C-: Step drill bits feature a triple-flute design for increased stability, effectively reducing deviation during the cutting process. Additionally, the 'C-profile' ensures smoother cutting and an increased cutting speed HSS Step Drill: Made of high-quality Material, through heat treatment, achieves toughness and bending strength that surpass standard high-speed steel, making this step drill bit more suitable for cutting hard materials Easy to Install: Its structure and dimensions are rationally designed to adapt to the power drive, making it easy to install the drill, and the drill can also be installed without any problems, which saves operating time during the preparation phase Easy to Use: The tool's characteristics suitable for the production of round holes, helping the user to create holes with smooth surfaces and clean holes that are as close as possible to the ideal round hole shape Wide Range of Applications: It is well suited for drilling different types of textures, including hardened steel, softer brass, and common texture such as wood and plastic Colour:Black Material:iron Please Note: Material thickness: Suitable for metal sheet up to 1/8 inch (3 mm) thick and stainless steel sheet up to 1 mm thick. Add cutting oil or use coolant during continuous operation. Due to the larger cutting angles, the startup speed may be slower Package Contents: 3 * Step Drill Bit Set(4-20 4-22 4-32 model) Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.