In general, three conditions are required for a fastener to stay fastened. One, there must be sufficient clamping load to prevent relative movement between the joint faces. Two, the clamping load must be greater than the cyclical loading imposed on the fastener by loading or vibration, or whatever. Three, the sum of the underhead and thread friction must be greater than the unscrewing torque generated by the clamping load and helical thread. Satisfy these and the joint will not come undone, and it doesn't matter what sort of washer is used, but spring washers do assist with underhead friction. The boltscience page shows a bolt with inadequate clamping load reacting to a shear force across the joint. It was going to loosen whether or not the washer was there.
Big End Advise Please
|
« Next Oldest | Next Newest »
|
Users browsing this thread: 3 Guest(s)