An economical version of our 46 series, these 45 series casters are designed to meet many of today"s wide array of caster application needs while maintaining a level of affordability that"s hard to beat. Among the most widely used sizes for casters, these casters work well in almost all industries. The 45 series medium duty casters are ideal for aircraft and aerospace, bakery carts, meat processing, assembly line and boat molding dollies, box trucks, conveyor stands, fixture carts, maintenance and material handling carts, mobile storage racks, mobile tool chests, shipping/receiving carts, tire racks, housekeeping carts, institutional equipment, janitorial equipment, laboratory equipment, electronic equipment and textile carts. 1/2" diameter axle. Mounting plate size is 4" x 4-1/2" x 1/4" and 2" tread wheel.