Pick the right 3-1/4" x 2" in four questions
1. What's the floor?→ Smooth indoor concrete: polyurethane on iron. Oily or solvent areas: phenolic. Finished/quiet floors: mold-on rubber.
2. How heavy per caster?→ Under 350 lb: polyurethane on polyolefin core. 350-900 lb: polyurethane or phenolic on iron core.
3. Plate mount or stem?→ Plate for new builds and inspected equipment. Stem for retrofits into existing sockets.
4. Does it sit static under load?→ Yes: avoid soft rubber (flat-spots). Pick phenolic or polyurethane on a metal core.
Why this size exists
The 3-1/4" diameter is unusual — most catalogs jump from 3" to 4". B&P, Hamilton, and several OEM equipment lines spec 3-1/4" x 2" specifically because it drops into existing 3-1/4" sockets and mounting patterns on legacy equipment. If you're replacing casters on an older machine and the diameter measures 3-1/4", this is the size — a 3" or 4" won't seat the same.
Common questions
Is 3-1/4" interchangeable with 3" or 4"?No — the mounting height and often the socket differ. Measure your existing wheel diameter exactly before ordering.
What capacity does the 2" tread give?Up to ~900 lb per caster on a metal core. The 2-inch width is what separates this from a furniture caster of similar diameter.
Phenolic or polyurethane?Phenolic for oil/solvent resistance and low rolling resistance. Polyurethane for floor protection and quieter roll.
Matching a legacy socket?
Measure your old wheel and mount. We'll confirm the 3-1/4" x 2" fit.
Call 844-439-4335
