About Us

Lock Joint Tube manufactures mechanical and structural grade steel tubing in five plants located in Indiana, Ohio, Texas, and Tennessee. Selecting hot rolled, cold rolled, aluminized, and galvanized steel, Lock Joint Tube services fabricators and distributors, as well as original equipment manufacturers with different sized and shaped steel tubing used in such diverse industries as solar, automotive, office furniture, health care, exercise, and display fixtures to name a few.

Contact Us

Processing capabilities:

Processing capabilities: Mechanical and structural grade steel tubing, saw and laser-cutting, custom tubing sizes including round, square, rectangle, oval, octagon, and other various special shapes.

We excel in special-shaped tubing to help differentiate our customers in their particular marketplaces. Our In-house metallurgical lab hosts 2 degreed metallurgists and 60 years of expertise in product and process metallurgy.

Industries Served

Lock Joint Tube is proud to work with a variety of industries, including but not limited to:

Automotive
Heavy-duty truck
Solar
Recreational Vehicles
Furniture (office, hospital, music, standing desks)
Exercise equipment
Trailer

Why Lock Joint Tube?

We excel in special-shaped tubing to help differentiate our customers in their particular marketplaces. Our In-house metallurgical lab hosts 2 degreed metallurgists and 60 years of expertise in product and process metallurgy.

Our Metallurgists

Our metallurgists understand the importance of the raw material (steel coil) and how it responds to LJT processing into tubing. Design and engineering begins with technical interaction with the steel mills and optimizing chemistry, Hot Strip mill rolling practices, etc

Strive to reduce variability in our products so customer fabrications are predictable and controllable. This begins with consistency in raw materials, defining internal specifications often times more restrictive than industry or customer standards.

Apply best practice and Continuous Improvement methodologies to gain competitive advantages

Provide customers opportunities for cost reduction or light-weighting by introducing new shape profiles or stronger materials to reduce wall thickness or reduce tubing perimeter. LJT Technical Services offer customer Failure Analyses and Value Add Value Engineering support.

Lock Joint Tube is proud to work with a wide variety of industries including but not limited to:

Automotive, heavy-duty truck, solar, recreational vehicles, furniture (office, hospital, music, standing desks), exercise equipment, trailer.

we can accommodate special & unique requirements

Custom Tubing Solutions for Your Application

Request a Custom Quote Today

Process Innovation

At Lock Joint Tube, innovation isn’t just a buzzword—it’s in our DNA. For over a century, we’ve been redefining what’s possible in tube manufacturing. With over 360 unique shapes and sizes, we lead the industry in variety, offering more options than any other mill in North America.

Our commitment to precision and quality sets us apart. Our tube welds are held to half the industry standard, ensuring exceptionally tight tolerances. And with our latest investment in cutting-edge saw technology, we now deliver the smoothest tube end cut in the industry—because every detail matters.

Experience the difference with Lock Joint Tube.

Customer Service

At Lock Joint Tube, we understand that strong supplier communication is the foundation of a successful partnership.

It’s not just about responsiveness—it’s about proactive engagement and having knowledgeable experts readily available to handle inquiries, order adjustments, and job requests.

Your needs matter. For one customer, maintaining a precise outer diameter tolerance is critical. Another may need to adjust delivery dates due to shifting production schedules. Yet another requires detailed documentation on a tube’s heat number. Every customer has unique priorities, and we recognize, respect, and adapt to those needs with efficiency and expertise.

Engineering Expertise

At Lock Joint Tube, our engineering team is with you every step of the way.

Our process engineers help refine and lightweight designs, optimizing performance while reducing costs. Need testing? Our in-house laboratory offers salt spray tests and metallographic evaluations, using both macroscopic and microscopic analysis to ensure quality and durability.

Expert guidance, advanced testing, and cost-saving solutions—all under one roof. Let’s build better together.

Industries

We are committed providing excellent service to the automotive, construction, excersice equipment, fence, furniture and solar industries, and we are always expanding our capabilities. Have an idea for a project? Contact our engineers today!