14 Series 140A Micro Torch: Gas and Water Fitting Sizes Explained

By MIG/TIG/Stick Welders & Plasma Cutters | USA Weld – HTP ... | Published: 2026-11-05

Category: How-to Guides

Learn the exact gas and water fitting sizes on the 14 Series 140A water-cooled micro torch, plus a step-by-step setup to avoid leaks and mismatched connections.

Quick answer

The 14 Series 140A micro torch uses a 5/8-18 RH gas fitting, a 5/8-18 LH water supply fitting, and a 7/8-14 LH water return/current connection. Match each hose to its labeled port before tightening.

Why the left-hand threads matter

Water-cooled torches use left-hand threads on water lines to prevent accidentally connecting a water hose to the gas fitting. The 5/8-18 LH water supply and 7/8-14 LH return are designed this way; forcing a right-hand fitting will damage threads.

The gas fitting is right-hand (5/8-18 RH). If you try to thread a water hose onto it, the mismatch will be obvious—stop and check the label.

When a no-Dinse torch is the right choice

This 14 Series torch has no Dinse connector, so it relies on the welder’s built-in solenoid valve and a direct water return/current connection. That makes it a good fit for power sources already set up for water-cooled torches with a 7/8-14 LH return port.

If your welder uses a Dinse-style torch connection, you’ll need a different torch or an adapter—check your machine’s torch connection before ordering.

Step-by-step fitting setup

Identify each port on the torch: Locate the gas fitting (5/8-18 RH), water supply fitting (5/8-18 LH), and water return/current connection (7/8-14 LH). Most torches have markings or a colored ring; if not, consult the manual. Label hoses with tape if the ports are not clearly marked.
Match hoses to ports by thread direction: Thread a right-hand hose onto the gas fitting and left-hand hoses onto the water fittings. Turn counterclockwise to tighten left-hand threads. If a hose starts easily but binds after one turn, you likely have the wrong port—stop immediately.
Hand-tighten first, then snug with a wrench: Start all fittings by hand to avoid cross-threading. Then use a wrench to snug them—about 1/8 to 1/4 turn past hand-tight. Do not overtighten; it can crush seals or distort the torch body. Overtightening is the most common cause of leaks at the torch head.
Connect the water return/current lead: Attach the 7/8-14 LH return/current connection to the matching port on your welder or cooler. Ensure the connection is fully seated before tightening. A loose return connection can cause arcing and poor weld quality.
Pressure-test the system: Turn on the coolant flow and check for leaks at all connections. Wipe each fitting dry, run the pump for 30 seconds, and look for drips. Tighten slightly if needed. Never start welding with a known leak—coolant can damage the torch and create a shock hazard.

Product facts

14 Series (140A) Water-Cooled Micro Torch w/No Dinse, 5/8"-18 RH Gas Fitting, & 5/8"-18 LH Water-Cooler Fittings: 14 Series (140A) water-cooled micro torch with 5/8-18 RH gas fitting, 5/8-18 LH water supply fitting, and 7/8-14 LH water return/current connection. These exact sizes let you verify hose compatibility before installation, avoiding leaks or damaged threads.
14 Series (140A) Water-Cooled Micro Torch w/No Dinse, 5/8"-18 RH Gas Fitting, & 5/8"-18 LH Water-Cooler Fittings