How to Choose Stainless Steel Tubing Grades and Types


Many factors are taken into consideration in determining what grade of stainless steel tubing to select. The key requirement for stainless steels is that, for a given application or setting, they should be corrosion resistant. Power and fabrication features are also taken into account. More than 60 grades of stainless steel exist. The entire group can, however, be split into four metallurgical groups.

Additional mechanical or physical properties may also need to be considered to meet the overall service efficiency criteria when deciding what grade to choose.

Stainless steel is a widely used material because of its high corrosion resistance, hygiene, and strength in applications ranging from medical instruments or chemical storage to transport or power generation. Although there are more than 3,500 steel grades, not all grades are equally made.

With so many choices, how do you make sure that you choose the right grade for your particular needs?

Choose the Right Metal for Your Operating Environment

Think about the conditions your final product will face in order to decide which grade of steel will better perform in a given setting. Highly low pH, high stress and high temperatures, and crevice corrosion have a negative effect on the performance of stainless steel.

Steels in the austenitic T3XX series maintain their strength, durability, and corrosion-resistant properties over the broadest temperature range, like the common types Stainless Steel 347 Tubes and Stainless Steel 347H Tubes.

The primary trigger for selecting austenitic stainless grades is corrosion resistance. Stainless Steel 347 tubes also resists chloride ions found in marine applications with its molybdenum addition. With any grade of steel, the best defense against corrosion is high quality structural design.

Prioritization of Ductility, strength and toughness

First, consider these top three mechanical attributes:

  • Ductility: The ability of a material to shift its shape without losing strength or cracking, such as being drawn out into a wire or thread.
  • Strength: Until it cracks or deforms, the stress a metal can withstand.
  • Toughness: The strength of the metal to bend and absorb energy before fracturing.

Stainless steel, as its alloying element, contains 10-30 percent chromium, which is what helps it resist corrosion. Among stainless grades, the nickel addition in austenitic grades offers the highest strength and ductility. The most resistant to corrosion are grades high in chromium, molybdenum, and nickel.

The Stainless Steel 347 Tubes are essentially non-magnetic and have good toughness and strength.

Factor in Form and Process

In bar, wire, tube, pipe, sheet, and plate forms, austenitic stainless steel is readily available; most items need more shaping or machining before they can be used for their particular application.

For example, stainless steel tubing can involve bending or coiling, re-drawing, machining, welding, or end shaping. Choose a lower carbon grade like Stainless Steel 347L Tubes to reduce carbide formation.

Manage Material Cost and Availability

While the most costly stainless steels up front are high-performing austenitic stainless steels, they are well worth the investment. Maintenance, downtime, and replacement costs are reduced by choosing a corrosion-resistant material well-suited to its application. Life-cycle costing approaches will measure current and potential costs and establish a comparison of various materials with “apples-to-apples.” These Stainless Steel 347 & Stainless Steel 347H tubes are available in various shapes, sizes as per the requirements of our clients.