Power Tools With Ball Bearings vs. Bushings

Ball Bearing Motors

• Motors built with ball bearings are much more durable for extended use than are motors built with bronze or steel bushings. The ball bearings do not build up friction and heat like bushing motors do. Consequently, ball bearing motors are designed into professional-grade tools, which are used more frequently than less-expensive homeowner-grade tools, and often under more demanding conditions.

Solid Bushing Motors

• Motors built with solid bushings are as reliable as better-engineered ball bearing motors, but they will not withstand the everyday use and abuse that the higher-quality tool encounters. In some tools, such as drills with lubricated gearboxes, the shafts in and out of the gearbox are mounted in bushings rather than bearings because heavy gear lubrication prevents friction from building up and creating wear on the bushings. Metal bushings are also used in power tools to protect areas that have sliding shafts. The bushings protect plastic tool housings from the heat and friction created by sliding shafts.

Durability

• Over the long run, a bearing motor is more durable than a motor built on solid bushings. As the motor's shaft spins, the bearings turn with the shaft, without vibration or friction. Shafts that spin in bushings eventually build up heat that can wear the bushings and damage tools.

Economy

• Entry-level power tools marketed to homeowners and first-time tool buyers usually have bushing motors and therefore cost less. Manufacturers pay much less for a single-piece extruded bronze bushing than for a multi-piece bearing. Bushings are also easier to install. The benefit of bushings is the cost savings to the manufacturer, which are passed along to the customer.