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Cast Iron Piston Ring, 4.00 Inch OD, 0.187 Inch Width, 0.14 Inch Wall Thickness

Description & Features

This cast iron piston ring from Hercules Sealing Products features a 4.00 inch outside diameter.

It has a width of 0.187 inches and a wall thickness of 0.14 inches, suitable for applications where precise sealing is required.

SKU: SPR-4002

Supplier Part Number (MPN): SPR-4002

Alternate Part Numbers: C1DK99

Specifications

Brand Hercules Sealing Products	Brand Hercules Sealing Products	Pack Size 1.00	UOM EA	O.D. 4 in	Supplier Part Number SPR-4002	Wall Thickness 0.14	Product Weight 0.08 lbs	Alternate Part Numbers Alternate Part Number C1DK99

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 (3)

Question by: Shawn M on Jul 13, 2025, 9:59 PM

So, this here ring... it's cast iron, right? Just wanna make sure it'll hold up for what I need it for.

Answer by: Customer Support on Jul 15, 2025, 6:55 AM

Correct, it's made from cast iron, known for its durability in sealing applications.

Question by: Tammy T on Jun 16, 2025, 7:26 PM

groove depth on these things, what's the minimum I need to machine to so the ring don't bottom out when it compresses?

Answer by: Customer Support on Jun 18, 2025, 3:52 PM

Your groove has to be at least 0.015 inches deeper than the maximum radial wall thickness of the ring. On top of that, you need a tolerance of +0.003 inches on the deep side with no minus allowance. That extra room is what keeps the ring from bottoming out when it gets squeezed down to working diameter. Cut it short and you'll have sealing problems real quick.

Question by: Jerry R on Jul 8, 2025, 5:10 PM

got a piston groove cut for a 0.187 wide ring, is this the right size or am i gonna fight it?

Answer by: Customer Support on Jul 10, 2025, 1:09 PM

The groove width needs to be at least 0.001 inch wider than the ring’s maximum width, and it also needs to allow the ring to slide freely. Since this ring is 0.187 inches wide, you want a groove width that clears that by at least 0.001 inch, plus the stated tolerance of +0.003/-0.