Casing coupling
Casing coupling is for the dimensions more than 4 1/2 inch. Differently than tubing coupling is, casing coupling normally does not need to be thickened (Non-upset), which means no upset casing coupling, so it has following types:
Round thread • LTC/LC: Long round thread casing coupling
• STC/SC: Short round thread casing coupling
Buttress thread • BTC/BC: Buttress thread casing coupling