10Pcs 50mm Hex Screwdriver Bits Set (H3x50)

Hex socket screws — Allen or cap head screws — have a plain six-sided recess, and at 3mm that recess is both small and shallow. That combination is the weakness of the drive, and it is worth understanding because it explains why small hex screws round out so readily. The tool is held only by six flat faces with very little depth, so if the bit is not fully seated it bears on the top millimetre or two of those faces and the corners give way almost immediately under power.

What makes that worse on small screws is that they are frequently in aluminium, die-cast or plastic housings, so the screw itself is harder than what it threads into — meaning you can round the recess long before the screw would actually shear.

The practical answer at this size is to seat the bit fully, drive at low torque, and prefer a hand driver where the fastener is small and the housing is soft.

Fifty millimetres is the power bit length, putting the tip clear of the chuck so it can reach into a recess rather than the chuck fouling on the surround — common on instrument and equipment work.

The steel is S2 industrial, hardened and tempered to HRC 58-62. S2 is a shock-resisting tool steel, which is what allows a bit to be that hard without shattering under a power driver. On a hex bit the hardness protects the six corners, which carry the entire load.

Satin finished, ten per plastic case.

The buyers are instrument and machinery fitters, electronics and equipment technicians, motorcycle and precision workshops, toolrooms, maintenance staff, and hardware dealers supplying workshops.

Seat the bit fully and drive gently. Ask us on WhatsApp for a price.