Larsen Supply Co. 118737 Cone Washer 3/8 Inch Od 4 Pack

Product Description

The LARSEN SUPPLY CO., INC. 118737 is a 4-pack of No. 9 rubber stepped cone washers designed to seal the connection between a ballcock nut and a 3/8 inch OD metal supply tube. These washers are specifically suited for older-style metal toilet supply line installations where tapered cone-style compression seals are required. The stepped cone profile creates a reliable watertight seat against the ballcock inlet shank, preventing drips at the tank connection point. Weighing just 0.22 pounds for the packaged set, this is a straightforward service part that plumbers and maintenance technicians keep on hand for toilet rebuild and valve replacement work.

These cone washers are used in residential and light commercial plumbing applications involving older metal toilet supply tubes connected to ballcock fill valves. The 3/8 inch OD sizing is standard for the tapered inlet shanks found on traditional ballcock assemblies. They are commonly installed during toilet tank repairs, ballcock replacements, or supply line reconnections where the original rubber washer has hardened, cracked, or deformed and is no longer sealing properly. The carded 4-pack format makes this a practical stock item for service vans and supply houses.

Key Features

• No. 9 stepped cone profile seats correctly against ballcock inlet shank tapers
• Sized for 3/8 inch OD metal supply tubes
• Rubber construction resists water and maintains a watertight seal
• 4 washers per pack — practical quantity for service calls
• Designed for old-style metal supply tube connections

Compatibility

Designed for use with old-style metal toilet supply tubes connecting to ballcock nut inlets with a 3/8 inch OD tube fitting. Suitable for traditional ballcock fill valve assemblies that use a stepped cone washer seal at the shank connection.

Installation Notes

Installation is performed by a licensed plumber or qualified maintenance technician. Shut off the water supply at the stop valve and flush the toilet to relieve pressure before disconnecting the supply tube. Seat the cone washer into the ballcock nut with the stepped taper facing the inlet shank, then hand-tighten the nut before applying a final quarter-turn with pliers — do not overtighten, as this can damage the rubber washer or crack the ballcock shank. Follow applicable local plumbing codes, referencing IPC guidelines where required.