Looking for anti-vibration, self-locking bolts? Look no further, Unbrako Durlok range is one of the best brands in the industry. Classed as a critical strength application fasteners these are available in metric sizes only starting from M6 going up to M20. Unbrako are best known for their range of socket head caps screws, unbrako pressure plugs and unbrako nuts. All Unbrako socket head caps come complete with ISO 4762.