Stainless Steel Round Tubing 304 Rigi-Grip is normally used for aerospace, food and beverage, machinery, architectural, chemical, and cryogenic applications. This material has a diamond pattern etched on it to make it easier to grip without slipping. 304 stainless, the most Common Stainless Steel alloy on earth, provides high strength and good corrosion resistance outside of marine and highly corrosive environments.