All fasteners are subjected to routine sample test procedures at each key stage of manufacture and also on completion. A pre-determined number of parts per batch are checked for dimensional accuracy against their relative drawing and then destructively tested to ensure that the weld is to the required standard (Fig. 1).

A tensile force is applied and recorded at intervals of baseplate distortion (eg. 0.5mm elongation) and then a final pull-off value is taken. A batch is passed only if a consistant weld integrity rate results in accordance with our strict measurement criteria.

Although values vary depending on the fastener size, the typical recommended torque value on a mid-range M1 (for example) is in the region of 13Nm and the tensile strength (at 0.50mm elongation) is approximately 4.50kN. Tolerances on all of our fasteners are +/-0.25mm (general) and 1.00mm on stud length.