The abbreviation BSF stands for "British Standard Fine", this is thread with a fine pitch. With the English Whitworth bolts and nuts, it is not the head but the diameter of the bolt that is decisive, so first measure the diameter of the bolt, if it is 3/8 "(9.5mm) then you must use a wrench that is suitable for 3 / 8 ". The key width of the key is 18.03mm.
We sell the fastening materials in assorted bags in the most common sizes 1/4 ", 5/16" and 3/8 ". You can also contact us for individual items, send an email to email@example.com for a quotation.
BSF thread table: Bolt length table:
|Size (inch)||Size (mm)||TPI||Length (inch)||Length (mm)|