Aluminum seamless tubing is used in every military aircraft, like the C-130, F-35, and F-16, to increase reliability. Also, because aluminum is a lightweight, corrosion-resistant material, seamless tubing is used in commercial aircraft as well. Welding is not always an option for aerospace tubing because of the vulnerability that a seam poses.
“The seam would be the weakest part of the tubing so aluminum seamless tubing is used more in aerospace, especially by defense contractors. They don’t want any weak spots at all in the application,” said Jamie Barron, Vice President of New Source Corporation.
Formed in one of two ways, either by pushing a hollow aluminum billet through a mandrel press and dye at a high temperature or pushing a solid billet through a piercer press and extruding the billet with a mandrel, seamless tubing has several advantages. In addition to avoiding the weakness that a seam could present, seamless aluminum tubing has good oxidation and corrosion resistance and mechanical properties that make it suitable for many uses.
Uses and shapes for aluminum seamless tubing
Aerospace manufacturers typically use seamless aluminum tubing for the fuselage in an aircraft. “Whether it’s for holding wire or the actual building blocks of the plane itself, it is mostly used on the inside of the plane,” Barron said. It’s used for fuel lines as well.
Seamless tubing made from 6061 aluminum is particularly common. Its uses range from small appliances to HVAC and hydraulic systems.
Tubing can also be extruded. Structural tubing is mass-produced in shapes like rectangles and squares, for example. New Source Corporation’s supply of seamless tubing includes hard-to-come-by parts like BAC 1501 tubes, which are popular for their unique shapes and multiple purposes.
Seamless tubing sizes and thicknesses
Tubing varies in size and thickness in addition to shape and purpose. The size is a tube’s diameter as measured in inches and the thickness indicates the depth of the wall within the tube, which is also measured in inches.
A common tube is 6061 Aluminum T-4 temper that is 1” in diameter and has an 11/32” (0.35”) wall. A 12” long tube of that type weighs 1.5 pounds.
The weight of a tube is important because it affects the minimum amount of tubing a customer must buy. Suppliers typically set a minimum number of pieces because individual tubes can be small and many of them are needed to cover the costs of purchasing the raw material.
For example, if a buyer needs 6061 Aluminum-T4 temper tubes that weigh 1.5 pounds each, they may have to get 67 pieces, even if they only need two or three. They may also have to wait 20 weeks for those pieces to be produced and delivered unless they use a supplier that already stocks the tubing.
“Rather than our customers buying the minimum and having to wait, we have already made the investment and have the inventory on hand,” Barron said. “As a true stocking distributor, there is no minimum buy requirement for our customers.”
New Source Corporation maintains a large supply of seamless tubing, ranging from 3/16” (0.188”) in diameter to 5” in diameter so that it can fill even smaller orders and deliver them quickly. It also offers vendor-managed inventory and just-in-time delivery.