Drillstring Accessory Rentals - Bit Subs

Bit subs are used to connect the drill bit to the bottom hole assembly (BHA). They are usually a box-by-box connection (female x female).

Drill bits have a pin connection which, depending on the size, has a different API regular connection. The bit sub is usually bored for a float valve which is used to control backflow up the drill string to the rig floor.

Bit Subs