Bolt type misnomers

[Grampster]

In the ASME Piping and Fittings catalog, there are four types of bolting listed: machine, stud, lug, and machine lug. The only two that are viable are machine and stud. In piping, stud bolts are usually threaded rods with nuts on both ends.

This from the American Fastener Technologies Corp: 'never heard of 'lug bolts' used in anything but a truck or auto reference'. One type of lug bolt is used to keep wheels on vehicles. Machine lug bolts are basically the same thing; they both have some type of a head, either a hex or one to keep the bolt from turning when a nut is added. 

Unless someone can prove me wrong, lug bolts aren't used in piping systems.

[Grampster]

FYI additional information. The SampleProject model uses "lug bolts" with "lug-style" butterfly valves. There are two basic styles of these valves - Half-lug (lugged) and full-lug. The lugged are threaded and normally used at the end of a line; two sets of machine or stud bolts are used (not lug bolts). The full-lug valves have non-threaded pass-through holes and use one set of stud bolts for assembly. The valve name is not meant to indicate the type of bolting used.