If the existing wheel has a keyway slot in the bore
Spec the polyurethane KEYED variant — this is the tow-line / drive-wheel configuration used on motorized carts and AGV platforms. The keyway transfers torque from the drive motor through the bore to the wheel hub.
If the existing wheel has a smooth bore (no keyway)
Spec the polyurethane, polyolefin, or phenolic standard bore variant. Match bore diameter (5/8″ or 3/4″) to the existing axle. Capacity 450-700 lb per wheel.
If you need solid polyurethane (no metal hub)
Spec the solid polyurethane variant — 700 lb capacity, chemical-resistant, no bonding-adhesive failure mode. For chemical or food-grade applications where the metal hub of standard poly-on-iron is a concern.
If you’re replacing the entire caster (not just the wheel)
5″ x 1-1/2″ complete caster assemblies are limited — most applications at this size are wheel-only. For full caster replacement, step up to 5″ x 2″ casters (1,000+ lb capacity) which use the same 4″ x 4-1/2″ plate.
Why is the 5″ x 1-1/2″ mostly wheel-only?
This is a niche size that exists primarily on factory-built equipment from a few manufacturers (Hamilton, Faultless, Caster Concepts). Buyers in this size class are typically replacing a worn wheel on an existing caster yoke — the yoke is tight, the bearing is fine, only the rubber/polymer tread has worn through. Wheel-only replacement costs about 35-45% of a full caster.
What does “keyed” mean on a wheel bore?
The wheel bore has a longitudinal slot cut along its length that mates with a matching key (rectangular bar) on the axle. The keyway transfers rotational torque from the axle to the wheel — required for tow-line drive wheels on AGV platforms and motorized cart applications where the wheel must spin under power. Standard non-keyed wheels are press-fit and rotate freely on the axle.
What bore sizes are common at 5″ x 1-1/2″?
5/8″ and 3/4″ are the two dominant bores. Hamilton typically uses 1/2″ or 5/8″ on caster yokes; Faultless and Caster Concepts use 5/8″ and 3/4″. Measure the existing axle diameter before ordering. If you have the existing wheel, measure the bore directly.
Can I use a 5″ x 1-1/4″ wheel in a 5″ x 1-1/2″ yoke?
Not cleanly. The 1/4″ tread-width difference means the 1-1/4″ wheel rattles in a 1-1/2″ yoke, the bearing wears prematurely from lateral slop, and the swivel feels loose. Match wheel width to yoke width.
How fast does this ship?
Stock 5″ x 1-1/2″ wheels ship same day from Mansfield, TX before 3 pm Central. Specialty keyed-bore variants may have 1-2 day production lead time depending on key dimension — standard 1/4″ x 1/8″ keyway ships from stock, custom keyways drop-ship from the manufacturer.
