Norris manufactures its cylinders using the Hot Billet Pierce method of manufacture. Step 1 Steel Billets of Chromium Molybdenum Steel are cut into Mults. Step 2 Mults are preheated in an induction heater until near molten state. Step 3 A Robotic arm places the mult into a piercing press. Step 4 The "mult" is then pierced. Step 5 The pierced mult is pushed through a series of roller dies creating a cylinder with a smooth uniform wall.