ELBOW 7N9008 - Caterpillar

All Caterpillar ProductsThe use of worldwide sources for components has made it possible for truck engines to have a mixture of inch and metric fasteners. For example, metric fasteners may be used in electric starting motors, alternators and other components that are purchased and installed by Caterpillar. It is possible that the internal bolts on a component may be metric while the mounting bolts may be inch size.
To help the serviceman know when metric fasteners are used on a product, future service publications such as Parts Books, Operation and Maintenance Guides, and Service 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 vehicle 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 same part no. and grade or better.