Sioux Chief 637XG721 1/2" PEX x 3/8" OD No-Lead Compression Adapter

Sioux Chief 637XG721 1/2" PEX x 3/8" OD No-Lead Compression Adapter

The Sioux Chief 637XG721 is a no-lead adapter built to connect 1/2" PEX tubing to a 3/8" O.D. compression fitting, giving plumbers and contractors a direct transition for lavatory and sink supply hookups. The fitting is designed for behind-the-wall and under-fixture rough-in work, where a compact PEX-to-compression connection is needed without adding a separate reducing coupling. Its lead-free solder joint keeps the connection point no-lead, and the compression end is sized to standard 3/8" O.D. supply tube commonly used at stop valves. This adapter is purpose-built for quick lav and sink supply installs rather than general-purpose DWV or main distribution work.

Key Features

• Trade Size: 1/2" PEX inlet x 3/8" O.D. compression outlet, sized to match standard lavatory and sink supply stops without an additional reducer.
• PEX to Compression Transition: Connects PEX tubing directly to 3/8" O.D. compression tube, letting installers move from a PEX branch line straight to a compression supply connection at the fixture.
• No-Lead Construction: Features a lead-free solder joint at the connection point, consistent with the no-lead designation on the part.
• Installation Note: Do not apply pipe dope to the compression threads — the compression connection is designed to seal without it.
• Application-Ready Sizing: Sized and configured specifically for lav/sink supply hookup applications, making it a straightforward pick for finish-out plumbing near the fixture stop.

Technical Specifications

• Product Type: Adapter
• Country of Origin: United States
• Packaging: 20 EA

Typical Applications

• Lavatory Supply Line Hookups
• Sink Supply Line Connections
• PEX to Compression Tubing Transitions
• Residential and Commercial Rough-In Plumbing
• Stop Valve to PEX Branch Line Connections

Why Sioux Chief?

Sioux Chief manufactures this adapter with a lead-free solder joint and a precise 1/2" PEX x 3/8" O.D. compression fit, giving installers a dependable, purpose-sized connector for lav and sink supply hookups. The no-lead construction and compression-ready threading are built for straightforward rough-in transitions between PEX distribution lines and compression supply fittings, without requiring pipe dope or extra reducing parts. For plumbers standardizing on PEX distribution with compression stops, this adapter offers a direct, code-focused way to complete the transition at the fixture.