Use of washers when assembling structural components 1

[MikeL3]

I need to be educated on whether steel (galvanized) washers should be used on the nut and hex head side of the bolt when joining a vessel platform hand rail to a slotted toe rail. If only one flat washer is called out it seems logical that it would be used at the slot since they are somewhat oversized. The spec only requires the bolts to be snug tight.

The toe rail has slotted holes on the inside and the dwg detail states (Use HHMB W/H.Nut & Flat Washer - on 1 3/8" gage). What does the 1 3/8" gage mean?

 

[IFRs]

Gage is often the distance between bolt centers or bolt center to edge of metal. Washers go over slots.

 

[sdz]

In general a washer is required under EITHER the head or the nut, whichever is being turned during tightening. However this is for normal sized holes. Oversized or slotted holes might require an additional heavy or plate washer, but if tightened from the other side they will also require a normal washer on that side.

 

[IFRs]

sdz - I agree. I assumed that the nut was over the slot and the nut was being turned. This is not always true.