API 5CT J55 and K55 Oil Casing including short round thread casing (STC), long round thread casing (LTC) and buttress thread casing (BTC). STC and LTC both feature a non–runout design of round threads STC (Short Thread Coupled) BTC (Buttress Thread Coupled) LTC (Long Thread Coupled) EUE (External Upset End) NUE (Non Upset End) LP