Heavy-Duty Step-Cut Piston Seal

Series 273: Heavy-Duty Step-Cut Piston Seal

The 273 Series Heavy-Duty Step-Cut Piston Seal is an ideal upgrade from traditional cast iron piston rings. Manufactured in a variety of high modulus materials, the 273 is easy to install and eliminates the threat of extrusion with higher-than-normal clearance gaps, as well as resists shearing when crossing ports. A single 273 seal can even replace multiple cast iron rings, while eliminating nuisance leaks. The 273 maintains the same wear-resistant characteristics as cast iron. Manufactured in a variety of materials and sizes from 6 mm to 2100 mm in standard or custom diameters.



Easy retrofit for cast iron piston rings

Can pass over ports

Eliminated leaks

Low friction

Will not extrude from large clearance gaps


Typical applications include:

  • Mobile Hydraulics
  • General Industry Hydraulics
  • Ideal for telescopic cylinders

System Seals has a number of custom blended compounds and high-performance materials suited for this product line. These materials include: UHMWPE, Polyamide, POM and glass reinforced polymers. Various energizer materials are available to suit the application, fluid and temperature.

Material Code
POM + NBR energizer ML03
Polyamide + NBR energizer ML06
Polyamide/Glass-Filled + NBR energizer ML51
PEEK + NBR energizer MK84
PEEK + FPM energizer MK85
Temperature ML03


hydraulic oil -30…+100 -22…+212 -30…+100 -22…+212
water oil emulsions (HFA) -…- -…- +5…+60 +40…+140
water-glycol fluids (HFC) -…- -….- -30…+60 -22…+140
polyol esters (HFD) - - - -
water -…- -…- -5…+100 +40…+212
Speed 5 m/s (16.5 ft/sec)
Pressure 400 bar (6000 psi)

Note: for other materials or fluids please contact our engineering department.