Weldment Design for Industrial Products

Proper weldment design can dramatically reduce costs, weight, and lead times for your industrial products. Here's what you need to know to get the most out of welded assemblies.

Marcus Riganelli, P.Eng.

Principal Engineer

Welder fabricating a steel weldment assembly with sparks flying in a shop environment

If you’ve ever received a welded product that cost more than expected, arrived late, or needed rework before it was usable — the root cause was likely a design issue, not a manufacturing one. Weldment design is one of those areas where a little expertise up front prevents a lot of pain down the road.

A weldment is an assembly created by welding together commonly available metal products such as sheet metal, plate, tube, and structural sections. Compared to casting or machining, weldments are often more cost-effective, with fewer restrictions on size and quantity. When designed correctly, they deliver strong, lightweight, and economical results. When designed poorly, they can drive up costs without adding any real benefit.

You know your product and your market better than anyone. We bring the engineering knowledge to translate that into a weldment design that performs, manufactures efficiently, and keeps costs under control. Together, we can develop a strategy that takes full advantage of what welded assemblies have to offer.

Laser cutting a steel plate for weldment components

Why Use Weldments?

Whether you’re developing a new piece of industrial equipment, redesigning an existing product to reduce costs, or launching a proprietary product line for the first time, weldments can be an excellent way to reduce overall cost and complexity. They’re particularly effective at minimizing weight while maintaining the strength and functionality your application demands — and they’re faster and cheaper to manufacture because they require no specialized tooling.

Key benefits include:

Strength and rigidity — Welded frames withstand impact loading and maintain alignment under demanding conditions.
Design flexibility — A wide range of standard metal products can be combined to meet nearly any requirement.
Watertight and airtight construction — Ideal for enclosures, tanks, and sealed assemblies.
Low overhead — No tooling investment or tooling lead time. Custom jigs can be introduced later for high-volume production.
Minimal finishing — Weldments can be painted shortly after welding and cooling, with little to no cleanup required.
Reduced machining — Post-weld machining costs can be minimized by combining parts and setups.
Fast turnaround — Low per-piece cost and short lead times keep your project on schedule.

Manufacturing a precision machined component on a CNC lathe

Designing Effective Weldments

Weldment design is a multi-step process that requires an understanding of the application, materials, welding technology, and joint design. Here’s a breakdown of the key considerations.

Planning

As with any design effort, it’s important to define the purpose of the weldment before diving into the details. Where does it fit within the larger product? What are the performance requirements, budget constraints, and production timelines? Answering these questions early helps us produce an efficient design and reduces the risk of over-engineering.

Material Selection

Weldments are typically made from steel or aluminum, each with distinct advantages:

Steel — Incredibly versatile, with a wide range of alloys available for almost any application. Mild steel is easily weldable, affordable, and available in many shapes and thicknesses. Certain alloy steels can produce high-strength, impact-resistant joints that are often stronger than the base metal itself.
Aluminum — Valued for its excellent strength-to-weight ratio and formability. Custom extrusions add further flexibility, and there are additional finishing options for cosmetic parts. However, aluminum weldments are more expensive, the joints tend to be weaker than the base material, and the welding process itself can be more challenging.

Joint Design

Joints should be optimized to use the minimum amount of weld material while still achieving the required strength. Choosing the wrong joint type can significantly increase welding costs or compromise the product’s function.

Equally important is designing joints that are easy to weld. Overcomplicated assemblies with complex joints make it difficult for welders to achieve consistent, high-quality results.

Welding Process Selection

The choice of welding process has a direct impact on cost and quality:

TIG welding produces a clean, precise weld but is slower.
MIG welding is faster and well-suited to many production applications.
Automatic processes like SAW (submerged arc welding) are both fast and produce high-quality welds with excellent penetration.

Selecting the right process for your application is an important part of keeping costs under control.

Avoiding Overwelding

Overwelding — specifying continuous welds where intermittent welds would suffice, or oversized throat dimensions — is one of the most common and costly mistakes in weldment design. The consequences include:

Distortion — Excessive heat can warp the part. Materials like stainless steel are especially prone to thermal distortion. This can be managed by reducing weld size and length, using intermittent welds, and alternating the welding sequence.
Increased cost — Unnecessary welds add material, labour, and potentially testing costs. Welds should only be placed where they’re needed to achieve the required joint strength.

Welding Procedures

A well-defined welding procedure ensures consistent results while meeting code requirements. The designer and fabrication shop should collaborate on the process before production begins. A few ways to reduce costs through procedure optimization:

Weld position — Downward welding is the most economical. Overhead and vertical welds require more experienced welders and additional precautions.
Preheat management — Specifying the correct filler material, weld process, or base material can reduce or eliminate costly preheating steps.
Welding speed — Where distortion isn’t a concern and appearance isn’t critical, increasing welding speed reduces time without sacrificing joint strength.

Professional manufacturing drawings with caliper for quality inspection

Let’s Work Together

The proper use of weldments in product design can significantly reduce overall costs, lead times, and part complexity. Many of our clients come to us after experiencing the frustration of poorly designed weldments — products that cost too much, took too long, or didn’t perform as expected. With the right design approach, those problems are avoidable.

When you work with us, you stay in control of your product. We combine your industry knowledge with our engineering expertise to develop a weldment design that’s optimized for your application, your budget, and your manufacturing timeline. The result is a product you own completely — with professional drawings, manufacturing files, and the confidence that it’s been designed right.

If you’re developing a product that involves welded assemblies, reach out to Riganelli Engineering. We’ll help you understand your options and build a design plan that sets your product up for success.