Small fasteners are where cheap bits die — rounding a 4 mm socket head inside a device is a special kind of bad day.
Wiha's 75623 MicroBits are the fix: precision-machined, exact-fit 4.0 mm metric hex tips in Wiha's System 4 micro bit format, made in Germany from high-performance CRM72 modified tool steel and through-hardened for long-term edge retention on the particularly small screws found in electronics, optics, instruments, and fine mechanics.
Know the format before you buy: System 4 means a 4 mm micro drive, not the standard 1/4" hex.
These 28 mm (1.1") bits fit Wiha's 4 mm MicroBit handles, torque drivers, and micro bit holders — the precision ecosystem built for exactly this scale of work — or drop into a standard 1/4" driver via Wiha's 75802 MicroBit adapter. The small drive keeps the tool head compact and the tip concentric, which is the whole point at this fastener size.
The exact-fit machining is what you're paying Wiha for.
Full-depth seating, no cam-out, no chewed sockets — and the 10-pack keeps a fresh edge in the driver and spares in the case at a per-bit price that makes retiring a worn bit an easy call.
Features:
- Precision-machined exact-fit 4.0 mm metric hex tips
- Wiha System 4 MicroBit format: 4 mm micro drive, 28 mm length
- High-performance CRM72 modified tool steel, through hardened
- Ideal for electronics, optical, and precision tooling work
- Fits Wiha 4 mm MicroBit handles and holders (or 1/4" drivers via Wiha 75802 adapter)
- 10 bits per pack; made in Germany
Specifications:
- Model: Wiha 75623 (System 4 MicroBit)
- Tip: 4.0 mm hex, metric
- Drive: 4 mm micro (System 4)
- Length: 28 mm (~1.1")
- Material: CRM72 modified tool steel, through hardened
- Quantity: 10
- Origin: Made in Germany
- UPC: 084705756233