As already described before, the most used flange types acc. to ASME B16.5 are: Welding Neck flange, Slip On flange, Socket Weld flange, Lap Joint flange, Threaded flange and Blind flange.
Pipe flanges are method of connecting pipes, valves, pumps and other equipment to form a piping system.
At some point, with all the possibilities of thread form, diameter, and pitch, you need to send it off to SK Grimes or another machinist.
Dimensions from carbon steel and stainless steel flanges are defined in the ASME B16.5 standard. The material qualities for these flanges are defined in the ASTM standards.