Product Specifications: Groove Diameter/Weight: 1/4" (6.4 mm) / 106 g 5/16" (8 mm) / 131 g 3/8" (9.5 mm) / 154 g 1/2" (12.7 mm) / 195 g 9/16" (14 mm) / 214 g 5/8" (16 mm) / 222 g HRC 48-50 Steel: Made of special heat-treated steel, these drill bits feature high hardness up to HRC 48-50, thin cores and high concentricity for extended use. 6 Slot Diameter: A set of 6, these saw heads have diameters of 1/4" (6.4mm), 5/16" (8mm), 3/8" (9.5mm), 1/2" (12.7mm), 9/16" (14mm) and 5/8" (16mm). Product Description: Double-acting pairing: It can be used in conjunction with tenon and tenon to achieve double effect. Drilling square holes requires tools such as electric drills and electric hammers. Wide applicability: They are excellent accessories for mortises, chisels and woodworking in construction, installation, renovation, decoration and other industries. Service: We sincerely hope that you can have a good shopping experience in our store, if you have any questions, please feel free to contact us. luckymeet