TW400 Gas Cooled MIG Welding Torch Welding Gun - Changzhou Inwelt

TW400 Tweco-Style MIG Welding Gun Overview

The INWELT TW400 Tweco-Style MIG Welding Gun is a 400A gas-cooled MIG/MAG welding torch designed for industrial fabrication, equipment manufacturing, maintenance and replacement applications.

The TW400 is rated at 400A with CO₂ shielding gas and 350A with mixed shielding gas at a 60% duty cycle. It supports Ø0.8–2.0 mm welding wire and is available with several cable lengths and rear-adapter configurations.

Built around a Tweco-style front-end consumable system, the TW400 features replaceable contact tips, gas nozzles, gas diffusers, insulators and torch components. This allows buyers to identify individual replacement parts instead of treating the welding gun as a single non-serviceable assembly.

INWELT supplies TW400 complete MIG welding guns and corresponding spare parts for welding equipment distributors, importers, industrial users and OEM/ODM customers.

TW400 MIG Welding Gun Technical Specifications

The following specifications describe the current INWELT TW400 product range.

Specification	INWELT TW400
Brand	INWELT
Model	TW400 / TW4
Product Code	ICT5900
Product Type	Tweco-Style MIG Welding Gun
Welding Process	MIG/MAG (GMAW)
Cooling Method	Gas Cooled / Air Cooled
Rated Current with CO₂	400A
Rated Current with Mixed Gas	350A
Duty Cycle	60%
Welding Wire Diameter	Ø0.8–2.0 mm
Listed Standard Cable Assemblies	3 m / 4 m / 5 m
Other Cable Lengths	Subject to configuration confirmation
Front-End Consumables	Tweco-Style
Connector Configurations	Standard / Euro / Miller Adapter
Gas Nozzle	Ø16 mm standard listed option
Standard Listed Contact Tip	Ø1.2 mm, 1/4-28 thread
Application	Industrial Manual MIG/MAG Welding
Supply Options	Wholesale / OEM / ODM

The current rating must be considered together with the shielding gas, duty cycle and operating conditions.

For replacement orders, buyers should confirm the cable length, connector configuration, welding-wire diameter and corresponding front-end consumables.

Key Features of the INWELT TW400 MIG Gun

400A CO₂ and 350A Mixed-Gas Current Ratings

The TW400 has two published welding-current ratings:

• 400A with CO₂ shielding gas

• 350A with mixed shielding gas

Both ratings are specified at a 60% duty cycle.

These separate values help buyers select the torch according to their welding process instead of assuming that the maximum current applies under every shielding-gas condition.

The appropriate welding setup should be determined using the required current, welding wire, shielding gas, duty cycle and welding procedure.

Gas-Cooled Design for Industrial MIG Welding

The TW400 uses a gas-cooled, also commonly described as air-cooled, torch design.

Unlike a water-cooled MIG welding gun, it does not require a separate liquid-cooling circuit.

This design can be practical for manual fabrication and maintenance work where equipment mobility and straightforward installation are important.

A gas-cooled torch must still be operated within its specified thermal rating. For long-duration, high-current applications, buyers should evaluate whether a water-cooled configuration would be more suitable.

Replaceable Tweco-Style Front-End Consumables

The TW400 uses a serviceable front-end configuration that includes a contact tip, gas nozzle, diffuser and insulator.

These components perform different functions:

• Contact Tip: Transfers welding current to the electrode wire.

• Gas Nozzle: Directs shielding gas around the welding arc.

• Gas Diffuser: Distributes shielding gas through the front-end assembly.

• Insulator: Provides electrical separation between designated components.

Correct installation and component matching are necessary for consistent welding operation.

Industrial Handle and Trigger Assembly

The TW400 uses an industrial MIG handle with a trigger switch and replaceable cable-support components.

The handle allows the operator to position and control the torch during manual welding.

The trigger, handle, cable support and rear connection should be inspected as part of routine maintenance.

For replacement applications, the handle and trigger components must correspond to the selected TW400 assembly.

Understanding the TW400 60% Duty Cycle

The INWELT TW400 is rated at a 60% duty cycle under its specified current and shielding-gas conditions.

Duty cycle describes the proportion of a standard operating period during which a welding gun may operate at its rated load under defined test conditions.

In the commonly used ten-minute duty-cycle reference period, 60% represents six minutes of welding and four minutes without welding at the specified load.

TW400 with CO₂ Shielding Gas

• Welding current: 400A

• Shielding gas: CO₂

• Duty cycle: 60%

TW400 with Mixed Shielding Gas

• Welding current: 350A

• Shielding gas: Mixed gas

• Duty cycle: 60%

A 400A model designation does not mean the TW400 can operate continuously at 400A.

If the intended welding operation requires a higher duty cycle or sustained high-current operation, the complete thermal requirements should be reviewed before selecting the torch.

TW400 MIG Gun Cable Lengths and Connector Options

INWELT lists different TW400 complete torch assemblies to accommodate welding equipment connection requirements.

The current complete-torch references include 3 m, 4 m and 5 m cable lengths.

Standard, Euro and Miller Adapter Configurations

The available configuration groups are:

Standard TW4 Configuration

The standard TW4 assembly is intended for the corresponding connection system. Exact rear-connector dimensions should be confirmed for the customer's welding equipment.

TW4 with Euro Adapter

Euro-adapter versions are listed for the TW400. Compatibility should be verified against the actual wire feeder and power-source interface.

TW4 with Miller Adapter

Miller-adapter versions are also listed. The correct adapter and trigger-control connection must be matched to the specific welding machine or wire feeder.

A connector described as Miller-style or Euro-style should not be assumed to fit every machine from that equipment category.

TW400 Complete Torch Part Numbers

INWELT Code	Reference	Description	Length
IJDU5911	410-3545	TW4 Standard Torch	3 m
IJDU5917	412-3545	TW4 Standard Torch	4 m
IJDU5918	415-3545	TW4 Standard Torch	5 m
IJDU5926	X410-3545	TW4 with Euro Adapter	3 m
IJDU5922	X412-3545	TW4 with Euro Adapter	4 m
IJDU5923	X415-3545	TW4 with Euro Adapter	5 m
IJDU5924	M410-3545	TW4 with Miller Adapter	3 m
IJDU5925	M412-3545	TW4 with Miller Adapter	4 m
IJDU5931	M415-3545	TW4 with Miller Adapter	5 m

These references are useful for distributors, repeat orders and replacement welding-gun sourcing.

For a 5 m or other nonstandard cable requirement, confirm the available configuration and complete-torch code before ordering.

How to Choose the Correct Cable Length

3 m TW400 MIG Gun

Suitable for relatively compact workstations where the wire feeder is positioned close to the welding area.

4 m TW400 MIG Gun

Provides additional working reach for general fabrication and industrial workshop applications.

5 m TW400 MIG Gun

Suitable for larger work areas where the operator requires more distance from the wire feeder.

When selecting a cable length, consider wire-feed resistance, cable handling, workpiece size and operator movement.

TW400 MIG Welding Gun Consumables and Spare Parts

The TW400 uses replaceable consumables and mechanical components that should be selected according to the actual torch configuration.

INWELT provides corresponding product codes and reference numbers to support component identification.

TW400 Consumables and Replacement Parts Table

Component	INWELT Code	Reference / Specification
Gas Nozzle	UDT0602	24A-62 / Ø16 mm
Insulator	IJDL0697	34A
Contact Tip	IJDV0010-12	14-116 / Ø1.2 mm / 1/4-28 × 37.4 mm
Gas Diffuser	IJDG0081	54A
Torch Head	IJDA0600-01	TW4 / 60GR / 64J-60
MIG Handle	IJDW0704	84A
Trigger Kit	IJIR0092	TW Trigger Kit
Handle Joint	IJIK0788	MIG Handle Joint
Cable Support Spring	IJGU0887-02	TW Cable Support
Cable Assembly	IJD00919	3 m Cable Assembly
Rear Support Spring	IJGU0835	Cable Support Component
Rear Housing	IJIK0883	Back Box with Closing Ring
Screw	IJGU0074	M4 × 6
Miller-Type Adapter Component	IJAI7062	Miller M10 × 1 Configuration
Connecting Adapter	IJUP0003	TW1–4 Connection Adapter
Steel Liner	IJJD0010-03	3.4 m / Ø0.9–1.2 mm

The references above describe the listed TW400 configuration. Alternative wire diameters, cable lengths and connector types may require different components.

Buyers should confirm the corresponding part number, dimensions and reference sample before bulk purchasing.

TW400 Gas Nozzles and Contact Tips

The standard TW400 gas nozzle listed by INWELT is:

• Part: Gas Nozzle

• Nozzle Diameter: Ø16 mm

• Reference: 24A-62

• INWELT Code: UDT0602

The standard listed contact tip is:

• Part: MIG Contact Tip

• Welding Wire Diameter: Ø1.2 mm

• Reference: 14-116

• Thread: 1/4-28

• Length: 37.4 mm

• INWELT Code: IJDV0010-12

The contact-tip size should match the actual welding wire diameter.

For wire sizes other than Ø1.2 mm, a corresponding contact tip must be selected and verified.

TW400 Diffusers, Insulators and Torch Heads

The TW400 front-end assembly includes:

• Gas Diffuser: 54A

• Insulator: 34A

• Torch Head: TW4 / 60GR / 64J-60 configuration

The diffuser, insulator and torch head must match the selected nozzle and contact-tip system.

Do not assume that similarly named components from different welding-gun generations or manufacturers are interchangeable.

TW400 Wire Liners, Handles and Trigger Parts

The currently listed standard steel liner is specified for Ø0.9–1.2 mm welding wire with a 3.4 m length.

Although the complete TW400 torch has a listed wire capacity of Ø0.8–2.0 mm, the standard Ø0.9–1.2 mm liner is not suitable for every wire diameter in that range.

Liners should be selected according to:

• Welding wire diameter

• Welding wire material

• Cable length

• Torch configuration

• Wire feeder setup

The trigger kit, handle and cable support components should also be matched by model and reference number.

Is the INWELT TW400 Compatible with Tweco-Style MIG Guns?

The INWELT TW400 is designed around a Tweco-style MIG welding gun configuration.

It uses consumable formats and mechanical arrangements commonly associated with the TW4-style front-end system.

However, Tweco-style does not mean universal interchangeability with every Tweco welding gun or welding machine.

Compatibility should be confirmed using component dimensions, part numbers and equipment connection requirements.

TW400 Compatibility Checklist

Item	What to Verify
Existing Welding Gun	Model and configuration
Power Source	Manufacturer and model
Wire Feeder	Connector arrangement
Rear Connector	Standard / Euro / Miller configuration
Trigger Connection	Electrical control interface
Cable Length	Required operating reach
Contact Tip	Thread, length and wire diameter
Gas Nozzle	Diameter and attachment style
Gas Diffuser	Required front-end configuration
Wire Liner	Wire size and cable length
Torch Head	Neck and component arrangement

For replacement orders, provide photographs of the existing welding gun and connector, together with the relevant part numbers or technical drawings.

INWELT is an independent welding torch manufacturer. The description “Tweco-style” indicates a compatible design category and does not establish affiliation with, endorsement by or universal interchangeability with the original brand.

---

Technical Data:

Position	Code	Ref.	Description
1	UDT0602	24A-62	Gas nozzle Φ16
2	IJDL0697	34A	Insulator
3	IJDV0010-12	14-116	Contact tip Φ1.2mm/ 1/4-28X37.4
4	IJDG0081	54A	Diffuser
5	IJDA0600-01		5 Torch head 60GR/TW4/64J-60/Nickel-plated outer tube
6	IJDW0704	84A	MIG handle with screw
7	IJIR0092		Trigger Kit/TW
8	IJIK0788		Joint for MIG handle
9	IJGU0887-02		Spring for cable support/Zin/Long/TW
10	IJD00919		Cable assembly/3M
11	IJGU0835		Spring for cable support/Blue and white zinc plating
12	IJIK0883		Back box with closing ring
13	IJGU0074	EA0018	Screw M4x6
14	IJAI7062		Continental adapter / Miller M10X1
15	IJUP0003		Connetecing adaptor TW1-4
16	IJJD0010-03		Steel liner 3.4M Φ0.9-1.2mm/TW
Complete Torch
	IJDU5911	410-3545	TW4 Torch 3m
	IJDU5917	412-3545	TW4 Torch 4m
	IJDU5918	415-3545	TW4 Torch 5m
	IJDU5926	X410-3545	TW4 Torch 3m euro adaptor
	IJDU5922	X412-3545	Tw4 Torch 4m euro adaptor
	IJDU5923	X415-3545	Tw4 Torch 5m euro adaptor
	IJDU5924	M410-3545	Tw4 Torch 3m Miller adaptor
	IJDU5925	M412-3545	Tw4 Torch 4m Miller adaptor
	IJDU5931	M415-3545	Tw4 Torch 5m Miller adaptor

---

How to Choose the Correct TW400 MIG Welding Gun

A TW400 welding gun should be selected according to the complete welding application rather than current rating alone.

Step 1: Confirm Welding Current and Shielding Gas

Check the required welding current.

The TW400 is specified at 400A CO₂ or 350A mixed gas, both at a 60% duty cycle.

Step 2: Confirm the Welding Wire Diameter

The TW400 supports Ø0.8–2.0 mm welding wire.

Contact tips, liners and wire-feed components must match the selected wire size.

Step 3: Choose the Cable Length

Select a standard 3 m, 4 m or 5 m assembly according to the working distance.

For alternative lengths, confirm the available configuration.

Step 4: Verify the Rear Connector

Select the required standard, Euro or Miller-adapter configuration only after confirming the welding-machine interface.

Step 5: Check the Front-End Consumables

Verify the gas nozzle, contact tip, diffuser, insulator and torch head.

Step 6: Confirm Spare Parts and Order Quantity

For distributors and OEM buyers, confirm the complete torch codes and replacement consumables before placing bulk orders.

TW200 vs. TW300 vs. TW400 MIG Welding Guns

The INWELT TW Series includes three principal gas-cooled MIG welding gun models.

Specification	TW200	TW300	TW400
Cooling	Gas Cooled	Gas Cooled	Gas Cooled
CO₂ Current	200A	300A	400A
Mixed-Gas Current	150A	250A	350A
Duty Cycle	60%	60%	60%
Welding Wire Range	Ø0.6–1.2 mm	Ø0.8–1.6 mm	Ø0.8–2.0 mm
Product Category	MIG/MAG	MIG/MAG	MIG/MAG

When Should You Choose TW200?

Choose TW200 when the welding operation requires a lower current rating and the specified wire size is within Ø0.6–1.2 mm.

When Should You Choose TW300?

Choose TW300 when the application requires a higher current capacity than TW200 and uses welding wire within Ø0.8–1.6 mm.

When Should You Choose TW400?

Choose TW400 when the application requires up to 400A with CO₂ or 350A with mixed gas at the specified 60% duty cycle, with a wire-size range up to Ø2.0 mm.

Actual selection should also account for the welding process, connector, cable configuration and consumables.

Industrial Applications of the TW400 MIG Welding Gun

The TW400 is intended for manual industrial MIG/MAG welding applications within its stated operating limits.

Structural Steel Fabrication

The TW400 can be considered for structural steel welding and fabrication where the welding procedure requires a compatible gas-cooled MIG welding gun.

Machinery and Equipment Manufacturing

Industrial machinery production may involve repeated MIG/MAG welding of frames, housings and other fabricated components.

The torch should be selected according to the actual current, wire diameter and operating duration.

Truck and Trailer Fabrication

The TW400 can be evaluated for compatible welding tasks involving truck frames, trailers and fabricated vehicle components.

Cable length and torch accessibility are important considerations when working around large assemblies.

Heavy Equipment Repair

Industrial repair operations often involve welding around large or difficult-to-position workpieces.

A suitable cable length and rear connector configuration can help adapt the welding gun to the existing workstation.

General Industrial Welding

The TW400 may also be used in industrial fabrication workshops where the required current and duty cycle are within its specifications.

Common TW400 MIG Gun Problems and Solutions

MIG welding-gun problems may result from consumable wear, electrical connections, wire-feed conditions or operating parameters.

Problem	Possible Cause	Recommended Check
Torch overheating	Excessive current or duty cycle	Verify welding current and thermal rating
Contact tip burnback	Incorrect contact tip or wire-feeding problem	Check tip size, feed settings and stickout
Irregular wire feeding	Worn liner or excessive cable bending	Inspect liner, cable routing and drive rolls
Poor shielding-gas coverage	Blocked nozzle or gas leakage	Inspect nozzle, diffuser and gas connections
Unstable welding arc	Worn tip or poor electrical connection	Inspect contact tip and conductor connections
Excessive spatter	Welding parameter or shielding-gas issues	Check process settings and consumables
Trigger not operating	Trigger or control-connection problem	Inspect switch and connector
Cable overheating	Damaged conductor or loose connection	Inspect and replace damaged components

Why Does a TW400 MIG Welding Gun Overheat?

Possible causes include current or duty-cycle overload, loose electrical connections, damaged conductors and worn consumables.

Stop welding and allow the gun to cool before inspection.

Why Does the TW400 Have Wire Feeding Problems?

Common causes include incorrect liner size, a worn contact tip, poor cable routing or unsuitable wire-feeder settings.

Verify that the liner and contact tip correspond to the selected wire diameter.

Why Is the TW400 MIG Arc Unstable?

Arc instability may be associated with inconsistent wire feeding, contact-tip wear, poor electrical contact or unsuitable welding parameters.

Inspect the welding gun and the complete wire-feeding system before replacing the torch assembly.

TW400 MIG Gun Maintenance and Consumable Replacement

Regular inspection helps keep the TW400 in appropriate working condition.

Inspect the Contact Tip

Check the contact-tip bore for wear, deformation and excessive contamination.

Replace the tip when its condition affects welding-current transfer or wire feeding.

Clean the Gas Nozzle

Remove excessive spatter buildup from the nozzle opening using a suitable cleaning method.

Replace damaged or deformed nozzles.

Check the Gas Diffuser and Insulator

Inspect the diffuser and insulator for visible damage, contamination or incorrect installation.

Inspect the Wire Liner

Check the liner when wire feeding becomes irregular or excessive resistance is observed.

Select a replacement liner according to wire size and cable length.

Inspect the Cable and Connector

Look for loose connections, cable damage, worn support springs and excessive bending.

Check the Handle and Trigger

Verify that the trigger operates correctly and inspect the handle for mechanical damage.

Disconnect the welding equipment and allow the gun to cool before inspecting or replacing components.

---

Our Catalog:

INWELT MIG WELDING TORCH.pdf

---

TW400 MIG Welding Guns for Distributors and OEM Buyers

INWELT supplies TW400 MIG welding guns for international welding equipment distributors, importers, wholesalers and industrial buyers.

Available purchasing discussions include:

• Standard TW400 complete welding guns

• Euro-adapter configurations

• Miller-adapter configurations

• Multiple cable lengths

• Tweco-style replacement consumables

• Spare parts supply

• Bulk purchasing

• OEM/ODM production

• Private-label packaging

• Product marking and packaging requirements

OEM and Private-Label TW400 MIG Guns

For OEM projects, INWELT can review requirements relating to cable assemblies, connector configurations, product appearance, branding and packaging.

Customization requests should be supported by technical drawings, reference samples or complete specifications.

Wholesale TW400 Welding Guns and Consumables

For distributor inventory management, TW400 complete torches can be identified by their specific assembly codes.

Replacement consumables can be organized by nozzle, tip, diffuser, insulator, torch head and liner references.

This model-based approach helps buyers maintain consistent purchasing specifications across repeat orders.

Why Source TW400 MIG Welding Guns from INWELT?

INWELT manufactures and supplies MIG, TIG and plasma cutting torches and related welding accessories for professional B2B customers.

For TW400 projects, buyers can discuss complete welding-gun specifications, connector options, cable length requirements, matching consumables and OEM/ODM supply within one purchasing process.

Frequently Asked Questions About TW400 MIG Guns

What is a TW400 MIG welding gun?

The INWELT TW400 is a Tweco-style gas-cooled MIG/MAG welding gun rated at 400A with CO₂ and 350A with mixed shielding gas at a 60% duty cycle.

Is the TW400 a 400A MIG welding gun?

Yes. The INWELT TW400 is rated at 400A with CO₂ shielding gas at a 60% duty cycle. Its mixed-gas rating is 350A at the same specified duty cycle.

Is the TW400 air-cooled or water-cooled?

The TW400 is air-cooled, also referred to as gas-cooled. It does not require a separate liquid-cooling circuit.

What welding wire sizes does the TW400 support?

The listed welding-wire range is Ø0.8–2.0 mm. Correct contact tips, liners and wire-feeding components must be selected for each wire diameter.

What cable lengths are available for the TW400?

The current standard complete-torch list includes 3 m, 4 m and 5 m assemblies. Other lengths should be confirmed according to the required configuration.

Can the TW400 be supplied with a Euro connector?

Yes. INWELT lists TW400 Euro-adapter configurations. Buyers should verify the exact interface against their welding machine or wire feeder.

Are Miller-adapter TW400 MIG guns available?

Yes. The listed complete-torch range includes Miller-adapter configurations in multiple cable lengths. Specific equipment compatibility must be confirmed.

What contact tip does the standard TW400 use?

The current INWELT parts list includes a Ø1.2 mm contact tip with a 1/4-28 thread and 37.4 mm length, reference 14-116.

What gas nozzle does the TW400 use?

The standard listed nozzle is Ø16 mm, reference 24A-62.

What gas diffuser does the TW400 use?

The current front-end parts list includes a 54A gas diffuser.

Can I use Ø2.0 mm wire with the standard TW400 liner?

The TW400 has a listed wire-capacity range up to Ø2.0 mm, but its standard listed steel liner is for Ø0.9–1.2 mm wire. A suitable liner and matching wire-feed setup must be confirmed for Ø2.0 mm applications.

Is the INWELT TW400 interchangeable with every Tweco MIG gun?

No. The TW400 uses a Tweco-style configuration, but the actual connector, consumable dimensions, torch head and electrical connections must be verified for the specific replacement application.

What is the difference between TW300 and TW400?

The TW300 is rated at 300A CO₂ and 250A mixed gas, while the TW400 is rated at 400A CO₂ and 350A mixed gas. Both are listed at a 60% duty cycle.

Does INWELT supply TW400 spare parts?

Yes. INWELT lists corresponding TW400 contact tips, nozzles, diffusers, insulators, torch heads, handles, triggers and cable components.

Can INWELT provide OEM TW400 MIG welding guns?

INWELT supports OEM/ODM inquiries for TW400 welding guns, including connector, cable, branding, packaging and bulk purchasing requirements.

Request a TW400 MIG Welding Gun Quote

Looking for a TW400 Tweco-style MIG welding gun manufacturer or wholesale supplier?

INWELT supplies complete TW400 gas-cooled MIG welding guns, replacement consumables and OEM/ODM solutions for international B2B buyers.

For an accurate quotation, please provide:

• Required model: TW400

• Welding machine and wire feeder model

• Connector type: Standard / Euro / Miller

• Cable length: 3 m / 4 m / 5 m or requested custom length

• Welding wire diameter

• Shielding gas and required welding current

• Consumable or spare parts requirements

• Order quantity

• OEM/ODM requirements

• Destination market

Contact INWELT for TW400 MIG Welding Gun Specifications, Replacement Parts, Wholesale Pricing and OEM/ODM Inquiries.