HAAS^® Alarm 175 — CHUCK NOT CLAMPED

What it means

The lathe was about to start a cut but the chuck clamp signal isn't confirming that the workpiece is held. Cutting an unclamped part is a serious safety risk.

Common causes

• Hydraulic pressure low (most lathe chucks are hydraulic)
• Chuck clamp foot pedal or button not properly engaged
• Clamp confirmation switch faulty
• Part too small for the jaw range — jaws bottoming before gripping

What to check first

• Confirm the part is actually gripped — try to move it by hand
• Check hydraulic pressure
• Inspect the clamp confirmation switch
• Never override this alarm without understanding why it triggered

Prevention

Tool-changer faults are almost always either air pressure or chip contamination. Keep shop air at 85–100 psi clean and dry, and clear chips and coolant residue from the changer area weekly. On lathes, check turret lubrication monthly. If you have an intermittent fault that disappears when you reset, don't ignore it — book it in before it becomes a hard fail.

If you’re still stuck

If you’ve worked through the checks above and the alarm hasn’t cleared — or if it cleared and came back — that’s the point to call. Persistent alarms after a reset usually mean a real component fault, and pushing through them risks turning a simple repair into a bigger one. Keith covers HAAS^® breakdowns across the UK with same-day phone diagnosis.