It is possible that the internal bolts on a component may be metric while the mounting bolts may be inch size.
To help mechanics know when metric fasteners are used on a product, future service publications such as Parts
Books and Operation and Maintenance Manuals will use a notice similar to the one that follows:
Caution must be taken to avoid mixing metric and inch (customary) fasteners. Mismatched or incorrect
fasteners can result in equipment damage or malfunction, or possible personal injury. Original fasteners
removed from the vehicle should be saved for assembly when possible. If new ones are required, caution
must be taken to replace with one that is of the same part number and grade or better.