Max Knives MKRB910 — 10 mm ball bearing, nine balls, 5 mm bore

Overview

The MKRB910 is a ball bearing sold individually for rebuilding a folding knife or smoothing its action. It keeps the 10 mm outer diameter and 4 mm thickness of the MKRB6-10 but moves up to nine balls and a 5 mm bore, for a weight of 2 grams. It is the one to choose when the knife pivot measures 5 mm and the recess takes 10 mm.

What moving from six balls to nine changes

On a bearing, the number of balls decides how load is spread around the race. Six balls concentrate the contact on six points; nine spread it over nine closer points, which gives a more continuous rotation and better distributed contact around the same circumference. In the hand that reads as an opening that runs more evenly, without the stepped feel a bearing loaded on few points can produce. The MKRB910 does that in an identical footprint.

Technical specifications

Ball bearing, reference MKRB910, sold individually. Outer diameter 10 mm, inner diameter 5 mm, thickness 4 mm. Nine balls. Weight 2 grams. A workshop part for rebuilding a folding knife or smoothing its opening action. It keeps the 10 mm outer diameter of the MKRB6-10 while taking the ball count to nine and the bore to 5 mm.

Care

Nine balls mean nine more gaps for dust to settle into: rinsing the pivot deserves to be a regular habit on a knife that gets used often. Refit the bearing dry and clean, then give it a drop of fine oil that a few opening cycles will spread. On knives exposed to damp, drying fully before lubricating stops water from being trapped under the balls.