K227-1 - Lincoln Electric LT-7 Submerged Arc Tractor Feeder

Precision Mechanized Submerged Arc Welding

The Lincoln Electric LT-7 Tractor (Standard Model) is a self-propelled, mechanized wire feeder engineered to deliver consistent, high-quality welds in submerged arc (SAW) applications. Designed for heavy industrial environments, this unit combines portability with robust performance, making it an essential tool for ship building, bridge deck installation, and storage tank erection. The K227-1 model operates on 115 VAC input power and integrates seamlessly with a variety of Lincoln Electric DC constant voltage and constant current power sources. By automating the travel and feed process, the LT-7 ensures uniform bead appearance and deep penetration on heavy plate applications.

Advanced Drive and Control System

At the core of the LT-7 is a calibrated tractor drive system that offers precise control over travel speeds ranging from 6 to 70 inches per minute (0.12 to 1.8 m/min). This wide range allows operators to fine-tune heat input and deposition rates for various material thicknesses, from light 12-gauge steel to heavy structural plates. The wire feed mechanism is equally robust, capable of feeding solid wires ranging from 3/32 inch to 3/16 inch (2.4 to 4.8 mm) at speeds between 100 and 400 inches per minute. The control box is ergonomically mounted on the tractor and can be positioned on either the left or right side, eliminating the need for the operator to return to the power source to make routine procedure adjustments.

Versatile Configuration and Alignment

The LT-7 Tractor is designed for versatility in joint configuration. It features a vertical head lift adjuster that allows for electrical stick-out adjustments from 1/2 inch to 5 inches (12.7 to 127.0 mm), accommodating different flux depths and welding procedures. The welding head can be angled up to 50 degrees from vertical on either side and supports a drag angle of up to 30 degrees. This flexibility enables the unit to perform butt welds, horizontal fillet welds, and lap joints with ease. The tractor's exceptional tracking control and self-steering capabilities ensure close mechanical alignment between the wire and the joint, maximizing weld quality while minimizing the need for expensive fixturing.

Rugged Industrial Design

Despite its heavy-duty capabilities, the LT-7 is surprisingly compact and lightweight. Weighing in at 120 lbs (54.4 kg) and measuring just 14 inches in length, it can be easily moved to the next joint or passed through small openings in confined spaces. The unit is rated for 600 amps at 100% duty cycle, with a maximum rating of 1100 amps, ensuring it can handle the rigorous demands of continuous industrial welding. The K227-1 package includes a 25-foot control cable (K1822-25), providing ample reach for large-scale fabrication projects.