01Jun 2018
How Tube and Hollow Bar Differ

Hollow metal tubes and bar are used for various structural applications. Metal tubes and hollow bar are cheaper and weigh less than a solid metal bar, while still providing the strength of a solid metal bar. Though they look similar, the two have a variety of differences. In this article, we will see the main differences between tube and hollow bar.

Manufacturing Process

Tubing is formed by running slit coils of metal through a tube mill to create a round, rectangular, or square tubular shape. The edges are then welded together using a process such as electric resistance welding or high-frequency welding. The method used depends on the type and thickness of the metal, as well as the preferences of the manufacturers. The tube is then refined with an annealing process to create the final product.

Hollow bar is not welded together. Instead, hollow bar is created using one of two processes. The first, called drilling, involves sending a drill through a solid bar stock. The second, called centrifugal casting, is when molten metal is poured into a cast as it undergoes high-speed rotation. The high-speed rotation forces the metal to the outside of the frame, where it hardens as it cools to create a dense, uniform final product. Hollow bar typically only come in bronze and stainless steel.


The difference in manufacturing makes for a big difference in quality. Hollow bar can be created to be flexible and fit into tight dimensions in a way that tube can’t. Tubing can also result in a lower quality product when the manufacturer is unskilled.

Avoid a reduction in quality by removing the excess weld metal and heat-treating, or annealing, the tube after welding. Otherwise, crystalline structures may affect the strength and structure of the metal that develop.


Most materials can be formed into tube using the welding process. This process is appropriate for any material that conducts electricity. While hollow bars can also be made out of most materials, it can be challenging to extrude strong and hard materials.

The choice between hollow bar or tube is ultimately up to you. Take into consideration what type of project you’re doing, your desired material, budget, and your project’s final application.

Regardless of what you choose, be sure that your materials and compounds are of the highest quality by choosing Avion Alloys. We procure prime metals exclusively from United States Mills, and we are a NASA approved vendor. For a free quote, contact us at (866) 610-1660.

08May 2018
HSLA Steel

High-strength low-alloy (HSLA) steel is made from carbon combined with trace alloying elements that increase its strength. This type of steel has a higher level of toughness and responds better to heat treatment than other types of steel. HSLA steel has an increased ability to resist corrosion.

The Manufacturing Process

HSLA steel is produced by mixing coal and iron ore in a furnace hot enough to melt these elements. Adding the alloying materials to the molten mixture in varying amounts will result in different grades of HSLA steel. The steel is purified and then solidifies in a rectangular shape.

Advantages of HSLA Steel

HSLA has several benefits compared to traditional carbon steel. The atoms in the alloying elements increase the hardness and strength of the steel by blocking movement in its microstructure.

These elements can include:

  • Vanadium
  • Nickel
  • Tungsten
  • Silicon
  • Manganese
  • Molybdenum

Other elements are effective in increasing the steel’s resistance to corrosion. Chromium, copper, and nickel help prevent the formation of rust as well.

Grades of HSLA Steel

HSLA steel can be manufactured in many grades and used for diverse applications because of the range of alloying elements that can be added in different amounts. One common type is ASTM A36, which is general purpose HSLA steel primarily used for erecting structures. It’s popular because it is machinable, weldable, and affordable, with versatile mechanical uses.

Weathering steel is most often used in applications such as bridge construction where it will not be painted or coated. ASTM A242 and ASTM A588 are two frequently used types of weathering steel.

Oil and gas transmission pipelines often use HSLA steel. Many modern pipelines rely on API 5L Grade X70, with the number 70 referring to the minimum yield strength of 70,000 pounds per square inch. ASTM A573 is popular for petroleum storage tank construction.

Many other grades of HSLA are available for a range of engineering purposes, including steel that is easily weldable, resists abrasion, or is hardened by precipitation. The engineering project manager is charged with choosing the right type of steel for the specific job.

High-strength low-alloy steel is used in a variety of different fields for various items. If you’re in need of HSLA steel, look no further than Avion Alloys. As a NASA-approved vendor, we produce high quality materials for multiple industries. Contact us today for a free quote.

23Feb 2018
Several Sharp Chef Knives Laid Out On Wood

A good knife can be an incredible tool. It can help you create a great meal, and it can help you cut branches to make a fire. Knives are used constantly in kitchens, and a high-quality knife can be a priceless tool for use on camping and hiking expeditions. Because of the importance of knives in a variety of industries, the quality and composition of knives are critical to its reliability. Continue reading

09Feb 2018
Glowing Carbon Steel

Carbon Steel is a metal used in many different industries, as it is affordable and has a wide range of properties that can be used in a variety of mechanical applications. This type of steel is 0.5 percent to 2.0 percent carbon with iron and trace levels of other metals in its composition. It’s important to choose the appropriate carbon steel grade for the needs of the project at hand. Here are some questions to consider when choosing a type of carbon steel. Continue reading