Cable routing. A conventional torch mounts externally with the cable dressed along the arm, which is cheaper and simpler to service but leaves a loop that can catch on fixtures and whose bend radius changes as the wrist turns, affecting wire feed. Through-arm torches route the cable inside a hollow wrist for consistent feeding and better access into confined fixtures.

Because a programmed collision happens at full speed with no reflex to stop it. The mount breaks away under load and signals the controller to halt, protecting the torch neck and, more importantly, the calibrated tool centre point that every taught position depends on. Without one, a minor crash turns into a bent torch, a lost TCP and re-verification of the program.

Three jobs between parts: it reams accumulated spatter out of the gas nozzle so shielding is not disrupted, sprays a measured dose of anti-spatter fluid to slow re-accumulation, and cuts the wire to a fixed stickout so the next arc start is consistent. It is triggered by the robot program on a set cycle.

The tool centre point is the position of the wire tip relative to the robot's wrist, and every taught position is expressed in relation to it. Change a torch, straighten a neck or suffer a collision and the real tip moves relative to the assumed one, offsetting every weld in the program. Calibration devices re-establish it, usually against a fixed reference pin or an optical sensor.

Generally yes. Duty cycles are far higher and there is nobody to notice degradation, so contact tips are specified for longer life and consistent bore, nozzles for spatter resistance and reliable seating in the cleaning station, and liners for stable feeding through a fixed cable path. Tip life directly sets how long a cell runs between interventions.

Water-cooled is the norm above moderate currents and on continuous duty, because the arc-on time that justifies the robot also generates heat a hand torch never accumulates. Air-cooled torches are lighter and simpler and suit lower current or intermittent work. Overrunning an air-cooled torch shows first as short consumable life.

From bulk drums or large spools rather than small reels, to keep run time between changes useful, fed through a conduit to a feeder mounted on or near the arm. Push-pull feeding and low-friction liners matter more than in manual work, because feed consistency directly affects arc stability on a machine that cannot compensate.