Next: Shear Screws (Security Snap Off Screw) 
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Security shear nuts, also known as breakaway nuts, snap off nuts or permacone nuts, are a premium 1-way permanent security solution ideal where maintenance is not required.
Designed to prevent unauthorised tampering or removal of equipment or facilities, breakaway nuts are typically used in public areas (schools, hospitals etc) and within the fencing industry, e.g. for security perimeter fencing, and the automotive industry. Can be used anywhere where a permanent fixing is needed.
- One of the best 1-way security solutions available
- Breakaway hex nut and cone shaped permanent nut
- Suitable for high torque applications
- Vibration resistant
- Tightened using standard spanner or socket
The hexagon nut section is fully tightened with a standard spanner or socket until the pressure applied surpasses the maximum torque limit, which causes the hexagonal part of the nut to break off, leaving a plain tamper resistant cone shape which is extremely difficult to remove as there is nothing to grip.
Security shear nuts are available from Fastenright in Steel Zinc plated, A2 and A4 stainless Steel or Galvanised mild Steel.
Non-standard sizes and materials are available to order as specials, including custom parts made to drawings.
| Metric Technical Information | |||||||||||||||
| Bright Zinc Plated | A2 & A4 Stainless Steel | Galvanised | |||||||||||||
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| AF | B | C | D | AF | B | C | D | AF | B | C | D | ||||
| M4 | N/A | N/A | N/A | N/A | 7.0 | N/A | N/A | N/A | N/A | N/A | N/A | N/A | |||
| M5 | N/A | N/A | N/A | N/A | 8.0 – 10.0 | 9.8 | N/A | 4.7 – 6.3 | N/A | N/A | N/A | N/A | |||
| M6 | 14.0 | 13.9 | 0.5 | 7.2 | 10.0 – 13.0 | 9.8 – 12.8 | N/A | 5.5 – 6.0 | N/A | N/A | N/A | N/A | |||
| M8 | 16.0 | 15.8 | 0.5 | 7.6 | 13.0 – 17.0 | 12.8 – 16.8 | N/A | 6.0 – 8.0 | 17.0 | 16.8 | N/A | 7.2 | |||
| M10 | 19.0 | 18. | 1.0 | 8.8 | 17.0 – 19.0 | 16.8 – 18.8 | N/A | 7.5 – 10.0 | 19.0 | 18.9 | N/A | 9.2 | |||
| M12 | 22.0 | 21.9 | 1.0 | 9.9 | 19.0 – 22.0 | 18.6 – 21.8 | N/A | 8.0 – 10.5 | 22.0 | 21.9 | N/A | 9.2 | |||
| M14 | N/A | N/A | N/A | N/A | 22.0 | 21.8 | N/A | 9.0 – 12.5 | N/A | N/A | N/A | N/A | |||
| M16 | 24.0 | 23.8 | 1.0 | 11.5 | 24.0 | 23.8 – 24.0 | N/A | 10.5 – 15.0 | 24.0 | 23.8 | N/A | 11.5 | |||
| M20 | 32.0 | 31.8 | 2.8 | 19.0 | 30.0 | 29.7 – 30.0 | N/A | 18.0 – 19.0 | 32.0 | 31.8 | 2.9 | 18.8 | |||
| M24 | 36.0 | 38.0 | 2.6 | 16.0 | N/A | N/A | N/A | N/A | 36.0 | 38.0 | 2.6 | 16.0 | |||
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| Material / Size | M4 | M5 | M6 | M8 | M10 | M12 | M14 | M16 | M20 | M24 | |||||
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| Imperial Available Sizes | |||||||||||||||
| Material / Size | 10-24 | 1/4″-20 | 5/16″-18 | 3/8″-16 | 1/2″-13 | 5/8″-11 | |||||||||
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| = Available Size not listed? Please make an enquiry – we may be able to provide it. |
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Introducing our patented premium security screw the "Tricone®".