Is It Legal to Weld a Truck Frame? – Vehicular Safety Guide

This guide will take you through the legalities of welding a truck frame and answer the most frequently asked questions.
Christopher McDonagh
Christopher McDonagh
Research Writer
Chris is a teacher of Literature at a school in New Berlin, Wisconsin. He is also our favorite irreplaceable freelance writer who can turn such a boring topic into something read more
Reviewed By
Thomas Garcia
Thomas Garcia
Expert Consultant
Thomas is a professional welder who gained his certification several decades ago and learned all the nuances of this job since then. When not at work, Thomas loves fishing i read more
Last updated: August 13, 2023
Weld Zone is reader-supported. We may earn a commission through products purchased using links on this page. Learn more about our process here

Is it legal to weld a truck frame? Well, this welding car frames a gray area because federal law hasn’t explicitly made it illegal. There are, however, requirements on how it should be done.

As a welder, there are instances where you may consider welding the chassis. The thought may even be exciting. However, you may be getting yourself into murky eagle waters. In this guide, we’ll highlight everything you need to know about welding a truck frame including whether it’s legal or not. We’ll also take you through the FMCSA vehicular safety rules and a patched frame inspection. Let’s dive right in!

Is It Illegal to Weld a Car Frame?

Welding technology has advanced greatly and according to the NCBI, in the past, people welded metal by hammering and hitting overlapping pieces. Now, there are powerful welders available. According to most reviews, the Weldpro 200 Amp Inverter Multi Process Welder is the best option. It comes with a 3-year warranty and goes beyond flux core and MIG welding. This welder also comes with a digital display that makes it easy for you to set wire speed and amperage for unbeatable welds.

You can weld truck frames legally in most states but you have to do it according to the manufacturer’s recommendations. Technically, you can solder all types of vehicles except those that carry passengers. However, you should note that welding commercial vehicles is a bad idea. This is because when you solder the chassis, its structural integrity becomes weak. You also can’t take your commercial truck out on the road if you weld the frame.

Is It Legal to Weld a Truck Frame? - Vehicular Safety GuideIf you’re looking to sell your truck, you’re required to disclose to the buyer if the frame is damaged, broken, bent, or welded. Technically, the law does not prohibit you from selling a welded truck or a vehicle whose frame has been modified. It’s only illegal if you sell it without informing the buyer of these modifications.

If you really have to weld your truck’s frame, you should ensure that you’re well within the manufacturer’s recommendations. This is especially true if your vehicle is a commercial truck or has a semi-truck frame. You should also pay close attention to the car’s roadway safety because truck frame modifications, repairing a damaged frame, and welding the metal components can compromise the truck’s integrity.

Finally, make sure your repairs are also within the legal parameters and manufacturer’s recommendations.

It’s important that you use the correct safety gear during the welding process. For starters, you should have an industrial welding helmet, and based on multiple reviews, the Viking Industrial Passive Black Welding Helmet is a great option. It’s fairly affordable and comes with a sleek design with an amazing matte finish. This helmet also has a decal sheet that allows you to customize it to your preferences.

You should note that even though welding a truck frame is not illegal, it’s very dangerous. This is because your truck’s frame is technically a skeleton that holds all the parts together. When you weld it, it makes the frame weak, which creates a safety hazard. For instance, if the truck gets into an accident, the welded area may break, posing a great safety risk.

While welding a truck frame is legal, drilling holes in commercial vehicles is prohibited, there is one exception; if the manufacturer recommends it in their guidelines, then you can.

FMCSA Vehicular Safety Rules

The FMCSA (Federal Motor Carrier Safety Administration) is the government body that’s in charge of setting rules and regulations concerning vehicular safety. In this section, we’ll take you through the summary of their safety standards.

  • The chassis or frames of commercial vehicles shouldn’t be broken, sagging, loose, or cracked.
  • You should ensure that the brackets or bolts that are securing the body or cab of the vehicle to the chassis aren’t missing, broken, or loose.
  • You should ensure that the rail flanges are not notched, cut, or bent not unless this is one of the manufacturer’s specifications.
  • You shouldn’t drill holes in the bottom or top of the rail flanges except when the manufacturer recommends it.
  • You shouldn’t weld the parts and accessories of a chassis or frame of a commercial vehicle not unless this is in accordance with the recommendations from the manufacturer. If you also decide to make any welded repairs to the vehicle’s frame, they should be as recommended by the manufacturer.

You should note that the FMCSA rules are federal regulations. So, if you fail to follow them, you risk having your vehicle seized. In addition, if you weld your passenger-carrying vehicle you may incur hefty fines which if left unpaid can result in harsher consequences.

Patched Frame Inspection

According to Research Gate, the main causes of deformed and damaged car body frames include using the wrong type of welding materials and joining technology. During a patched frame inspection, the inspectors examine the bonds and connections between the metal components to ensure their integrity is intact. They use both electrical instruments and visual tools to check the safety and quality of the connections. Your truck’s frame could pass the inspection if the welding was done by a professional.

Here’s what various states look for:

  • Pennsylvania: how permanent the patched frame is.
  • Texas: whether you followed the manufacturer’s guidelines.
  • Vermont: whether the repairs, welds, and patches meet the manufacturer’s requirements.
  • New Zealand: whether the chassis repair follows the material specifications, manufacturer’s recommendations, and are compatible with the material specifications.

State Laws on Welding Truck Frames

These laws vary, but the most common ones include:

  • The Land Transport Rule: if fitting an A-frame will significantly affect the frontal impact protection feature’s performance, then you shouldn’t do it.
  • You need vehicle specialist certification to make heavy chassis repairs.
  • All the welding should be done by a qualified welder.
  • Texas doesn’t have any restrictions on welding frames as long as it’s correctly done.

You also shouldn’t operate a commercial truck with a welded frame on public roads.


Is It Legal to Weld a Truck Frame in P.A.?

Yes, but you have to abide by the strict inspection requirements. For instance, all structural repairs should be permanent and free of tar paper and tape.

Is It Legal to Weld a Truck Frame in N.Y.?

Yes, your truck’s frame will pass a patched frame inspection if the welding was done professionally and there are no hanging items or cracks on the frame.

Is It Legal to Weld a Truck Frame in Ontario?

No, as long as you adhere to the manufacturer’s recommendations. It’s, however, illegal to weld the frame of a passenger-carrying vehicle.

What is Cut and Shut?

Cuts and shuts are vehicles formed by welding 2 vehicles, mostly those involved in a collision, together. The cars used usually have one end that wasn’t fully impacted in the collision, and the welders use these halves to weld the 2 cars. You should however note that this is highly risky even when done by a professional welder. This is because the resulting car lacks sufficient force resistance that comes in handy during high-speed collisions. The car tends to fall apart easily resulting in fatal injuries. If you’re purchasing a car and suspect that it’s cut and shut, pay close attention to the VN pints. If you notice that they don’t match up then you should ask further questions.

What Are the Best Methods for Welding Car Frames?

There are 2 main methods you can use to weld your truck frame; Metal inert gas (MIG) and tungsten inert gas (TIG). The TIG method bonds 2 metals together using rods, so it’s not recommended for welding trucks because it’s mostly suitable for thinner rods.  MIG method, on the other hand, is better for thicker rods and is easier to use. This is because it bonds two metals together using a filler material. One of the other reasons why the MIG method is mostly preferred is that it’s very forgiving and makes it easy for you to correct minor mistakes.

If you’re in the market for the top MIG welders, we have compiled a review of the 9 best MIG welders in the market to help you make an informed purchase decision. We also have comprehensive guides for the best MIG welders under $1,000 and the best multi-process welders under $1,000.

Final Thoughts

Is it legal to weld a truck frame? Technically it is, but you have to adhere to the manufacturer’s recommendations. This is the only way your truck will pass a patched frame inspection. We also recommend that you use the MIG welding method as it works best with thick metal frames. It also allows you to correct the mistakes you make. You should, however, note that while welding a truck’s frame is legal, you aren’t allowed to drive such a truck on public roads. This is because the welding impacts the frame’s structural integrity, resulting in fatal injuries in the event of a collision.

Leave a comment

Your email address will not be published. Required fields are marked *