What are H4 screwdriver bits?

H4 screwdriver bits are precision bits with a 4 mm hexagonal shank, commonly used in compact screwdriver handles and electronics repair sets.

The main characteristics are:

4 mm hex shank: smaller than standard 6.35 mm / 1/4-inch bits

Designed for precision work: suitable for phones, laptops, cameras, watches, game consoles, and other electronics

Slim profile: easier to reach screws inside narrow or recessed areas

Wide tip selection: available in Phillips, Slotted, Torx, Security Torx, Pentalobe, Tri-point, Hex, and other specialty profiles

Different lengths: common H4 bit lengths include approximately 28 mm, 39 mm, and 45 mm

Compatible with precision handles: often used with magnetic bit holders and slim aluminum screwdriver handles

Compared with H6.35 / 1/4-inch bits, H4 bits are smaller and better suited for delicate, low-torque repair work. H6.35 bits are generally better for higher-torque household, mechanical, and ratchet applications.

For professional precision screwdriver sets, buyers should also check the bit material, hardness, tip accuracy, and length, not only the 4 mm shank size.

ToolQeen precision screwdriver sets commonly use H4 bits in multiple lengths, with S2 and CR-V material options and customizable bit combinations for OEM and wholesale projects.