The entry for this coin at
https://en.numista.com/catalogue/pieces11287.html lists the thickness as 6 mm, which I'm certain is in error. I don't have an authoritative source for the proper dimension; my Krause doesn't list it, and the example in my collection is a known counterfeit. The previous 1 piastre issue (KM# 5) was 2.7 mm thick, which is in line with my fake and seems much more reasonable to me. But hey, I've been wrong before.