Drill pipe is usually the API NC connections: NC50 (also known as 4-1/2" IF) for 5", NC38 for 3-1/2" or 4" pipe (also known as 3-1/2" IF). These are made up to a specified torque... API RP7G has a list of the minimum acceptable make up torques for each NC connection. Other drill pipe connections are speciality higher torque/ larger ID connections. Grant Prideco make a lot of them (HT40, XT39), so do VAM and Hydril. The manufacturers supply min/ max and optimum makeup torques- go to their websites for these data.
Casing and tubing (which are basically the same thing) come in two generic type of connections; API and premium. API connections (8 round and buttress) ARE NOT GAS TIGHT (they rely on dope for the gas seal) and are made up to a marker triangle on the pin. You won't get official make up torque numbers for API connections because of this. Premium connections are gas tight, and are proprietary; the big names are VAM and Hunting, although Hydril, Nippon Steel, Tenaris and all sorts of other people make premium connections, for all sorts of applications: high torque, corrosion resistant, high compression, tight clearance etc etc. In my experience, VAM connections are common in the North Sea and Africa (VAM top is almost the standard connection in the North Sea), and Hunting are more common in Canada & the US. Premium connections are made up to a torque/ turn graph (ie not just to a certain torque, but a certain torque after a certain number of revolutions). If you want, the VAM running book is available on the VAM website, telling you more than you really need to know about VAM connections!
