Header fastener image

Security Fasteners and General Fixings from Stock and to order

Click Now for a Quote

Call +44(0) 1902 457734

Twitter Icon Facebook Icon LinkedIn Icon Skype Icon

Clutch Head Security Barrel Nuts & Sex Bolts

Tamper Proof Clutch Head Security Sex Bolts Protect Against Vandals and Thieves, Offering:

  • Medium Security Resistance
  • Permanent one-way drive
  • Usable for medium torque applications
  • Ideal for use in architectural staircasing and balustrading

A security sex bolt is a tamper-proof adaptation of the commonly known sex bolt, also known as a barrel nut, barrel bolt, Chicago screw, architectural bolts or post and screw.

This is a type of tamper-proof security fastener which has a barrel-shaped flange and protruding boss that is internally threaded. The boss sits within the components being fastened, and the flange provides the bearing surface.

The security sex bolts, including a male and female bolt, and the accompanying tamper-proof security machine screw sit flush on either side of the surfaces being fastened.

It is often chosen because of its low profile compared to other fasteners. It has a built-in security drive feature to aid in tightening the fastener.

They can also be referred to as a sleeve nut within the industry.

  • Male screws are available with or without shoulders.
  • All parts are matched for a finished appearance.
  • Both female and male bolts feature the security drive.
  • Head dimensions for both male and female parts are matched.
  • Button Head, Truss Head and Countersunk head available.
  • Made to individual customer requirements.
  • Can be manufactured in steel or stainless steel.

Please contact us with your requirements to further your enquiry.

Gauge / Length 1/2″ 5/8″
10-24 UNC Marker-image Marker-image


Clutch head barrel nuts technical drawing

10-24 UNC A (mm) B (mm) C (mm)
1/2″ 10.9< 12.6< 6.3<
5/8″ 10.9< 15.9< 6.3<

*For guidance purposes only

Clutch Head One Way Barrel NutClutch Head One Way Male ScrewClutch Head One Way Sex Bolt Sets