3/8 inch x 5lb Lead to 15mm Copper Compression Coupling

The 3/8″ 5lb Lead to 15mm Copper Compression Coupling joins small bore lead to 15mm copper, with a grip for three-eighths inch lead of 5lb weight on one end and a 15mm compression joint on the other. It’s a brass Lead Line fitting for plumbers meeting old internal lead during a refit.

Three-eighths lead is the smallest you’re likely to meet. It was used for short branches inside older properties, such as the feed to a single tap, a WC cistern or an old copper boiler. When you find a length of it while refitting a kitchen or bathroom and want to get onto copper, this coupling makes the joint without any wiped lead work.

Small lead is soft and easy to squash, so cut it with a fine saw or cutter and gently round it back up. Check the weight, as the outside size changes with each. On the copper side, cut square, deburr, fit the nut and olive and tighten as you would any compression joint. Support the lead near the fitting. Lead this small inside the house is a good reason to strip it out, but until then the 3/8″ 5lb Lead to 15mm Copper Compression Coupling gets you connected. See our lead pipe connectors for other sizes.

Specification

• Brand: Lead Line
• Material: Brass
• Connection: 3/8 inch lead (5lb) x 15mm copper compression
• Sizes: 3/8 inch 5lb lead x 15mm copper
• Suitable for: Cold mains water supply pipe

Common Questions

What does the lb number on lead pipe mean? It’s the weight of the pipe per yard, and it tells you the wall thickness. Two pipes with the same bore but different weights have different outside diameters, so a set for one weight won’t grip the other properly.

How do I make the compression joint on the copper side? Cut the copper square and deburr it, slide on the nut and olive, push the pipe fully home and tighten until the olive grips, then a little more. Don’t overdo it, as the lead end needs gentle handling too.

Should I replace the lead pipe instead? Where you can, yes. Scottish Water advise replacing lead supply pipe, and a lead connector is best seen as a link between old and new until that’s done.

Does swapping lead for plastic affect the earthing? It can. If metal pipe that formed part of the earth path is replaced with plastic, the bonding needs checking and may need a jumper. Get an electrician to look if you’re unsure.

Order online or call in to 555 South Street, Glasgow G14 0QX. Counter hours are Mon-Fri 8am-5pm, Sat-Sun 8am-1pm.