Thermal Cutting Lance Thermal Cutting Lance uses a bundle of iron,alloy or magnesium rods inside hollow steel tube to create a self-sustaining and extremely hot cutting flame which can cut through just about anything. The high temperature(7000 to 8000F, or 3,871C to 4,426C) generated is greater than the melting point of any known substance - with diamond having the highest at 3,547C(6,416F).