304H

Grade 304H has higher strength at elevated temperatures so is often used for structural and pressure-containing applications at temperatures above about 500°C and up to about 800°C. 304H will become sensitized in the temperature range of 425-860°C; this is not a problem for high temperature
applications, but will result in reduced aqueous corrosion resistance.

The outer diameter of 304H stainless steel pipes typically ranges from 1/8 inch (3.175 mm) to 48 inches (1219.2 mm) or even larger. The common standard sizes for industrial applications are often available in increments of 1/8 inch or 1/4 inch.