5 Pcs Four Spiral Flute Step Drill Bit Set 6 Pcs Countersink Drill, Plastic 5 PCS Step Drill Set: Constructed with HSS material ensures they stay sharp and sturdy through various projects. Surface Nitride Coating can keep sharp and prolong service life. Four Spiral Flute design ensures precise and accurate drilling. The four-flute step drill bit is smoother cutting than conventional two-straight flute step drills. 6 PCS Countersink Drill Bits: Crafted from M35 High-quality cobalt material. Superior strength, heat resistance, and durability. Five-flute design reduces vibration and removes chips better. It goes through like butter and leaves a very nice bevel on drilled holes. Our 11 Pcs nitriding step and countersink bits set includes a range of sizes to cater to various drilling needs. The set comprises step bits with diameters of /16"-1/2" (6 steps), 1/8"-1/2" (13 steps), 1/4"-3/4" (9 steps), 3/16"-7/8" (12 steps), and 3/16"-1-3/8" (19 steps). Countersink Drill Bits sizes1/4'', ?3/8'', 1/2'', 5/8'', 3/4'', 5/16". Precision Grinding: If you're going for smooth and efficient, these drill bit sets can be used to drill holes in stainless steel, carbon steel, iron, copper, aluminum, and most other metals as well as wood, plywood, etc. All-in-One: One-piece built solid 1/4" Hex Shank on all for positive drive and quick change. Each cutout is marked for the size of each bit. Having a solid case to keep the bits nice and sharp vs just rolling around with other metal bits. Very versatile, do-it-all kit. Our Commitment: We take pride in delivering a quality product. Whether you're working on a big project or a quick fix, our step drill bits are your go-to tools. Any problem can be solved. Buy with confidence and add to cart now!