There are two constants when it comes to the type of parts used on modern electric guitars:

• ALL GIBSON® guitars made in the USA (vintage, Custom Shop, USA models, etc.) use all INCH (Imperial) tailpiece bushings.
• ALL Imported guitars (guitars not made in the U.S.A.) use METRIC parts

Other than those, things can get a bit confusing. Let’s examine a few of those:

• Gibson® guitars with NASHVILLE bridges: these guitars use METRIC parts for the bridge and bridge posts, and INCH tailpiece studs.
• Heritage® guitars: are made in the U.S.A. and have essentially the same bridge system as a Gibson® with NASHVILLE bridges, but they use METRIC tailpiece studs in most cases. However, they sometimes use INCH (Imperial) tailpiece bushings. This should be checked before ordering tailpiece studs, such as the Faber® Tone-Lock™ locking tailpiece studs and spacers.
• Other AMERICAN brands that are made outside the U.S.A.: these guitars use ALL METRIC parts and, for the purpose of parts selection, should be considered as “imported.”