I want to galvanize some embed parts to ASTM A153, but my galvanizer does not have a centrifuge or spinning system.  Is that an issue?

ASTM A153 is the hot-dip galvanizing specification for hardware and fasteners that are spun or otherwise handled (torch and steel brush) after galvanizing to remove excess zinc. ASTM A123 is the hot-dip galvanizing specification for most other items (except single reinforcing bars). However, there is an instance when A123 is the appropriate specification to use when galvanizing steel parts containing fasteners or other hardware. A123 is appropriate when the fasteners or hardware have been welded onto a slate or other piece of steel. This makes sense when considering a piece of hardware welded onto a large fabrication that is too big to be spun, but it may not seem so obvious when looking at smaller assemblies that may be made up of two or three small pieces of steel.

ASTM A153 discusses the requirements for galvanizing single items only, not assemblies. In other words, if you are galvanizing single items of hardware or fasteners, A153 is the correct specification to use. If instead, you are galvanizing fabrications or assemblies (welded or otherwise fastened together) of hardware and fasteners, then use A123. This topic may seem trivial, but when it comes to dealing with a by-the-book inspector it could mean the difference between passing inspection and having to re-galvanize an entire job. So, when galvanizing these types of hardware assemblies, it is best to specify A123, which does not require spinning or centrifuging after galvanizing.