Therwen 48 Pcs Flux Core Nozzle Kit review

Are you looking for a reliable Flux Core Gasless Nozzle Tips kit to keep your MIG gun performing at its best?

Product Overview

You get a substantial accessory set with the Therwen 48 Pcs Flux Core Gasless Nozzle Tips Kits KP1939-1 Flux Core Welder Mig Welder Contact Tips Gasless Nozzle Gas Diffusers for Mig Gun(48 Pcs,0.030″(0.8mm) kit, 0.035″(0.9mm) kit). The package is designed to give you plenty of spares for regular welding work and quick replacements, so you can spend more time welding and less time hunting for parts.

What’s included

The kit contains 4 flux core gasless nozzles (KP1939-1), 20 conductive contact tips sized 0.030″ (0.8 mm), 20 conductive contact tips sized 0.035″ (0.9 mm), and 4 gas diffusers. Those quantities mean you have enough parts to cover routine wear, occasional damage, or separate projects that need different tip sizes.

Key Specifications

Below is a quick breakdown of the most relevant specifications so you can check fit and function quickly. This table helps you verify compatibility at a glance and understand exactly what each piece in the kit is intended for.

Component	Quantity	Diameter/Size	Material	Notes
KP1939-1 Gasless Nozzle	4	N/A	Brass/Copper	Flux-core specific gasless nozzle
Contact Tips (0.030″)	20	0.030″ (0.8 mm)	Copper	For thinner wire/precision work
Contact Tips (0.035″)	20	0.035″ (0.9 mm)	Copper	Common size for flux core welding
Gas Diffusers	4	N/A	Brass/Copper	Helps distribute gas or act as spacer in some setups
Kit Total	48	N/A	Brass/Copper	Enough spares for months of hobby or light professional use

Performance and Welding Quality

When you use the Therwen kit, you should notice reduced spatter and a clearer view of the arc area, which helps you weld more cleanly. The contact tips conduct current consistently, helping stabilize arc behavior and bead formation when flux core wire is in use.

Spatter Reduction and Visibility

The nozzle and tip geometry here is designed to minimize spatter compared to worn tips or mismatched nozzles, so you’ll spend less time cleaning and grinding after a weld. The open area and fit also give you a better line of sight to the puddle, which improves accuracy, especially on longer beads or when working in tight spots.

Heat Resistance and Durability

Brass and copper components are chosen for thermal conductivity and resistance; they tolerate prolonged cycles and repeated heating and cooling better than cheaper plated steel tips. That said, longevity still depends on your duty cycle, welding amperage, and how often you clean or replace parts; heavy industrial, continuous use will wear these faster than intermittent hobby or maintenance work.

Compatibility and Fitment

This kit is designed for flux core and gasless MIG setups and mentions compatibility with common MIG gun styles that use the KP1939-1 nozzle and similar contact tip threadings. Before you buy, you should compare the KP1939-1 reference and the product drawings to the parts on your gun to make sure thread sizes and nozzle shapes match.

How to Check Compatibility

Start by checking the reference model KP1939-1 and any model numbers your machine’s manual lists for replacement tips and nozzles. Also measure your existing contact tip diameter, thread style, and nozzle internal dimensions and compare them to the images and spec details provided with the kit to avoid mismatch.

Installation and Replacement

Replacing a contact tip or nozzle is straightforward and something you can do in minutes with a few basic tools; proper replacement decreases downtime and improves weld consistency. Tighten parts to a snug fit, but avoid over-torquing copper tips to prevent thread galling or deformation.

Step-by-step Replacement Guide

First, unplug power and ensure the gun is cool to the touch; safety first. Then remove the old nozzle by sliding it off and unscrewing the tip from the gas diffuser or tip holder. Clean the tip holder and threads with a soft brush, then screw in the new contact tip until it seats properly; reattach the gasless nozzle and confirm alignment so the wire feeds straight through. Finally, test feed the wire and make a short weld on scrap metal to confirm smooth feed and consistent arc.

Build Materials and Construction

The kit uses a mix of brass and copper—materials favored for their electrical and thermal properties in welding consumables. Brass and copper resist heat buildup and conduct current well, which helps maintain a steady arc and reduces localized overheating.

Why Brass and Copper Matter

Copper contact tips are excellent conductors that lower electrical resistance, helping maintain consistent arc characteristics and reducing amperage fluctuations. Brass nozzles balance strength and heat resistance, and both materials are more robust than inexpensive plated steel or zinc alloys that can degrade faster under heat.

Package Content and Portability

Because the kit includes 48 parts, you’ll probably find it useful as a spare set for a workshop or portable toolbox. The individual pieces are small and lightweight, so you can store them neatly in labeled compartments or a small organizer to keep sizes separated and accessible.

Storage and Organization Tips

Keep the 0.030″ and 0.035″ tips separated in small labeled bags or a compartment box so you don’t grab the wrong size in the middle of a job. Around the shop, a magnetic tray or foam insert in a drawer can prevent parts from getting lost and makes it easy to bring the right spares with you when you go to a job.

Pros and Cons

This kit gives you a lot of parts for a reasonable price point and is particularly useful if you switch between 0.030″ and 0.035″ flux core wire. The main limitation is that it’s a generic replacement kit—so while it fits many common guns that accept KP1939-1-style parts, it won’t be universal for every MIG gun without checking dimensions.

Advantages

You’ll appreciate the large quantity of consumables that reduce workshop downtime and let you swap worn parts quickly. The brass and copper construction makes the kit a better long-term value compared to cheap plated tips that wear out faster.

Limitations

If your gun uses a proprietary nozzle or a non-standard thread size, these pieces may not fit without an adapter or a different replacement set. Heavy industrial users running high-amperage, continuous cycles may still find consumable wear faster than the kit can replace, so you’ll need to compute how many kits you’ll go through.

Comparison with Similar Kits

Compared to other 3rd-party flux core tip and nozzle kits, the Therwen set is competitive on quantity and materials while being priced to appeal to hobbyists and small shops. Some premium OEM kits may offer tighter tolerances or brand-specific fitment, but those often cost more and may not include as many parts per set.

Price-to-Value Assessment

If you’re buying spare parts to keep a small shop running or to take to job sites, the price per piece here is attractive when you factor in the brass/copper materials and the sizeable counts. For professional operations with high consumable turnover, consider bulk OEM consumables if your machine manufacturer offers bulk pricing or longer-life options.

Tips for Best Results

Use the contact tip diameter that matches your wire size and adjust the welder’s voltage/current so the arc is stable without excessive burnback or spatter. Regularly clean the nozzle interior, remove slag buildup, and inspect tips for erosion or mushrooming that can affect arc shape and electrical contact.

Setting Up for Flux Core Welding

Set drive rolls and wire speed correctly to prevent birdnesting or feeding issues; wire slipping or grinding will shorten tip life and cause inconsistent arcs. If you notice frequent tip overheating, back off amperage slightly or check for poor contact between the tip and the contact tube—poor electrical contact increases heat at joints.

Maintenance and Care

To maximize the life of these parts, keep your gun clean, replace tips at the first sign of wear, and avoid dropping or mishandling copper tips which can deform or score easily. A simple routine inspection after each day of work will prevent many common performance issues.

Cleaning Tips

Use a small wire brush or a soft brass brush to remove spatter from the inside of the nozzle and the outside of the contact tip; avoid abrasive stainless brushes on copper to prevent grooves. For stubborn spatter, a little warm acetone on a rag can dissolve flux residues—make sure the parts are dry before reassembly.

Troubleshooting Common Issues

If you see erratic feeding, inconsistent arc, or excessive spatter, immediately check the contact tip for wear, check alignment of the nozzle, and verify the wire feed tension. Replace any contact tip that shows signs of burning, severe erosion, or a misshapen bore, as even minor deformities alter electrical contact and arc stability.

When to Replace Tips and Nozzles

Replace tips when you notice increased spatter, difficulty maintaining a steady arc, or when the tip’s bore is visibly enlarged or grooved. Nozzles should be replaced if they’re dented, internal surfaces are heavily built up with spatter that can’t be cleaned easily, or if the nozzle’s fit compromises wire alignment.

Safety Considerations

Always disconnect power and turn off the welder before changing consumables to prevent accidental wire feed or electrical contact. Wear appropriate gloves while handling hot parts and ensure the gun is cool before you disassemble components to avoid burns.

Personal Protective Equipment Recommendations

Use welding gloves, a welding helmet with the correct shade for flux core arc brightness, and safety glasses for grinding and cleaning tasks. A respirator may be advisable when welding materials or flux wires that produce significant fumes, and proper ventilation is essential in enclosed spaces.

Real-World Use Cases

If you’re doing repair work on farm equipment, automotive body framing, or light structural fabrication, the Therwen kit gives you the right mix of tip sizes and spare nozzles to handle most flux core applications. Home DIYers who switch between wire sizes will appreciate having both 0.030″ and 0.035″ options ready to go.

Ideal Projects and Applications

Use the 0.030″ tips for thinner sheet metal or finer-detail welding where control and reduced heat input matter. Reserve the 0.035″ contact tips for general-purpose flux core welding on thicker materials and structural tack welds where penetration and a robust bead are important.

How to Store Leftover Parts

Keep any unused tips and nozzles in original or labeled compartments; humidity and corrosive environments can subtly corrode components over long storage periods. A small desiccant packet in the storage case and storing in a cool, dry place will help preserve copper and brass components for longer.

Long-term Storage Best Practices

Wrap tips in paper towels or anti-tarnish paper if you plan to store them for months, and avoid keeping them in contact with steel filings or other reactive metals. For workshop storage, a hinged-molded plastic organizer with foam inserts helps you identify sizes quickly and prevents scratching.

Warranty and Support Considerations

Third-party consumable kits like this may not have the same warranty coverage as OEM parts, so check the seller’s return policy and any satisfaction guarantees before buying. If you have questions about fitment, contact the seller with your gun model and current part measurements to reduce the chance of getting incompatible pieces.

What to Ask the Seller

Ask for the exact thread specifications and internal nozzle dimensions if your gun uses an uncommon configuration. If you’re buying for multiple machines or for tools on different jobs, confirm the KP1939-1 reference against your machine manual or existing parts.

Frequently Asked Questions (FAQ)

Can you use these tips for both flux core and MIG with shielding gas? In many cases, 0.030″ and 0.035″ contact tips will work for both flux core and gas-shielded MIG, but ensure the nozzle and diffuser design suit the gas-shielded configuration if you switch modes. How long will tips last? Tip life depends on amperage, wire quality, duty cycle, and how often you clean spatter—light hobby use will stretch these much longer than heavy production work.

Quick Answers to Common Concerns

If your wire keeps jamming, check the tip bore, liner, and drive-roll settings before blaming the tip; many feed problems are liner- or feed-roll-related. If the arc is unstable after replacing a tip, double-check seating and electrical connection between the tip and the power transfer components of your gun.

Final Recommendation

If you want a practical, cost-effective supply of flux core contact tips and nozzles for occasional to moderate use, the Therwen 48-piece kit is a solid choice that balances quantity and material quality. Verify fitment with your welder model and existing parts before purchasing, then keep these spares organized so you can swap consumables quickly when needed.

Should You Buy It?

Buy the kit if you value having a large cache of replacement parts on hand and if your gun accepts KP1939-1 style nozzles and the common 0.030″/0.035″ contact tip sizes. If you run a high-hour production environment or need guaranteed OEM fitment and tolerances, consider OEM or bulk professional-grade consumables designed specifically for your welding system.

If you want, I can help you confirm fitment by guiding you through how to measure your existing nozzle and tip thread sizes, or I can summarize the top alternatives available if you tell me your welder model.

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