Ball, Steel, 5 mm

Exactly 5 mm, so it dropped right into the detent hole on my lathe without any filing needed. The steel feels dense and well-made, definitely not a cheap ball bearing.

Tiny part, big job—this ball dropped straight into the detent on my lathe and the spindle locked solid again. The 5 mm diameter measured spot-on with calipers, and it’s been holding tension without a hint of wear.

Exactly 5.00 mm when I checked with my calipers, so it seated perfectly in the detent on my lathe. It’s a small thing, but having a precise replacement part that just works is a relief.