M6 x 40mm stud which was used as an exhaust stud on the Honda CB500K and CB550. If you're installing a new exhaust and you have some questionable threading on the studs, spring for some new studs! We have threadlock available separately. If your replacing all the stud's you'll need 8 of these.
Replaces Honda Part Number: 90044-323-300
CB500K Four - 1971-1973
CB550F Super Sport - 1975-1977
CB550K Four - 1974-1978