Decoding Caterpillar® Pistons: Casting Numbers vs. Part Numbers

IDENTIFICATION (casting) numbers vs PART numbers on other Caterpillar® pistons

Identification or casting numbers in the skirt or body of the piston may not represent the actual part number of the finished piston.

Manufacturers often assign an identification or casting number to an unfinished blank, or rough piston body. The benefit to the manufacturer is they can then machine these rough forms into several different finished piston part numbers.


  • A rough form OE piston with an identification #1073565 on the skirt is machined into a 1073565 (piston with one valve relief) or into a1654262 (piston with two valve reliefs)

Other examples of casting numbers that are also active part numbers are:

  • 7E7600 (3400 series)
  • 1073565 (3300 series)

Piston part numbers MUST be taken from the crown of the piston where the part number is usually stamped, etched, or inked, and NOT from the skirt or bottom of the piston body.

IPD Piston
IPD as always suggests that specific serial and arrangement numbers be provided to accurately identify what products belong in specific engines.