When it comes to insulation fasteners and stud welding, the right grade of stainless steel must be used to ensure proper performance. There are several different grades that meet the requirements of the varying applications, and it’s important to know which one is best for you.

Material being used for insulation fasteners must fall under the guidelines of the American National Standards Institute (ANSI) and the American Welding Society (AWS). The recommended stainless steel grades are 300’s, and typically these are non-magnetic in their normal annealed state. Under ANSI guidelines, these include: types 302, 304, 305, 309, 310, and 316. 304 (now called 18/8) and 305 are the most common, while the L series (i.e. 316L) is preferred when corrosion resistance is important.

For higher heat exposure applications, 310SS or 330SS are preferred, and for extreme temperatures, the Inconel series 601 is used for insulation fastening and refractory applications. More specifically, when it comes to heat resistance, the grades of choice are as follows: 302/304/305 for 1400°F; 316 for 1700°; 310 for 1850°; 330 for 2,000°; and 601 for 2,200°.

When looking for the right stainless steel for your particular application, keep in mind that not all grades are readily available at all times. 304, 310, and 316 are typically easy to obtain, while others might require special order.

Knowing the right grade of stainless steel for your needs will guarantee the material meets your demands.