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Style PSC Bronze Filled Piston Seal, 4.00 Inch Bore Diameter, 3.38 Inch Groove Diameter, Inch Groove Width

Bore 4	Bore Tolerance (in) +0.004/-0	Brand Hercules Sealing Products	Brand Hercules Sealing Products	Pack Size 1.00	UOM EA	Groove Dia. E 3.38	Groove Width Tolerance (in) +0.005 / -0	Piston Dia. F 4.00	Seal Height B 0.27	Supplier Part Number PSQ-64	Alternate Part Numbers Alternate Part Number C1GN15, Alternate Part Number MI-03110293, Alternate Part Number MINO-00407X12258	Product Weight 0.07 lbs

Product Questions & Answers 3

Product Questions & Answers

got a 4 inch bore cylinder, is this PSC seal the right size or am i gonna be fighting it

Question by: Kent W on Jan 30, 2026, 6:27 PM

The key callouts are a 4.00 inch bore and a piston diameter (F) of 3.999 inches, with the note that those piston dimensions are for pistons without wear rings. It’s also built around a groove diameter of 3.384 inches, and the bore tolerance listed is +0.004 / -0.

Answer by: Customer Support on Feb 1, 2026, 6:01 PM

What’s the deal with needing no wear rings for this thing to work right?

Question by: Kurt W on May 26, 2025, 3:51 PM

This piston seal is sized specifically for pistons that don't have wear rings, so it fits properly and seals as it should.

Answer by: Customer Support on May 28, 2025, 6:18 AM

Got a 4-inch bore cylinder that don't have wear rings on the piston, will this seal work for that setup?

Question by: Rod W on Sep 23, 2025, 9:30 AM

That's what this seal is built for. The piston diameter spec listed is 3.999 inches, and the groove diameter comes in at 3.384 inches, so it fits right into that bore without needing wear rings to function properly. The 40% bronze-filled PTFE construction helps it handle the side loading and friction that pistons without wear rings tend to see more of.

Answer by: Customer Support on Sep 25, 2025, 6:39 AM

Similar Products

Model Number	Bore	Seal Height B	Groove Dia. E	Piston Dia. F	Bore Tolerance (in)	Groove Width Tolerance (in)
PSQ-40	2.5	0.271	1.884	2.499	+0.004/-0	+0.005 / -0
PSQ-48	3	0.271	2.384	2.999	+0.004/-0	+0.005 / -0
PSQ-56	3.5	0.271	2.884	3.499	+0.004/-0	+0.005 / -0
PSQ-64	4	0.271	3.384	3.999	+0.004/-0	+0.005 / -0
PSQ-80	5	0.271	4.384	4.999	+0.004/-0	+0.005 / -0