Shear Nuts | Security Breakaway Nuts

Shear Nuts (Security Breakaway Nuts)

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.

	Bright Zinc Plated				A2 & A4 Stainless Steel				Galvanised
Metric Technical Information
	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

Material / Size	M4	M5	M6	M8	M10	M12	M14	M16	M20	M24
Metric Available Sizes
BZP Steel
Galvanised
A2 Stainless Steel
A4 Stainless Steel
= Available Size not listed? Please make an enquiry – we may be able to provide it.