Atlas Copco LUM21 SR04-U Inline Pneumatic Screwdriver Air Shut-off Control

Atlas Copco LUM21 SR04-U Inline Pneumatic Screwdriver with Air Shut-off Control is a straight, inline model in Atlas Copco’s LUM line designed for precise torque control in compact assemblies. The SR04-U delivers 0.5–4.5 Nm (4.4–40 in-lb) of tightening torque and runs at up to about 320 rpm, suitable for light to medium fastening tasks. Weighing roughly 0.7 kg (1.5 lb) and about 240 mm long, it features lever-start shut-off control with a reverse ring for simple operation in-line setups. It uses a 1/8" air inlet, supports an 8 mm hose, and requires about 4 L/s of air at free speed; the model is cataloged under ordering number 8431 0277 22.