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Style PSC Polyurethane Double-Acting Piston Seal, 3.50 Inch Bore Diameter, 3.13 Inch Groove Diameter, Inch Groove Width

Description & Features

Designed for double-acting piston applications, the Style PSC Polyurethane Double-Acting Piston Seal handles cylinder bore diameters of 3.50 inches with a groove diameter of 3.125 inches and a piston diameter of 3.498 inches. The two-piece construction pairs a 95A polyurethane sealing element with a 70A nitrile energizer, delivering consistent radial load and reliable sealing performance across a wide range of service conditions.

Rated for pressures from 0 to 5,000 PSI and temperatures spanning -65°F to 220°F, this seal is well-suited for hydraulic cylinders operating in demanding industrial environments. Bore tolerance is held to +0.004/-0 inches, and piston diameter tolerance to +0/-0.004 inches, supporting precise fitment. Piston diameter dimensions are referenced for pistons without wear rings. Manufactured by Hercules Sealing Products.

SKU: PSC-338

Supplier Part Number (MPN): PSC-338

Alternate Part Numbers: C1GG36, MI-01037556, MINO-00407X30168

Specifications

Bore 3.50	Bore Tolerance (in) +0.004/-0	Brand Hercules Sealing Products	Brand Hercules Sealing Products	Pack Size 1.00	UOM EA	Groove Dia. E 3.13	Groove Width Tolerance (in) +0.005 / -0	Piston Dia. F 3.50	Piston Dia. Tolerance (in) +0/-0.004	Seal Height B 0.26	Supplier Part Number PSC-338	Alternate Part Numbers Alternate Part Number C1GG36, Alternate Part Number MI-01037556, Alternate Part Number MINO-00407X30168	Product Weight 0.02 lbs

Similar Products

Model Number	Bore	Seal Height B	Groove Dia. E	Piston Dia. F	Bore Tolerance (in)	Groove Width Tolerance (in)	Piston Dia. Tolerance (in)
PSC-218 Double-Acting Piston Seal	1.5	0.15	1.254	1.498	+0.002/-0	+0.005 / -0	+0/-0.002
PSC-218-WB Double-Acting Piston Seal	1.5	0.265	1.254	1.498	+0.002/-0	+0.005 / -0	+0/-0.002
PSC-326 Double-Acting Piston Seal	2	0.255	1.625	1.998	+0.002/-0	+0.005 / -0	+0/-0.002
PSC-326-WB Double-Acting Piston Seal	2	0.37	1.625	1.998	+0.002/-0	+0.005 / -0	+0/-0.002
PSC-330 Double-Acting Piston Seal	2.5	0.255	2.125	2.498	+0.002/-0	+0.005 / -0	+0/-0.002
PSC-334 Double-Acting Piston Seal	3	0.255	2.624	2.997	+0.002/-0	+0.005 / -0	+0/-0.004
PSC-334-WB Double-Acting Piston Seal	3	0.37	2.624	2.997	+0.004/-0	+0.005 / -0	+0/-0.004
PSC-338 Double-Acting Piston Seal	3.5	0.255	3.125	3.498	+0.004/-0	+0.005 / -0	+0/-0.004
PSC-342 Double-Acting Piston Seal	4	0.255	3.625	3.998	+0.004/-0	+0.005 / -0	+0/-0.004
PSC-342-WB Double-Acting Piston Seal	4	0.37	3.625	3.998	+0.004/-0	+0.005 / -0	+0/-0.004
PSC-350 Double-Acting Piston Seal	5	0.255	4.636	4.999	+0.004/-0	+0.005 / -0	+0/-0.004
PSC-433-WB Double-Acting Piston Seal	6	0.5	5.521	5.999	+0.004/-0	+0.006 / -0	+0/-0.004

Product Questions & Answers (3)

Question by: Hubert S on Sep 18, 2025, 8:30 AM

got a 3.50 inch bore cylinder that needs a new piston seal, does this two-piece setup work for double-acting applications or just single direction?

Answer by: Customer Support on Sep 20, 2025, 8:13 AM

Double-acting is exactly what the PSC style is built for. The seal pairs a 95A polyurethane sealing element with a 70A nitrile energizer, and that combination handles pressure in both directions of stroke. Bore diameter on this one is 3.50 inches, groove diameter is 3.125 inches, and the piston diameter it's sized for is 3.498 inches. Bore tolerance runs +0.004/-0 and piston diameter tolerance is +0/-0.004, so as long as your cylinder is machined to those specs, fitment should be solid.

Question by: Tommy A on Aug 7, 2025, 6:44 PM

What size groove is this seal made for?

Answer by: Customer Support on Aug 9, 2025, 6:16 AM

It's designed for a groove diameter of 3.125 inches.

Question by: Pete S on Oct 27, 2025, 7:01 PM

got a 3.50 bore cylinder, will this PSC-338 seal fit the piston and groove sizes or am i gonna be fighting it

Answer by: Customer Support on Oct 29, 2025, 6:30 PM

The key dimensions on this seal are a 3.50 inch bore, a 3.125 inch groove diameter, and a 3.498 inch piston diameter. The tolerances called out are bore +0.004/-0 and piston +0/-0.004, with groove width tolerance +0.005/-0. Also note the piston diameter dimension is referenced for pistons without wear rings.