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Cast Iron Piston Ring, 7.00 Inch OD, 0.249 Inch Width, 0.24 Inch Wall Thickness

Description & Features

This Hercules Sealing Products cast iron piston ring is suitable for use in hydraulic cylinders and other reciprocating mechanisms. The 7.00-inch outside diameter ring has a width of 0.249 inches and a wall thickness of 0.24 inches.

When installing, ensure grooves are at least 0.015 inches deeper than the maximum radial wall thickness to prevent bottoming. The groove should also be at least 0.001 inches wider than the maximum piston ring width for free movement. The radial clearance between the cylinder bore and piston should be less than 1/3 of the radial wall thickness to ensure sealing effectiveness.

SKU: SPR-7002

Supplier Part Number (MPN): SPR-7002

Alternate Part Numbers: C1GG42

Specifications

Brand Hercules Sealing Products	Brand Hercules Sealing Products	Pack Size 1.00	UOM EA	O.D. 7 in	Supplier Part Number SPR-7002	Wall Thickness 0.24	Product Weight 0.32 lbs	Alternate Part Numbers Alternate Part Number C1GG42

Similar Products

Model Number	O.D.	Width (in)	Wall Thickness
SPR-4002 Cast Iron Piston Ring	4 in	0.187	0.135
SPR-6004 Cast Iron Piston Ring	6 in	0.311	0.199
SPR-7002 Cast Iron Piston Ring	7 in	0.249	0.236

Product Questions & Answers (2)

Question by: Danny H on Feb 8, 2026, 11:30 AM

got a hydraulic cylinder here with a 7-inch bore and the piston ring groove needs to be cut right, what clearances am I working with on the groove depth and width for this ring?

Answer by: Customer Support on Feb 10, 2026, 7:58 AM

Groove depth needs to be at least 0.015 inches deeper than the maximum radial wall thickness of the ring, with a tolerance of plus 0.003, minus nothing. That extra depth keeps the ring from bottoming out in the groove once it gets compressed down to working diameter. On the width side, cut the groove at least 0.001 inches wider than the maximum ring width, same tolerance of plus 0.003, minus nothing. That gives the ring enough room to slide freely without binding up during operation.

Question by: Bobby B on Apr 5, 2026, 4:43 PM

got a piston cut for a 7 inch ring, is this one actually 7.00 OD and about a quarter inch wide?

Answer by: Customer Support on Apr 7, 2026, 9:32 AM

The key dimensions on this ring are a 7.00 inch outside diameter and a 0.249 inch width. It is a cast iron piston ring, sold under SKU SPR-7002, with alternate part number C1GG42.