Rubber key for opening and closing cases of waterproof watches Watchmaker

A soft rubber head catches the flat metal of a screw back by friction alone. We turn this key to run threads home or to spin a loosened case back off the case ring. It suits clean threads and backs that are already broken free of their initial torque.

Rubber friction face

The 23mm contact face relies on grip across the flat steel rather than pins in milled notches. You press downward into the center of the case back while turning the body.

Thread engagement

Use this tool to catch the first turn of a thread squarely before final torque. It spins freely once the heavy resistance of the gasket is overcome.

Body and grip

The turned handle sits upright in the palm. It provides enough purchase for direct hand pressure while keeping metal jaws away from the case rim.

Bench maintenance

Keep the rubber face dry and clear of bench grease or oil. Wiping the contact surface across clean tissue restores the grip when dust settles on it.