Warm Tips: To extend the service life of the step drill bit and facilitate drilling, some oil should be added before use.When working with a step drill bit, you need to add water to keep the temperature down. Specification: 10 STEPS：1/4", 3/8", 1/2", 5/8", 3/4", 7/8", 1", 1-1/8", 1-1/4", 1-3/8" 118° X-type Split Point - Increases cutting speed with self-centering and prevents walking.Two-flute Design - a faster and smoother cutting, allows particles escape easily. Tri-flatted shank will not spin inside the chunk, compatible with different types of drill machines effectively. Application - suitable for sheet metal, plastic, aluminum alloy, copper, NOT recommended for high carbon steel, hard metal.