The Lincoln LN-25 PRO / Magnum PRO Curve 300 One-Pak (K4101-1) bundles Lincoln's rugged portable industrial wire feeder with a Magnum PRO Curve 300 welding gun and a cored wire drive roll kit for .040–.045 in. wire — giving ironworkers, pipefitters, and fabricators everything they need in a single purchase to run FCAW or GMAW on any CV power source delivering 15–110 V DC.
| Specification | Detail |
|---|---|
| Model | LN-25 PRO / Magnum PRO Curve 300 One-Pak |
| Part Number | K4101-1 |
| Spool Capacity | Up to 45 lb (20.4 kg), 12 in. (305 mm) diameter |
| Wire Diameter Range | Drive roll kit included: .040–.045 in. (1.0–1.2 mm) cored wire; feeder accepts solid steel .023–1/16 in. and cored up to 3/32 in. with alternate rolls |
| Voltage Source | Across-the-arc CV power source; 15–110 V DC at studs (no control cable required) |
| Drive Roll Type | 2-roll Maxtrac™ cast aluminum drive; Cored Wire Drive Roll Kit (.040–.045 in.) included |
| Compatible Welder Series | Lincoln Flextec, Ranger Engine Drive, Vantage Engine Drive, CV Family, Idealarc Family |
| Cable / Reach | Max FCAW gun: 15 ft; max GMAW gun: 25 ft; Magnum PRO Curve 300 gun included in kit |
| Duty Cycle | 450 A / 60%; 325 A / 100% |
| Welding Processes | MIG (GMAW), Flux-Cored Gas-Shielded (FCAW-G), Flux-Cored Self-Shielded (FCAW-S) |
| Kit Includes | LN-25 PRO wire feeder, Magnum PRO Curve 300 Welding Gun Ready-Pak, Cored Wire Drive Roll Kit (.040–.045 in.) |
| Weight | 37 lb (16 kg) feeder |
The K4101-1 One-Pak is designed for professionals who want to start running flux-cored wire immediately without sourcing the feeder, gun, and drive rolls separately. The included Magnum PRO Curve 300 gun is Lincoln's heavy-duty ergonomic gun with a curved handle to reduce fatigue on long welds.
- Flux-cored structural welding: The .040–.045 in. cored wire drive roll kit is configured out of the box for the most common FCAW wire sizes used in structural steel erection — no drive roll swaps needed to start welding.
- Construction site and field erection: The across-the-arc feeder design eliminates a control cable, letting ironworkers move freely on elevated structures. The replaceable, flame-resistant case withstands jobsite abuse.
- Pipeline and heavy fabrication: The 45 lb spool capacity and 450 A / 60% duty cycle sustain high deposition rates for fill and cap passes on heavy-wall pipe or structural members.
- Shipbuilding and heavy equipment repair: The combination of a portable suitcase feeder and the ergonomic curved gun reduces fatigue during long overhead and out-of-position welds.
The LN-25 PRO in this One-Pak operates using across-the-arc power — it draws its operating voltage from the welding arc itself. Any machine delivering 15–110 V DC at the output studs drives this feeder without a control cable. Compatible Lincoln power source families include:
- Flextec Family — multi-process CV/CC machines suited for fabrication shops and field use.
- Ranger Engine Drive Welders — portable gasoline or diesel engine drives for remote sites.
- Vantage Engine Driven Welders — heavy-duty engine drives for pipeline and large-structure work.
- CV Family / Idealarc Family — Lincoln's constant-voltage transformer-rectifier machines found in shops and light-to-heavy industrial environments.
The feeder is also compatible with compliant third-party CV power sources in the 15–110 V DC range. See our full range of wire feed welders and CV power sources for compatible machines available at WeldingMart.
WeldingMart is an authorized Lincoln Electric distributor. Every Lincoln One-Pak we sell — including the K4101-1 — ships with its full manufacturer warranty intact through an authorized supply chain.
- Everything in one box: The K4101-1 One-Pak ships as a complete, ready-to-weld bundle — feeder, gun, and drive rolls — eliminating the risk of ordering mismatched components separately.
- Fast U.S. shipping: We ship from U.S. warehouse locations and offer expedited freight for large equipment packages.
- Expert support: Our welding specialists can confirm compatibility with your power source and recommend any additional accessories before your order ships.
- Authorized service access: WeldingMart's Lincoln authorized status gives you access to Lincoln's factory-trained service and parts network for warranty and post-sale support.