Webb Wheel says its 76864 brake drum should only be used for standard duty, van, tractor-trailer or flatbed combinations. Standard duty cycle is considered typical line haul, over-the-road applications. Webb says that duty cycle is independent of gross axle weight ratings.
The 76864 drum is not recommended for liquid and dry-bulk tankers, dump trucks, dump trailers, refuse applications or other similar applications.
For heavy-duty cycle applications (applications that are subjected to a higher frequency of mechanical and/or thermal cycling compared to standard duty), customers should use Webb Part No. 66884 for 16.5 x 7 brake size.
