Williams Comfort Products 401SMW Torque Screwdriver 5-40 in Lb

Product Description

The WILLIAMS COMFORT PRODUCTS 401SMW is a micro-adjustable torque screwdriver designed for precision fastening applications where controlled torque output is critical. Rated from 5 to 40 inch-pounds, it uses a cam-over torque limiting clutch that disengages automatically at the set value, delivering consistent repeatability and accuracy within plus or minus 6 percent of indicated value in the clockwise direction across 20 to 100 percent of full scale. The tool accepts standard 1/4 inch hex bit holders and is held securely by a built-in rare earth magnet. It is individually serialized and ships with a certificate of calibration traceable to N.I.S.T. HVAC technicians, electricians, and mechanical service professionals rely on tools like this for terminal block fastening, control board mounting, and other low-torque precision work.

The 401SMW suits applications where overtightening small fasteners risks stripping threads or damaging sensitive components. Common use cases include securing electrical panel components, HVAC control board hardware, and small mechanical assemblies in both residential and commercial service environments. The automatic lock in the counterclockwise direction also allows controlled screw removal without switching tools. The trilobular comfort grip reduces hand fatigue during repetitive fastening tasks, making it practical for high-volume service calls.

Key Features

• Cam-over torque limiting clutch for automatic disengagement at the set torque value
• Micro-adjustable range of 5 to 40 inch-pounds with positive locking pull-down adjustment knob
• Accuracy within plus or minus 6 percent of indicated value, clockwise, from 20 to 100 percent of full scale
• Universal 1/4 inch hex bit holder with strong rare earth magnet
• Automatic lock in the counterclockwise direction for screw removal
• Individually serialized with N.I.S.T.-traceable certificate of calibration
• Meets or exceeds ASME B107.300-2010 and ISO 6789 standards

Compatibility

Designed for use with standard 1/4 inch hex shank screwdriver bits; compatible across a broad range of precision fastening tasks in HVAC, electrical, and mechanical service applications.

Installation Notes

This tool is intended for use by trained trade professionals performing precision torque-sensitive fastening. Before servicing any electrical or HVAC equipment, de-energize the system and follow applicable lockout/tagout procedures per NFPA 70E and local code requirements. Set the desired torque value using the adjustment knob before applying the tool to fasteners, and confirm the lock is engaged to prevent unintentional adjustment during use.

Technical Specifications

• Torque Range: 5-40 inch-pounds
• Drive Size: 1/4 inch hex
• Torque Accuracy: plus or minus 6 percent of indicated value, CW, 20-100 percent of full scale
• Weight: 0.85 pounds
• Standards: ASME B107.300-2010, ISO 6789
• Calibration: N.I.S.T.-traceable certificate included
• Unit of Measure: Each

Standard Information

• Brand: WILLIAMS COMFORT PRODUCTS
• Manufacturer Part Number: 401SMW