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Style PSC Polyurethane Double-Acting Piston Seal, 1.50 Inch Bore Diameter, 1.25 Inch Groove Diameter, Inch Groove Width

Bore 1.50	Bore Tolerance (in) +0.002/-0	Brand Hercules Sealing Products	Brand Hercules Sealing Products	Pack Size 1.00	UOM EA	Groove Dia. E 1.25	Groove Width Tolerance (in) +0.005 / -0	Piston Dia. F 1.50	Piston Dia. Tolerance (in) +0/-0.002	Seal Height B 0.15	Supplier Part Number PSC-218	Alternate Part Numbers Alternate Part Number C1KM95	Product Weight 0.01 lbs

Product Questions & Answers 5

Product Questions & Answers

got a 1.50 bore cylinder, is this PSC-218 the right size seal or am i gonna be fighting it

Question by: Ricky T on Jan 4, 2026, 8:14 PM

The key numbers are a 1.50 inch bore with a +0.002/-0 tolerance, and a piston diameter of 1.498 inch with a +0/-0.002 tolerance. The seal is sized around a 1.254 inch groove diameter, and it has a 0.15 inch seal height, so it is meant to run in that groove setup rather than being a universal “close enough” seal.

Answer by: Customer Support on Jan 6, 2026, 3:53 PM

what's the pressure range on this seal? got a cylinder running around 3,500 PSI and need to know if it'll hold up

Question by: Ray M on Sep 12, 2025, 4:57 PM

Rated from 0 to 5,000 PSI, so 3,500 falls well within its operating range. The 95A polyurethane construction handles pressure pretty well without deforming under load, and the 70A nitrile energizer helps keep consistent contact against the bore wall throughout the pressure cycle.

Answer by: Customer Support on Sep 13, 2025, 5:25 PM

What size groove does this seal fit into? Just wanna make sure it matches up with my cylinder.

Question by: Shane S on Feb 23, 2026, 2:47 PM

The groove diameter it needs is 1.254 inches, with a groove width tolerance of +0.005 / -0 inches.

Answer by: Customer Support on Feb 24, 2026, 7:04 PM

Got a 1.5 inch bore cylinder that needs a new piston seal. Will the PSC-218 drop right in, or is there more to it than that?

Question by: Harold H on Apr 9, 2025, 4:25 PM

For a 1.50 inch bore, this seal is built to fit a piston diameter of 1.498 inches, with a tolerance of +0 / -0.002. The groove it seats into should be 1.254 inches in diameter. One thing worth knowing is that those piston diameter dimensions are given for pistons running without wear rings, so if your setup uses wear rings, that changes the fit calculation. Get those groove and piston dimensions confirmed before ordering and you should be in good shape.

Answer by: Customer Support on Apr 10, 2025, 7:54 PM

I need to know if this piston seal will fit my cylinder without wear rings. What piston diameter should I be looking for?

Question by: Bonnie M on Sep 2, 2025, 2:51 PM

For pistons without wear rings, you'll want a piston diameter of 1.498 inches. The acceptable tolerance is +0/-0.002 inches.

Answer by: Customer Support on Sep 4, 2025, 1:14 PM

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	1.5	0.15	1.254	1.498	+0.002/-0	+0.005 / -0	+0/-0.002
PSC-218-WB	1.5	0.265	1.254	1.498	+0.002/-0	+0.005 / -0	+0/-0.002
PSC-326	2	0.255	1.625	1.998	+0.002/-0	+0.005 / -0	+0/-0.002
PSC-326-WB	2	0.37	1.625	1.998	+0.002/-0	+0.005 / -0	+0/-0.002
PSC-330	2.5	0.255	2.125	2.498	+0.002/-0	+0.005 / -0	+0/-0.002
PSC-334	3	0.255	2.624	2.997	+0.002/-0	+0.005 / -0	+0/-0.004
PSC-334-WB	3	0.37	2.624	2.997	+0.004/-0	+0.005 / -0	+0/-0.004
PSC-338	3.5	0.255	3.125	3.498	+0.004/-0	+0.005 / -0	+0/-0.004
PSC-342	4	0.255	3.625	3.998	+0.004/-0	+0.005 / -0	+0/-0.004
PSC-342-WB	4	0.37	3.625	3.998	+0.004/-0	+0.005 / -0	+0/-0.004
PSC-350	5	0.255	4.636	4.999	+0.004/-0	+0.005 / -0	+0/-0.004
PSC-433-WB	6	0.5	5.521	5.999	+0.004/-0	+0.006 / -0	+0/-0.004