1/2" (13Mm) Poly Washers

1/2" (13Mm) Poly Washers

1/2" Poly Washers are essential plumbing gaskets used to create a watertight seal between a 1/2" BSP (British Standard Pipe) female fitting and a flat-faced male connection. While often referred to as 13mm, they are specifically designed for the industry-standard 1/2" thread size found in domestic plumbing.

Unlike rubber washers which can perish or fiber washers which can swell, Polyethylene (Poly) washers are rigid yet slightly compressible. They offer excellent chemical resistance and do not degrade when exposed to the various additives found in modern central heating systems.

Key Features and Specifications

Size: 1/2" BSP (Internal Diameter approx. 13mm).

Material: Semi-rigid White Polyethylene (Poly).

Compatibility: Ideal for cold and hot water systems, as well as glycol-mixed heating circuits.

Sealing Properties: Provides a durable, non-stick seal that is easy to remove during future maintenance compared to fiber washers.

Temperature Rating: Suitable for standard domestic hot water and heating temperatures.

Quantity: Typically available in trade packs of 10, 50, or 100.

Common Applications

Tap Connectors: Providing a seal inside 1/2" flexible tap tails or rigid nut-and-olive tap connectors.

Radiator Valves: Used on the union nut of a manual or thermostatic radiator valve (TRV) to seal against the radiator tail.

Shower Hoses: Often used in shower hose nuts to prevent leaks at the handset or mixer valve connection.

Filling Loops: Sealing the connection points on flexible boiler filling loops.

Essential Companion Products

Threaded Fittings: 1/2" Brass Blanking Cap

Valves: 15mm x 1/2" Straight Manual Radiator Valve

Alternative Material: 1/2" Rubber Washers (for lower pressure/flexible seals)

Lubricant: Silicone Grease (to prevent O-ring/washer twisting)

Specialist Support and Local Collection

Leaking tap or radiator valve? Using the correct washer is the simplest way to ensure a long-term fix. We stock a full range of washers in Poly, Fiber, and Rubber for 3/8", 1/2", 3/4", and 1" connections.

Visit our trade counter at 61 Fullers Road, E18 2QB for immediate collection and to grab a trade pack for your toolbox.