ASTM A268 and ASTM A270

ASTM A268 and ASTM A270 are two prominent standards for stainless steel tubing, each serving distinct industrial applications. ASTM A268 covers seamless and welded ferritic stainless steel tubes for general corrosive service. These tubes are commonly used in applications involving high temperatures or corrosive environments, such as heat exchangers, condensers, and feedwater heaters in power plants, as well as in various industrial process piping systems. Typical grades under this specification include TP430 and TP444. In contrast, ASTM A270 is the standard specification for seamless and welded austenitic stainless steel sanitary tubing. This standard is specifically designed for applications demanding the highest levels of cleanliness and hygiene, primarily in the food, dairy, beverage, pharmaceutical, and bioprocessing industries. Tubes conforming to A270 feature highly polished internal surfaces, known as finishes, to prevent bacterial growth and allow for easy cleaning. Common grades under A270 include TP304 and TP316L. While both standards govern stainless steel tubing, the key difference lies in their purpose: A268 is for general industrial corrosion resistance, whereas A270 is dedicated to sanitary and hygienic service.**