Rivet Nuts and Rivet Studs

[Jay H 237]

We've never used them on 237's robots but we do use them on some of our plastic injection molding robots where I work. They are used on our smaller robots on the lighter duty axis to attach linear bearing rails and brackets.

The ones we have are ribbed on the outside so they "bite" in the hole as you tap them in place with a hammer. Hole size is critical as Al said, otherwise they won't grab. We don't use/have a tool to insert them. Once they are tapped in place the bearing rail is installed. As the screws are tightened the rivet nuts expand and hold in place for good. We use rib washers* and Loctite too, either 222 or 242, depending on the size of the screw. Vibration and loosening fastners is something we're very worried about with our equipment due to the constant movement of the robot and the press and even vibratory bowl feeders when used.


*Rib washers are these things. I've never seen them used anywhere before other than all of our equipment. Might be a European thing . Rib washers aren't anything you'll find at Home Depot or Lowes either. We never use regular split lock washers.