Hmm... that's a diameter difference of 0.1900" for the #10, versus 0.1969" for the metric M5. The M5 might be a little bit tight to screw in but probably close enough for government work;
pitch being equal. However, if I read the thread pitch of the metric screw as being 0.8mm per turn, then that's way too small (fine). The screw I measured last night had a thread pitch of 0.08" or 2.03mm. Seeing as how 12 threads per inch works out to 2.11mm, you'd have to get a M5-2.1 screw
if they even make one. I looked through the McMaster-Carr catalog and could not find a metric sheet metal screw with those dimensions. Largest pitch I see for M5 is 1.25mm for any type of screw.
Now, since I believe that the hole that the license plate screw goes into is actually a plastic insert, you might be able to get away with using a different screw pitch. But since the original screws have a wider pitch you could end up stripping the plastic receptacle.
Had a thought.... why not look up the part number in the online Parts database. Imagine this.... there's
two different part numbers (and quantities) for these screws:
4
SCR,TPG,5xPT-12[St],ZnNi BLK-R , Rear License Plate Screw 1019047-00-D Over-the-Counter(No VIN) $0.00 2
4
BOLT,PN,PZ,M5-0.8x6,[88],G1009, Rear License Plate Screw 1453796-00-A Over-the-Counter(No VIN) $0.00 4
The first number in these strings is the part number reference from the diagram of the license plate assembly. The last number is the quantity involved. First line I decoded as being a SCREW, while the second line is a BOLT. Screw has a size(?) of "5xPT-12", while the bolt is definitely a metric "M5-0.8". This all seems to say that there's two different fastener systems used on the Model 3.
My car was delivered July 2018 and is a June build.
ref:
https://epc.tesla.com/#/systemGroups/47314
