GESchwarz
Well-Known Member
I am of the belief that the best way to drill a hole through two pieces of sheet metal is to first drill all of the holes with a smaller drill, #40 for instance, then re drill the whole assembly to the finished size, #30 for instance.
1. The reason is that sometimes drill bits can make holes just a little oversized.
2. Under the force of the drilling operation the assembly may shift just a little, causing the two parts to have holes that are slightly our of alignment.
In both cases the problem can be fixed when the hole is enlarged with the larger drill bit using the lighter pressure required.
The strongest rivet joints are going to be the ones where the holes are all as tight as they can be. The oversized holes do not take up the load until the other, tighter holes have already begun to distort.
I'd like to hear from some people who have a lot of hole drilling experience.
1. The reason is that sometimes drill bits can make holes just a little oversized.
2. Under the force of the drilling operation the assembly may shift just a little, causing the two parts to have holes that are slightly our of alignment.
In both cases the problem can be fixed when the hole is enlarged with the larger drill bit using the lighter pressure required.
The strongest rivet joints are going to be the ones where the holes are all as tight as they can be. The oversized holes do not take up the load until the other, tighter holes have already begun to distort.
I'd like to hear from some people who have a lot of hole drilling experience.
