6.5 Inches

6.5 inch drill bits (165.1mm) serve drilling operations that need slightly more annular space than a standard 6" bit provides, often for improved cuttings transport or larger casing programs. This size is commonly specified in intermediate hole sections, water well completions, and mining boreholes where the extra 0.5 inches makes a meaningful difference in drilling fluid velocity and hole cleaning efficiency.

Core Advantages:

- Full range of bit types: PDC, tricone TCI, milled tooth, and natural diamond

- API 3-1/2 REG pin connection as standard (custom threads available)

- Better hole cleaning characteristics than 6" due to larger annular velocity

- Compatible with 5-1/2" and 6" casing strings

- Balanced cutting structure for stable performance in interbedded formations

- Suitable for depths up to 3,000m depending on formation hardness

Q: Is a 6.5-inch bit better than a 6-inch for water well drilling?

A: It depends on your casing program. If you plan to run 5" casing, a 6.5" bit provides better annular space for gravel pack installation. For 4" casing, a 6" bit is usually sufficient and more economical.

Need 6.5-inch bits for your drilling program? Get in touch with your well profile and we'll provide a tailored quote within 24 hours.