Seatbelt attachment points are subject to specific safety requirements, and the same applies to seatbelt mounting hardware.
Since the 1960s, these requirements have been standardized, and seatbelt mounting bolts must have an American UNF thread. This thread is obviously found in the bodywork, and is therefore specifically designed for seatbelt attachment.
On our Volkswagens, in addition to the UNF thread, the bolt head is lower, but with a 17 mm metric wrench and available in two versions: bolts with full thread, which are used for fixed seatbelt parts such as belt recepteurs de ceinture, cassettes de ceinture and belts abdominales, and bolts with a threadless section which are intended for parts of seat belts which must remain rotatable, as is the case with three-point belts.
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