Applications requiring higher load handling, speed or precision will need bearings with internal rolling elements. The type of bearing specified will vary according to the number of balls used, directly impacting the allowable load and speed.

The precision steel design  uses hardened-steel linear ball bearings that have point-to-point contact on a fixed point. This enables the handling of dynamic loads up to 5,000 lbf and diameters from 0.25 to 4 inches.

While all three linear bearings pictured use recirculating balls, their difference lies in that 2a employs a hardened sleeve that has a bearing surface ground into it, whereas 2b and 2c utilize floating bearing plates.

The next performance level up embeds a single ball track in a conforming groove on a floating plate (Fig. 2b). This bearing has a low coefficient of friction and can triple the load handling capability over the fixed plate — increasing bearing life up to 27 times longer than precision bearings. This configuration is optimal for rail 0.19 to 2 inches in diameter and dynamic loads up to 3,000 lbf.

The more load-bearing balls in the load zone, the greater the load handling and durability. Deploying two ball tracks in a conforming floating track, for example, can increase the load capacity six times and bearing life 216 times over the precision bearing. This configuration is also optimal for rail 0.5 to 1.5 inches in diameter and dynamic loads up to 3,880 lbf.