Parker's WPT profile tight-tolerance piston wear rings are the premier bearings for light- to heavy-duty hydraulic applications. In applications where pressure and temperatures reach their extremes, a tight tolerance wear ring (held to +/- .001” under 6”) allows for a more precise fit of components, resulting in less dimensional “play.” This allows the extrusion gap to be smaller for tight-tolerance wear rings, thus increasing the seal's pressure rating beyond what it is rated when used with standard-tolerance (+/-.0025) wear rings.

WPT Profile wear rings are available in standard sizes from 1" up to 12" bore diameters (larger sizes upon request). WPT profile wear rings feature chamfered corners on the I.D. and are designed to snap closed during assembly to hold tight against the piston, eliminating bore interference and simplifying installation.
Part numbers are shown for standard sizes and hardware dimensions and may be produced in virtually any width from 0.125 to 2.000 inch or larger based upon bore diameter. The “XXXX” characters in the part number reflect wear ring width based upon desired size.

For example: ½” wide = 0.500 and for part numbering purposes, final four XXXX characters would be substituted with 0500. (To produce final four characters of part number, use this method: 0.500 x 1000 = 0500.) For assistance with wear ring width calculations, please review literature in Product Support tab.

Three types of end cuts are available: butt cut (standard), angle cut, and step cut. The butt cut is the most common and most economical cut. Angle cuts and step cuts provide added performance by ensuring bearing area overlap at the wear ring's gap. For assistance with part numbering for angle cuts and step cuts, please view Section 9 of Parker's Fluid Power Seal Design Guide, Catalog EPS5370. (See link in the “Product Support” tab.)

Additional cross-sections may be available if required.

If you need technical assistance with determining recommended wear ring widths, or alternate cross-sections for your specific application, please contact Parker EPS Division's application engineering team at 801-972-3000.

Standard Material: W4733 WearGard™

Radial Tolerance:
• Up to 6” outside diameter: +.000"/-.002"
• 6” to 12” outside diameter: +.000/-.003”

End Cuts:
• Standard: Butt Cut
• Optional: Angle cut (skive cut), Step cut

Tight Tolerance Wear Ring for Pistons (WPT)