McAlpine S12A-F 42mm Trap & Waste Thread Extension Adapter – 1 1/4″

McAlpine S12A-F 42mm Trap & Waste Thread Extension Adapter – 1 1/4″

Features

The McAlpine S12A-F 42mm Trap & Waste Thread Extension Adapter is a versatile, trade-quality fitting designed to solve tricky bathroom basin plumbing issues. This component features a standard 1 1/4″ BSP thread (which measures 42mm in outer diameter), making it perfect for customers looking to match or verify their existing pipe dimensions accurately.

It can be used as a short fixed extension piece to bridge awkward gaps, or as an adapter for irregular or extra-thick waste threads that standard traps won’t grip. Moulded from high-grade white polypropylene, it features a specialized flat internal face loaded with a thick, heavy-duty sealing washer. This unique design creates a secure, water-tight seal on non-standard fittings, leaving the bottom end perfectly prepped to accept any standard 42mm / 1 1/4″ waste trap.

• Genuine McAlpine fitting delivers commercial-grade reliability and a guaranteed leak-free seal
• 42mm actual thread diameter matches standard 1 1/4″ BSP UK bathroom basin plumbing
• Dual-purpose design acts as a short fixed extension spacer or a problem-solving thread adapter
• Flat internal face with a large, thick washer securely seals irregular or extra-thick waste threads
• Durable white polypropylene construction easily handles chemical cleaners and boiling water

Technical

• Thread Size Metric: 42mm Outer Diameter
• Thread Size Imperial: 1 1/4″ BSP (Standard Bathroom Basin Size)
• Design Feature: Flat internal face with heavy-duty washer
• Material: High-Grade Polypropylene
• Colour: White
• Connections: 42mm Female Thread (Top) to 42mm Male Thread (Bottom)
• Inclusions: Premium extra-large flat sealing washer

Details

When your bathroom basin leaks or needs a new trap, trying to figure out if you have a 1 1/4″ or a 1 1/2″ line can be incredibly confusing without a plumbing background. Ordering the wrong size means frustrating returns and a sink you can’t use. Furthermore, many unique designer basins feature thick ceramic bases or irregular waste threads that standard traps simply refuse to grip, leading to cross-threading and slow, hidden leaks inside your vanity unit.

The McAlpine S12A-F 42mm Adapter clears up the guesswork and solves the installation headache all at once. By explicitly matching your 42mm thread measurements, you can buy with confidence. Its specialized flat-face interior and extra-large washer crush down onto awkward or short threads to form a completely flat, watertight connection, allowing you to spin your trap into place in seconds.

Brand:

• McAlpine

MPN:

• S12A-F