Addi Turbo vs Boye or Susan Bates Needles

Are the Addi Turbo (made in Germany) larger in circumference than the American made needles? I purchased size #9 straight needles which is equivalent to a #10 Boye or Susan Bates. Now I have to purchase the Addi Turbo #8 in order to complete my project. (All #9s are listed with 5.5 mm. by the manufacturers.) Has anyone had this experience? :mrgreen:

I haven’t noticed that large a difference but in the smaller sizes I have seen a couple of different mm sizes lumped as one American needle size.