Economical version of our popular 52 Series Industrial Caster. The swivel section features a cold forged top plate, yoke and button that are heat treated to prevent brinelling, improve swivel action and increase service life. Load and thrust bearings are hardened and ground and rotate on hardened raceways. All swivel sections are equipped with a lubrication fitting for field maintenance. RWM lubricates all swivel sections prior to shipment. Kingpin: 3/4" diameter bolt and locknut design. Rivet hydraulically compressed to increase strength of swivel section as compared to staking. Axle: 1/2" diameteer drilled axle with lubrication fitting provided on 2" casters to improve ease of lubrication. Zinc plated finish to protect against corrosion. Mounting plate size: 4.5" x 6.5" x 1/4". Bolt Hole Spaceing: 2-7/16" x 4-15/16", slotted to 3 3/8" x 5 1/4". Mounting Bolt Diameter: 1/2".