As an Amazon Associate, Garage Welding may earn from qualifying purchases. This does not change the price you pay.
The WeldingCity 23-37 gas nozzle is a replacement MIG nozzle with a 3/8 in. orifice, listed for Lincoln 300-400 and Tweco Professional #3 style guns. It is worth considering if you run one of those larger guns and need a smaller opening for tight access. Skip it if you weld at high amperage in open joints, where a larger orifice usually covers better. This review is based on the Amazon listing and general MIG practice, not hands-on testing.
WeldingCity 23-37 at a Glance
| Item | Per the listing |
|---|---|
| Part number | 23-37 |
| Orifice | 3/8 in. (listing shows 1/2, 5/8 and 3/4 in. as other sizes) |
| Style | Thread-on gas nozzle |
| Gun families named | Lincoln 300-400, Tweco Professional #3 |
| Intended duty | Medium to heavy duty MIG |
| Pack quantity | Check the listing |
Prices change, so check the current listing.
Check the WeldingCity 23-37 nozzle on Amazon →
What It Is and Who It Suits
The gas nozzle is the outer cup that guides shielding gas around the arc and protects the contact tip and diffuser from heat and spatter. Nozzle size is a trade-off:
- Smaller orifice (3/8 in.): better access in corners and tight joints; concentrates gas but covers a narrower area.
- Larger orifice (1/2 in. and up): better coverage at higher amperage; more difficult in tight spots.
This version suits welders running larger 300 to 400 A class guns who sometimes need a narrow nozzle for access. If you only weld in open positions at high amps, a larger nozzle may be the better main choice.
How to Check It Fits Your Gun
- Identify your gun. Tweco Professional #3 and Lincoln 300-400 style guns share a consumable family. Check the model on the gun or in the manual.
- Look at the old nozzle. Check whether it is thread-on or slip-on, and compare the thread and length.
- Check the diffuser. The nozzle seats on the diffuser. A worn or wrong diffuser will leak gas or let the nozzle wobble.
- Choose the orifice. Match the opening to your amperage and joint access. Keep 3/8 in. for narrow work.
- Mind the recess. Nozzle length changes where the contact tip sits relative to the opening. Follow your gun maker’s settings for the process you use.
View the current nozzle listing →
Pros and Limitations
Pros
- Thread-on design is simple to fit and replace.
- Small orifice helps in tight joints.
- Covers two common gun families according to the listing.
Limitations
- Not the best choice for high-amperage open joints.
- Fit is limited to the guns named; verify before ordering.
- Claims about speed or life-span gains cannot be verified.
- A small orifice clogs faster with spatter.
Use and Care Tips
- Unplug the welder and let the gun cool before changing the nozzle.
- Clean spatter with a nozzle reamer or pliers, not by scraping with a tool that can damage the bore.
- Use anti-spatter product sparingly and wipe off any excess that could block gas ports.
- Check for gas leaks after installation. A poor seat causes porosity.
- Replace the nozzle if it is cracked, deformed or loose.
- Match your shielding gas to the wire. Mild steel solid wire commonly uses 75/25 argon/CO2.
- Wear a proper helmet, gloves and flame-resistant clothing and ventilate.
Alternatives and Related Guides
- Other nozzle options: MIG gun nozzles review and PK MIG welding nozzle N-5818C review.
- Match contact tips: WeldingCity contact tips review.
- Check the whole gun: Lincoln SP series MIG gun review.
Frequently Asked Questions
What does the 3/8 in. size on a 23-37 nozzle mean?
It refers to the inside diameter of the nozzle opening. A smaller orifice concentrates gas and fits tight joints, while larger orifices (1/2, 5/8, 3/4 in.) cover a wider area and suit higher amperage. Choose by joint access and the amperage you weld at.
Which MIG guns does this nozzle fit?
The listing says Lincoln 300-400 and Tweco Professional #3 style guns. Gun series differ by diffuser and thread, so confirm your gun model and compare the nozzle seat and thread with your existing nozzle before buying.
Is a 3/8 in. nozzle good for heavy-duty welding?
The listing describes medium-to-heavy duty use, but a 3/8 in. orifice is the smaller option. At high amperage, many welders choose a larger orifice for better shielding gas coverage and to keep the tip cooler. Follow your gun maker guidance.
Can I use it for aluminum or stainless?
The nozzle only directs gas, so material depends on your wire, gas and machine. Aluminum needs 100% argon and soft-wire feeding gear; stainless needs the correct wire and gas mix. The nozzle must also suit your gun and amperage range.
Verdict
A reasonable replacement or narrow-access nozzle if your gun is a Lincoln 300-400 or Tweco #3 style. Check thread and diffuser fit first and pick the orifice size that suits your amperage.
See the WeldingCity 23-37 nozzle on Amazon →
