This is the most common profile for surface-set diamond mineral exploration core bits and is the standard profile for all core bits with kerf widths of 0.39 inch (10 mm) or less. Semi-round profile core bits are cost effective in that they generally have a lower overall total set carat weight than core bits with comparable kerf widths and nominal diamond sizes that use other bit crown profiles. The application range of the semi-round profile is extensive and is suitable for use in soft to hard formations and is particularly well suited for use in fractured formations.

The application of this profile is primarily on medium to wide kerf wireline mineral exploration surface-set diamond core bits that are used to drill medium-hard formations. This profile will provide good stabilization where hole deviation is a problem and will usually yield a higher rate of penetration than any other surface-set diamond core bit crown profile. As the nose or “pilot” of this profile is relatively fragile, it is not recommended for use in heavily fractured formations. As the geometry of this profile is not well suited for the setting of large cutting elements, stepped profile surface-set diamond core bits are generally supplied with natural drill diamonds in the 10 SPC to 100 SPC size range.