Williams 151SMW Micro-Adjustable Torque Screwdriver (3-15 in-lb)

Description

The Williams 151SMW is a micro-adjustable torque screwdriver for work that needs more than one torque value from the same tool — a positive-locking pull-down knob lets you dial in a new setting and read it against a window scale, rather than being fixed to a single preset like the single-setting line. Trilobular comfort grip; universal 1/4″ hex bit holder with a rare-earth magnet; cam-over clutch; auto-lock in the CCW direction to prevent accidental loosening while adjusting.

Range: 3-15 in-lb. Accuracy is ±6% of indicated value CW, from 20-100% of full scale, meeting or exceeding ASME B107.300 and ISO 6789. Individually serialized with a NIST-traceable certificate of calibration.

This is the right choice over a single-setting screwdriver when your work covers a range of fastener torques rather than one repeated value — bench assembly, prototyping, and multi-product lines are typical fits.

**Frequently asked questions**

**How does the cam-over clutch work?** At the set torque, the internal clutch “cams over” and slips rather than transmitting further torque to the fastener — this protects small screws from over-tightening and gives a consistent stopping point regardless of how hard the operator keeps pushing.

**Does it need periodic recalibration?** Yes — annually is typical, or per your quality system’s interval, since the internal clutch spring can drift with heavy use.

**What bits does it accept?** A universal 1/4″ hex bit holder with a rare-earth magnet accepts any standard 1/4″ hex driver bit.