[3  & 8 D x 1  & 4 SHK]

[5  & 8 D x 1  & 4 SHK]

[1  & 2 D x 1  & 4 SHK]

Flat bottom counterbores for using round head screws, Hex bolts, etc. Includes pilot drill, #55288, (D) Diameter: 5/8, (D) shank: 1/4, overall length (L): 2-3/4, D1: 1/4, replacement drill: 630-70255288 carbide Tipped Counterbore 5/8 dia x 1/4 Quick release hex shank