutch head screw which cuts its own thread, requiring only a slotted screwdriver to fit.

  • One way permanent security screw, medium security resistance
  • Suitable for medium torque applications
  • Unique chamfered drive allows screws to be turned in one direction only
  • Ideal for use in public areas where maintenance is not required
  • Install with standard slotted screwdriver

Available off the shelf in stainless steel with other materials and sizes available to order. All stocked sizes listed below. Sizes not listed, modifications and custom parts are available to order, including small volume manufacture.

Not what you’re looking for? See all security clutch head screws here.

Gauge / Length (mm) 3/8″ (9.5) 1/2″ (13) 5/8″ (16) 3/4″ (19) 1″ (25) 1 1/4″ (32) 1 1/2″ (38) 2″ (50) 2 1/2″ (63) 3″ (75)
No.4 (2.9mm) marker-image marker-image marker-image marker-image
No.6 (3.5mm) marker-image marker-image marker-image marker-image marker-image
No.8 (4.2mm) marker-image marker-image marker-image marker-image marker-image marker-image marker-image
No.10 (4.8mm) marker-image marker-image marker-image marker-image marker-image marker-image marker-image
No.12 (5.5mm) marker-image marker-image marker-image marker-image marker-image marker-image marker-image marker-image
No.14 (6.3mm) marker-image marker-image marker-image marker-image marker-image marker-image marker-image marker-image marker-image

Self tapping clutch head screws

The clutch head security screw has a unique head, requiring only a standard slotted screwdriver for insertion, making this the ideal security screw for one way permanent applications*.

Also referred to as clutch drive, one way screws, one way round screws and perma screws, the design of these screws makes them suitable for medium torque applications, as 1-way permanent fixings. 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.

Mass usage notes:

Although clutch head security screws provide an excellent permanent security solution for mass usage they can be time consuming to install.

Where fast installation is essential, we also offer the Sentinel security screw which utilises a modified pozi drive, allowing standard pozi drill bits to be used for fast and high volume installation.

*Special removal tools are available but are only recommended for use with stainless steel clutch head screws, and are only supplied to account customers who have purchased the corresponding screws. We do not sell removal tools to non-account customers.

Clutch Head pan self tapping screw technical drawing

No.6 No.8 No.10 No.14
DK (mm) 6.3 7.6 8.8 11.7
K (mm) 2.5 2.9 3.4 4.4

*For guidance purposes only

Clutch One Way Round Self Tapping Security Screws