Mold your wheel and fork
- Tread shape and brake features match your cart
- You still buy bearings, axles, and swivels as hardware
- Load rating must be validated on your assembly tests
Molded part guide: casters
Injection Molded Caster Components
A catalog caster is an assembly of wheel, fork, axle, and swivel bearing. Custom programs often mold the wheel and fork in plastic while buying bearings and axles as hardware. NetProto molds the plastic pieces; final caster assembly stays with you.
Scope
Which caster parts belong in the mold
Medical carts, industrial dollies, and appliance stands use casters for mobility. The wheel tread may be hard PP or nylon, or a TPU overmold for floor grip and noise. The fork carries load from the plate to the axle and must not spread under impact.
Swivel casters add a vertical kingpin or ball race, usually metal, that plastic forks bolt around. Molded fork legs must clear the swivel hardware envelope and leave access for the axle clip.
Brake levers and foot pedals are often molded with the fork or wheel hub. Their flex and latch behavior resemble small latches and need the same fatigue review.
Parts
Typical molded caster components
| Component | Function | Design focus |
|---|---|---|
| Wheel | Rolls on floor or track | Tread roundness, bore fit, overmold bond |
| Fork | Supports axle and ties to mount plate | Leg stiffness, impact, metal insert for kingpin |
| Mount top plate | Bolts cart frame to caster | Mount hole pattern and warp on thin plate |
Sourcing
Custom molded caster parts versus catalog assembly
Buy finished casters
- Rated load and brake options come from the supplier catalog
- Less design freedom on fork height and lock style
- Fastest path when a standard size fits
Drawing
Caster component quote inputs
Which parts are molded versus purchased hardware
Wheel diameter, tread width, and floor type
Axle and bearing part numbers
Static and impact load cases
Brake and swivel envelope drawings
Chemical exposure on the plant floor or outdoors
Keep reading
Related guides
Rollers
Tread roundness and bore.
RollersOvermolding
Soft tread on hub.
OvermoldingTPU vs TPE
Tread material choice.
TPU vs TPEInsert molding
Kingpin metal in fork.
Insert moldingMounting brackets
Top plate bolt pattern.
Mounting bracketsLatches
Brake pedal snaps.
LatchesPolypropylene
Hard wheel cores.
PolypropyleneBushings
Plain bores in fork legs.
BushingsMolded parts hub
Every part-type guide.
Molded parts hubWheel hubs
Hub and bearing seat design for molded wheels.
Wheel hubsFAQ
Questions about molded caster parts
Do you sell complete casters?
NetProto quotes molded plastic parts from your CAD. Bearings, axles, and final caster assembly are outside molding scope.
Can you certify load rating like a caster catalog?
Load ratings on catalog casters come from the caster supplier tests. Your program validates molded parts in your cart assembly.
Can the wheel be two materials?
Yes with overmolding when the hub and tread resins bond. Send both materials and the tread bond area.
Our fork spreads after drop test.
Legs may need gussets, a stiffer resin, or a metal insert at the kingpin. Send the failed part and impact setup.
Next step
Quote the wheel, fork, or plate
Upload CAD for each molded component with hardware envelopes. DFM feedback covers tread roundness, fork stiffness, and inserts.