Set of Six Chucks with Intermediate Holder

Grooved waterproof case backs require a direct, matched interface to turn without riding out of the teeth. We machine this set of six ring chucks with milled teeth to seat into those perimeter flutes. The intermediate adapter takes the chucks and mounts them to the opener spindle.

Milled chuck teeth

We mill the teeth around the inner circumference of each ring to match the fluting on the case rim. The teeth seat into the recesses across the entire circle rather than touching on two points.

Graduated diameters

The rings come in sizes of 18.5 mm, 20.2 mm, 22.5 mm, 26.5 mm, 28.3 mm, and 29.5 mm diameter. You select the size that drops over the rim without binding on the outer case wall.

Intermediate holder adapter

The separate adapter block couples the individual chuck to your case opener spindle. It seats the ring flat so downward hand pressure translates evenly around the circumference of the back.

Fitting the chuck

Drop the ring over the case back by hand first to verify the teeth mesh cleanly with the grooves. Once seated, bring the holder down into engagement before applying torque.