If your application is HIGH-TEMPERATURE (this page is right)
Oven rack carts, paint booth carts, bakery production, foundry-adjacent transport. Z20P epoxy resin (500 lb @ 475°F continuous), glass-filled nylon (350 lb @ 475°F, autoclave-safe), high-temp swivel (300 lb @ 475°F). Same wheel size as the broader 4″ class but engineered for heat.
See also: Bakery & High-Temp Hub and Bakery Oven Rack spec.
If your application is STANDARD light-medium duty (NOT heat)
Service carts, prep tables, light shop trucks, retail fixtures. The 4″ x 1-1/4″ size class (550 products, 200-500 lb capacity, 5 tread materials) is the dominant non-heat spec at this wheel diameter.
Go to 4″ x 1-1/4″ Casters & Wheels for the full standard catalog.
Why does this collection skew high-temp?
The 4″ x 1-1/2″ wheel size matches the specific dimensional spec on commercial bakery rack ovens (Baxter, Hobart, BKI). Manufacturers chose this size for the wheel-to-floor clearance + capacity combination at oven rack mounting heights. Standard light-medium duty applications converged on the slightly narrower 4″ x 1-1/4″ spec instead — cheaper to manufacture, sufficient capacity for non-heat use.
Will 4″ x 1-1/4″ fit a 4″ x 1-1/2″ mount?
The plate dimensions sometimes match, but the wheel itself is narrower in the yoke — the 1-1/4″ wheel rattles in a 1-1/2″ yoke and the bearing wears prematurely. If you’re changing tread width, replace the entire caster — not just the wheel.
Z20P vs glass-filled nylon — which one?
Z20P epoxy resin for DRY heat applications (paint booth, dry-cycle bakery) at 500 lb capacity. Glass-filled nylon for moist-heat / steam-cycle applications (autoclaves, proofers, smokehouse) at 350 lb capacity. Both rated 475°F continuous, 530-550°F intermittent.
How fast does this ship?
Stock high-temp 4″ x 1-1/2″ casters ship same day from Mansfield, TX before 3 pm Central. Standard configurations ship UPS Ground. Specialty Z20P and GFN bakery rack casters may have 1-2 day production lead time depending on order quantity.
