This part is listed by BMW as BMW part number 18301317898 (18-30-1-317-898) and is described as Genuine BMW Exhaust System M10 Hex Nut as used on many BMW exhaust systems.
This special nut was used on front flange to the catalytic converter on several BMW "M" engines, including the S38 (E34 M5), the S54 (E46 M3, Z3/Z4 M Roadster Coupe), the S65 (E90/E92/E93 M3 V8), the S85 (E60 M5 and E63 M6). This nut was also used on the Alpina B7 (E65 chassis).
Most BMWs that use this special nut use a total quantity of 4. This nut is sold individually, so be sure to order enough for your BMW.
While other copper nuts may be used, this is the "correct" Genuine BMW nut, appropriate if you are retaining all factory parts and hardware for your installation.
For full BMW fitment information or for assistance from one of our BMW experts, we recommend calling us at 877-639-9648.
E46 (99-05) > M3
E90 / E91 / E92 / E93 (06-13) > M3
E34 (89-95) > M5 (91-95)
E60 / E61 (04-10) > M5
E63 / E64 (04-10) > M6
E36/7 / E36/8 Z3 (96-02) > Z3 M - S54
E85 / E86 Z4 (03-08) > Z4 M