And there we have it- when does a common washer become a NLA shim?
Only when BMW says so....
For further guidance I offer up an non-independent assessment:
Understanding Washers and Shims
Here at Sfdon Parts Sales , there are some questions that we hear more often than others. One particular topic that people often are confused about is the difference between washers and shims. They can seem very similar, but it is important that you understand these tools if you plan on using them. Each one serves a different purpose, so in some situations one will be preferred over the other in order to get the results you want.
Note that Washers have been used as spacers in the past because they can get the job done. Most people only use washers as a temporary spacer until they can replace it with a more permanent, appropriate part. ..
A Shim.
Hope this clears everything up..........