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Sentinel Countersunk Security Machine Screw

Sentinel security screws – countersunk head

Countersunk head sentinel screws have a unique head which can only be turned one-way, so once securely tightened, they are very difficult to remove.
Sentinel security screws are installed using only a standard cross head or pozi driver. Quick to install with screwdrivers or power drivers, these are a popular choice for installers and for large volume applications.

  • 1-way permanent security fixing
  • Tamper-proof for use where maintenance is not required
  • Countersunk head security screw
  • Suitable for high torque applications
  • Good for use with power drivers
  • Typically used in prisons, public facilities and toilets and for industrial roofing

Countersunk head security machine screws

The Sentinel drive offers medium security resistance against vandals and thieves at a relatively low cost. An adaptation of the original Nettlefolds ‘Pozi’ drive, designed to provide a secure and permanent fixing, and can be used in high volume, inserted with a power tool.
With high resistance to cam-out, Sentinel screws are a preferred choice for applications requiring high volume, labour intensive work.

Sentinel countersunk machine screws can be used with security Wave Nuts, Shear Nuts, Kinmar Reusable Nuts, Kinmar Permanent Nuts, 4-Hole Nuts or Pin Torx Barrel Nuts for added security.

Available from stock in zinc plate, with other sizes and materials available to order.
Specials made to order, including medium / high volume manufacture, modifications and custom parts to drawings – please enquire.

Thread / Length (mm) 12 16 20 25 30 40

Sentinel countersunk machine screw technical drawing

M4 M5 M6
DK (mm) 7.2 8.9 10.8
K (mm) 2.7 3.0 3.6

*For guidance purposes only

Sentinel Countersunk Security Screws