mining shovel

Improve maintenance time windows

Polygon EWS bearingEWS is a composite bearing for applications that require high load capacity and low frictional values. Capable of going extended periods without maintenance. Excellent for use in construction equipment, agriculture, and mining equipment when high contamination leads to premature wear and scheduled replacement.

mining truck tractor mining electric rope shovel

A leap forward in wear life

Polygon Company is proud to announce their newest PolyLube bearing line, the EWS bearing. In an industry where progress is typically around 10%–15%, EWS has shattered this expectation by showing a marked 300% improvement in a clean testing environment compared to PolyLube MRP’s industry-leading wear performance. Contaminated environments are also handled well, with an improvement of 350% versus MRP. This boost in performance is made possible through a significant technological leap in Polygon’s tribology research.

Product History

The inspiration for the EWS bearing was a high frequency, low oscillation angle agricultural application that built total sliding distances quickly and resulted in wear failures. To solve this, Polygon utilized tribology research to create a new composite bearing liner system, custom engineered to improve the performance of wear surfaces.

The EWS bearing has the same specifications as our flagship MRP bearing line but with increased wear resistance and reliability in contaminated joint locations with small design envelopes. Seals and their machining cost can sometimes be eliminated thanks to the increased contaminated environment performance.

ews wear graph

Mechanical & Physical Properties

Ultimate Compression Strength 70,000 PSI 483 MPa
Unit Load Limit 30,000 PSI 207 MPa
Temperature Range (Standard Formulation)* ±325°F -198 to 163°C
Coefficient of Thermal Expansion 4.8 x 10-6 in/in/°F 8.69 x 10-6 m/m/°C
Thermal Conductivity 1.8-2.3 (BTU*in(hr*ft2*°F)) .26 - .33 W/m*°K
Water Absorption (2 hours) 0.12%  0.12%
Water Absorption (24 hours) 0.16%  0.16%
Specific Gravity 1.87  1.87
Maximum Velocity 10 SFM 0.05 m/s

The PolyLube EWS bearing can withstand static loads of approximately 70,000 PSI and 30,000 PSI (483 MPa and 207 MPa) under dynamic loading. For dry running applications, the maximum speed is approximately 10 surface feet per minute (0.05 m/s). The typical average design pressure for high duty cycle applications is 10,000 PSI (69 MPa).

This bearing’s operating temperature range is ±325°F (-198 to 163°C). Maximum continuous operational surface temperature for the standard formulation is 325°F (163°C), depending upon load characteristics. The bearing has been heat stabilized at these temperatures, so that little dimensional change will occur in the bearing during operation. The thermal expansion coefficient of the PolyLube EWS bearing is approximately 4.8 x 10-6 in/in/°F (8.69 x 10-6 m/m/°C), close to steel and much lower than bronze alloys.

Product Benefits

Construction and mining equipment

bulldozerWhen large construction machinery is taken off-line, entire projects can be halted, leading to costly delays. The EWS bearing allows for equipment to operate maintenance-free for longer periods of time. Beyond the normal demands for reliability and predictability, this can also reduce the number of scheduled maintenance visits and their attendant downtime. Extended wear can allow scheduled bearing replacement to be combined with other major component overhaul maintenance schedules on a single call.

Learn more about Construction and Mining benefits.

Agricultural Equipment

corn row planterPlanting and harvesting seasons occur in narrow windows of time, requiring the equipment to be ready for use. The need for higher cycle bearings becomes increasingly important with today’s larger precision equipment. Not only does increased size bring more points of failure, machinery is moving through the fields faster as acres farmed per piece of equipment grows. EWS bearings are ideal for high cycle row crop opener locations.

EWS bearings show excellent wear properties in contaminated environments and can help move maintenance into off-season, preserving uptime in critical seasons.

Learn more about Agricultural benefits.

Note on Surface Finish

ews two tone side by sidePolygon uses two different OD finishing techniques which produce variations in color and texture. This color variation does not have an impact on performance.

All lab testing is done on finished bearings to assure specification conformance.

Compare bearings

High Cycle EWS

High Cycle EWS

300% more wear life for critical applications.

High Cycle EWS
All Purpose MRP

All Purpose MRP

MRP is our most versatile composite bearing.

All Purpose MRP
Improved RPM Glass Tape

Improved RPM Glass Tape

Glass Tape is low friction with slight load reduction.

Improved RPM Glass Tape
High Temp

High Temp

Sustains up to 475°F with low thermal distortion.

High Temperature
High Shock Load IFR

High Shock Load IFR

Tolerates higher shock and edge loading.

High Shock Load IFR
Guide Rod Bearings

Guide Rod Bearings

For guiding pneumatic and hydraulic pistons.

Guide Rod Bearings
Learn More – Machining

Learn More – Machining

Polygon has the capacity to produce complex bearing geometries.



Any ratings are typical for design purposes. Your design parameters may affect final ratings. Consult with a Polygon sales engineer for guidance. Final testing and approval is the customer's responsibility for their application. This information is derived from our testing and published data. There is no assurance of these properties, or warranty provided that these products are suitable for any particular purpose or operational situation.

Polygon certifies that their product will be free from material defect. Polygon will not accept any liability for loss, damages, or costs from use or misuse of our products.

Specifications are subject to change, and may be affected by our continual process of improvement. Changes may be made without prior announcement.