Delrin / Polyurethane / UHMW Bushings Buyers’ Guide
Polymer bushings — Delrin/POM, polyurethane and UHMW — are self-lubricating, compliant spacers and pivots for suspension arms, mounts and custom replacement work. This guide compares the three materials, explains the dimension system and how to specify from 35 standard sizes or to drawing.
What Are Polymer Bushings?
DefinitionPolymer bushings are machined plastic spacers and pivot sleeves used wherever a joint needs self-lubrication, vibration damping or corrosion-free operation — suspension arm bushings, cab mounts, control-arm pivots and countless custom replacement parts. Three materials cover the range: Delrin/POM for low-friction precision, polyurethane for compliant vibration damping, and UHMW for extreme wear life and impact toughness.
Because these bushings are usually replacements for specific OEM parts, SYZ supplies them in a B / D / D2 / W / T dimension system across 35 standard sizes — and machines custom bushings to your sample or drawing, which is how most specialty replacements are actually sourced.
- Also called
- Plastic bushings · acetal/Delrin spacers
- Core function
- Self-lubricating pivot, spacer, isolation
- Materials
- Delrin/POM · polyurethane · UHMW
- Sourcing
- 35 standard sizes + custom to sample
Anatomy: The Dimension System
StructureA bushing is fully described by five dimensions — that is the whole spec.
B (Bore)
The inner diameter that accepts the bolt, sleeve or shaft — the running clearance decision.
D & D2
The outer diameters: D seats into the housing bore; D2 (where present) is a step or flange diameter for locational mounts.
W (Width)
The bushing length that sets the installed stack width and the bearing surface area.
T (Thickness)
Wall or flange thickness where the design uses a stepped section — the material’s cross-section under load.
Delrin / POM
Acetal resin: low friction, high stiffness, excellent dimensional stability and moisture resistance. The default for smooth, precise pivots and replacement spacers.
The largest group in the catalog — from precision spacers to arm and cab-mount bushings.
Polyurethane & UHMW
Polyurethane adds compliant vibration damping — firmer and more durable than rubber, common for LCA and suspension-style mounts.
UHMW is the wear-and-impact champion: extremely slippery, nearly unbreakable, for high-wear sliding and impact pads.
What a Polymer Bushing Does in the Assembly
FunctionFour engineering jobs — the material you pick decides which job dominates.
Provide a self-lubricating pivot
Delrin and UHMW run dry against steel — no grease, no corrosion, no squeal. The pivot property that makes them suspension- and machinery-friendly.
Damp vibration
Polyurethane isolates and damps — the compliant middle ground between rigid metal and soft rubber.
Replace obsolete parts
The dominant real-world use: machining replacement bushings to a worn OEM sample or drawing in the polymer that outlasts the original.
Resist corrosion and chemicals
No plating, no rust — polymers survive washdown, salt and chemical exposure that destroys steel bushings.
Where polymer bushings fail in the field
- Material mismatched to load — polyurethane squeezed where Delrin stiffness was needed.
- Temperature limits ignored — polymers have ceilings steel doesn’t.
- Clearance copied from a steel bushing — polymers need their own running fit.
- UV exposure on non-UV-stabilized grades in outdoor service.
Compare the Three Materials
MaterialsEach material has a distinct personality — choose by the dominant requirement.
Delrin / POM
Low friction · stiffAcetal: low friction, high stiffness, dimensionally stable and moisture resistant. The precision pivot and replacement spacer material.
Polyurethane
Vibration dampingCompliant and tough — damps vibration like rubber but far more durable. The suspension-mount material (LCA bushings, cab mounts).
UHMW
Extreme wear lifeUltra-high-molecular-weight polyethylene: nearly frictionless, extremely impact-tough and wear-resistant — for high-wear sliding and pads.
Materials: Corrosion Is a Non-Issue
Surface treatmentPolymers need no plating or coating — corrosion resistance is inherent.
| Treatment | Applied to | Series examples | What it does |
|---|---|---|---|
| Delrin/POM, natural | Material color | Standard | No finish — the material is the finish; moisture and chemical resistant. |
| Polyurethane | Material color | Standard | Inherent resistance to oil, grease and many chemicals. |
| UHMW | Material color | Standard | Extremely low moisture absorption and chemical inertness. |
The full 35-size B/D/D2/W/T chart is on the polymer bushings spec page. Custom bushings are machined to sample or drawing.
Where Polymer Bushings Perform
ApplicationsAnywhere a pivot or spacer benefits from being plastic — and anywhere an obsolete part needs remaking.
Suspension Arm Bushings
Lower-arm and LCA-style replacements in polyurethane — durable, damped, corrosion-free.
PolyurethaneCab & Body Mounts
Vibration-isolating mounts for cab and body panels on work vehicles.
PolyurethaneUTV & Off-Road Parts
Model-specific replacement bushings (e.g., Maverick X3 class) in wear-resistant UHMW and PU.
UHMWPolyurethaneMachinery Spacers & Pivots
Delrin spacers and pivots in process equipment, packaging, fixtures and Washdown service. Confirm the polymer grade against the cleaning chemicals, temperature and operating conditions.
Delrin/POMMarine & Saltwater Equipment
Polymer bushings avoid the rusting associated with metal parts in marine mechanisms. Confirm the selected polymer grade against saltwater exposure, chemicals, load and temperature.
Delrin/POMUHMWPolyurethaneFood Equipment
Polymer bushings can serve pivots and spacers in food-processing equipment. Food-contact suitability is not implied; verify the exact material grade and applicable compliance requirements for the installation.
Grade-specificVerify complianceHow to Choose: 5 Steps, Then the Size Chart
Selection referenceIdentify the Job
Precision pivot → Delrin. Vibration damping → polyurethane. Extreme wear/impact → UHMW.
Set the Dimensions
Measure B, D, D2, W and T — or send the worn original as a sample.
Check the Environment
Temperature, UV, chemicals and load cycle — confirm the material’s limits.
Match the Running Fit
Polymers need different clearances than steel — rely on SYZ’s machined dimensions rather than copying a steel bushing.
Standard or Custom
Match a standard size if one fits; otherwise order custom machining to sample or drawing.
| Material | Character | Typical parts | Specs |
|---|---|---|---|
| Polymer bushing materials | |||
| Delrin / POM | Low friction, stiff, stable | Spacers, pivots, replacements | View |
| Polyurethane | Compliant, damped, tough | LCA/cab mounts, suspension | View |
| UHMW | Extreme wear, impact-tough | High-wear slides and pads | View |
Need the metallic counterpart? See forged poly bushings (steel body + PU insert) and rebuildable flex joints for structural flex pivots.
Get Selection HelpPolymer Bushing Buyers’ Questions
FAQQ1Delrin, polyurethane or UHMW — which material?
Q2Can you remake an obsolete bushing?
Q3What dimensions define a bushing?
Q4Do polymer bushings need lubrication?
Q5How many standard sizes are there?
Selecting Polymer Bushings?
Send us the dimensions — or the worn sample — and the working environment. SYZ engineers reply with the right material and factory-direct pricing, standards or custom.