Most manufacturing operations are looking for ways to improve productivity and throughput to gain a competitive edge. Industrywide, a greater priority is being placed on making processes as efficient as possible. 

In the right welding applications — including those found in many heavy equipment manufacturing operations — a conversion to metal-cored wire can be a solution to deliver significant productivity and time-saving benefits. 

To reap the advantages that metal-cored wire can provide, consider some key factors and best practices. 

Solid wire or metal-cored wire? 
Traditionally, solid wire has been used for many of the welding applications common in heavy equipment manufacturing. 

Because of its historical use in the industry, many welders are familiar and comfortable with solid wire. It’s also seen as readily available and often considered a cost-effective option since it generally has a low cost per pound. 

However, with the increasing emphasis on improving productivity and efficiency in the industry, more operations are looking to metal-cored wire to save time in the welding process.

Advantages of metal-cored wire 
Metal-cored wire is formulated to provide specific benefits and properties, including reduced spatter during welding, a better bead profile and greater tolerance for dirty base material. Converting to metal-cored wire can provide benefits before, during and after welding — results that help save time and money. 

First, metal-cored wires offer significantly higher deposition rates per given heat input compared to solid wire in many applications. This can result in increased travel speeds and reduced distortion on critical components, meaning manufacturers moving to metal-cored wire often achieve faster throughput with less rework. 

Also, metal-cored wires tend to be more tolerant of dirt, mill scale and rust on the base material, so the base material doesn’t need to be as clean to produce high-quality welds. This saves time by eliminating or reducing non-value-added activities such as cleaning, grinding and preparing the material prior to welding. Metal-cored wire is also typically more tolerant of gaps; this provides more flexibility since part fit-up may be less critical than it is with solid wire. 

These advantages of metal-cored wire also help save time in the post-weld process. Because less spatter is typically produced with this type of wire, there is a reduced need for grinding and post-weld cleaning.  

Some specific types of metal-cored wires are formulated to provide easier removal of silicon deposits or silicon islands on the surface of the weld, which also saves time in post-weld cleanup and grinding. 

Time is money 
In the average semi-automatic welding operation, labor accounts for about 85 percent of the total costs. Any reduction in time spent on non-value-added activities helps make an operation more productive — and can have a substantial impact on the bottom line.

The ability to reduce or eliminate the time spent on certain tasks during the welding process — such as cleaning, applying anti-spatter, removing spatter and slag, and post-weld grinding — can provide significant productivity and efficiency benefits without adversely impacting the overall throughput or quality of the welding operation. 

Filler metal options
Carbon and low-alloy steels are among the commonly welded materials in heavy equipment manufacturing. Metal-cored wires are flexible and work well with many of the welding applications in this market. Most metal-cored wires are well-suited for welding medium- to heavy-gauge plate and for lap welds, fillet welds, T-joints and groove welds, for example. 

Common diameters of metal-cored wires are .045-, .052- and 1/16-inch. Often, switching from a solid wire to a metal-cored wire allows for an increase in wire diameter, such as from a .045-inch solid wire to a .052-inch metal-cored wire, while using similar welding parameters. Because the heat input is typically lower with metal-cored, the process can handle a larger wire diameter and provide higher deposition rates. A larger-diameter wire often means more material going into the weld joint, improving productivity to help get the job done faster. 

For welding carbon steels, a common filler metal choice is American Welding Society (AWS) E70C-6M, a mild-steel metal-cored wire. For higher-strength materials, there are many low-alloy metal-cored wires available to match the base material properties. With T1 steels, a good choice may be an AWS E110C-K4, a high-performance filler metal that offers 110,000 psi tensile strength. 

There are many options, and the right filler metal choice depends on the material being welded and the needs of the specific application.

Proper technique 
The techniques for welding with metal-cored wire are comparable to the proper techniques for using solid wire. Torch angles and contact-tip-to-work distances are similar with both types of filler metals. This allows welders to learn metal-cored welding with minimal training. 

Metal-cored wire does provide more tolerance and a wider operating range than solid wire, so welders often find it easy to create high-quality welds. The penetration profile of metal-cored wire tends to be wider and provides a bit more flexibility compared to solid wire. From an operator standpoint, this means torch placement may not be as critical to achieving success with metal-cored wire. 

Other factors to consider
When considering a switch from solid wire to metal-cored wire, there are a few other factors to keep in mind to determine if it’s the right choice for a specific heavy equipment manufacturing application.

Metal-cored wires provide optimal results and productivity gains in longer, continuous welds that are in position. These wires are generally not as productive for applications involving many short welds with a lot of stopping and starting. 

Like solid wire, metal-cored wires typically aren’t the most productive for applications that involve vertical and overhead welding. However, they can often be used for out-of-position welding with either a short-circuit transfer mode or a pulsed process. 

A productive change 
A lack of experience with metal-cored wires may lead to uncertainty in some operations about making the switch. But these filler metals are designed to offer ease of use, high deposition rates and a good bead profile with reduced spatter. 

In welding applications that are well-suited for conversion, metal-cored wires can help significantly improve productivity and save time and money in the operation — while maintaining the high weld quality necessary in heavy equipment manufacturing.

Consult a local welding distributor or the filler metal manufacturer for answers to specific questions and help in determining if conversion to metal-cored wire is right for the application.