Polyurethane Rods

Nolathane polyurethane rods are solid lengths of engineering-grade polyurethane for making custom bushes, spacers, pads and isolators. When a ready-made part isn?t available, such as on a classic vehicle, a custom build, a race car or a piece of equipment, polyurethane rod gives fabricators and restorers the raw material to machine exactly what they need.

It?s the same type of material Nolathane has used in suspension bushings for decades, supplied in rod form so it can be cut, turned and drilled to suit almost any application.

What Polyurethane Rod Is Used For

Solid polyurethane rod, sometimes called polyurethane round bar or urethane rod, is used to make parts that need to be tough, resilient and resistant to wear. Common uses include:

• Custom suspension bushes for classic, rare or modified vehicles
• Spacers and packers that need to cushion as well as space
• Bump stop pads and travel limiters
• Body, cab and radiator mount isolators
• Steering and linkage bushes where no replacement exists
• Bushes for trailers, caravans and agricultural equipment
• Isolators and wear pads for machinery and workshop fixtures

Why Polyurethane

Polyurethane sits between rubber and hard plastics. It?s flexible enough to absorb vibration and shock, but firm enough to hold its shape under load. Compared with rubber, it offers:

• Outstanding abrasion resistance for parts that move or rub
• High load-bearing capability without deforming
• Increased tensile strength and tear resistance
• Resistance to oil, grease, ozone and weathering
• Good memory, returning to shape after being compressed

Nolathane has been making polyurethane suspension bushings since 1974, originally developed to replace brass bushes in hillclimb competition. That experience is why polyurethane is often the material of choice for custom bushes that need to last.

Rod, Sheet or a Ready-Made Part

Choosing the right starting point saves time and material. Polyurethane rod suits round, bored parts such as bushes, sleeves and cylindrical spacers. Polyurethane sheet suits flat parts such as pads, washers, isolators and gaskets. Where a vehicle-specific or universal ready-made bush exists in the correct size, it?s usually quicker and more consistent than machining a part from scratch.

Understanding Durometer

Polyurethane is made in different hardness grades, called durometers. Durometer is measured on the Shore A scale, where a lower number is softer and more flexible and a higher number is harder and more rigid.

• Softer grades absorb more vibration and shock and suit isolators and mounts where comfort matters
• Medium grades balance compliance and location and suit many suspension bushes
• Harder grades hold position more precisely and suit high-load or performance applications

Each listing shows the durometer and size of the rod, so you can choose the right grade for the job.

Machining Polyurethane Rod

Polyurethane can be machined with standard workshop equipment, but it behaves differently from metal or hard plastic. For the best results:

• Cutting: use a bandsaw or fine-toothed saw, cutting slowly to avoid heat build-up and melting
• Turning: use a lathe with very sharp, high-rake tools, light cuts and moderate speeds
• Drilling: use sharp drills at low speed, backing out often to clear swarf
• Cooling: use air or coolant to keep the material cool, as heat makes it gummy and hard to cut accurately
• Holding: grip the rod firmly without crushing it, as soft grades can deflect under clamping pressure

Polyurethane flexes slightly while being cut, so allow for small dimensional changes and check measurements once the part has cooled.

Designing a Custom Bush

A few principles help custom polyurethane bushes perform well:

• Leave enough wall thickness around the bore to support the load
• Use a steel inner sleeve or crush tube so the bolt can be tightened without crushing the bush
• Size the outer diameter for a snug fit in the housing without excessive interference
• Consider grease grooves on the bore of bushes that pivot
• Use flanged ends to locate the bush in its housing where needed
• Use a split, two-piece design where it makes fitting easier

Lubricate the moving surfaces of any custom polyurethane bush with a grease suitable for polyurethane.

Fitting Custom Polyurethane Parts

Once a custom bush or spacer is machined, fit it with the same care as a ready-made part:

1. Clean the housing and remove any burrs or rust that could cut the polyurethane.
2. Check the fit of the bush in its housing and the sleeve in the bush before final assembly.
3. Lubricate the bore, sleeve and flange faces with a grease suitable for polyurethane.
4. Press or push the bush into place evenly, without hammering directly on the polyurethane.
5. Tighten fasteners to specification, and tighten suspension pivots with the vehicle at ride height.

Inspect custom parts after the first few hundred kilometres or operating hours, checking for movement, extrusion or wear. Small adjustments to fit or durometer are common when developing a one-off part, so keep notes on dimensions and grades for future reference.

Limitations to Keep in Mind

Polyurethane is versatile, but it isn?t the right material for every job. It isn?t a structural material, so it shouldn?t replace metal parts that carry primary loads on their own. Very high temperatures, such as those close to exhaust components, can soften it. Harder grades transmit more vibration than rubber, so choose the durometer carefully for comfort-sensitive applications. For safety-critical suspension and steering positions, a purpose-designed, vehicle-specific part is always the first choice where one exists.

Who Polyurethane Rod Suits

• Classic and vintage vehicle restorers recreating bushes that are no longer made
• Custom and modified vehicle builders
• Motorsport teams and engineers making prototype or one-off parts
• Workshops that need to make a bush on the spot to finish a job
• Fabricators, engineers and DIY users working on trailers, equipment and machinery

Shop Polyurethane Rods

Need to make a custom bush? Nolathane rod stock sits in the universal parts range.

Choose the diameter and durometer to suit your project, then order online with fast shipping or pick up from a Nolathane reseller. 60-day returns give you time if a product isn?t right, and our local support team can help you choose a grade and size, whether you?re recreating a classic bush, building a custom suspension or making a one-off part in the workshop.