A sub is a special short length of threaded pipe used to connect drill pipes to drill collars, with a drill pipe connection on one end and a drill collar connection on the other.
When a bit sub is used to convert connectors of different types or sizes, it is called a crossover sub. The sub that connects the drill bit to the last drill collar is the bit sub.
Products are manufactured in accordance with API Spec 7 RP7G as applicable.
There is a wide range of subs available, including:
- Straight Crossover Sub (Box/Pin, Box/Box, Pin/Pin)
- Bottleneck (reduced section) Sub (Box/Pin, Box/Box, Pin/Box, Pin/Pin)
- Crossover Sub with Float Bore (Box/Pin, Box/Box, Pin/Box)
- Bit Sub with Float Bore (Box/Box)
- Bit Sub without Float Bore (Box/Box)
- Top Drive Saver Sub (Pin/Pin)
- Kelly Saver Sub without rubber protector (Box/Pin)
- Kelly Saver Sub with a stretched on rubber protector (Box/Pin)
- Lift Sub (18 deg taper or square shoulder) (None/Pin, Box/Pin)
- Lift Plug (None/Pin)
Options:
- API Pin Stress Relief Groove and Box Boreback
- Cold Rolling
- Phosphate Coating
- Proprietary Connections of Leading Manufacturers
- Proprietary Connections of Leading Manufacturers
- Rubber Sleeve Protectors (For Kelly Saver Subs only)
- Third Party Inspection
