Here's the SS "button head" machine screw on my daisy wheel repair.
I think it looks pretty good.
Same OD as the rivet head.
That looks very nice, what sized drill bit did you use to drill it out?
I think It was
about 1/4" 19/64" (pro-type 135 degree) and I didn't want to blast through and take the chance of damaging anything.
I used that bit because it was sharp and large enough to cut away at the rivet flange (inside the kettle). Go slow and lightly tap with a center punch (and hammer) to check progress.
Do not drill through with this size bit...the hole in the kettle needs to remain at 1/4"
Instead I went slowly and just thinned the rivet flange until I could manually push it out.
The bit never touches the kettle.
The 135 degree business describes the cutter angle on the bit....consumer grade bits are "pointier" and are not a good choice for this.
Also did you use a lock washer on the underside to keep it from coming loose?
No, the better solution is a lock nut and a cut (flat) washer for it to ride against.
I used a Weber lock nut which looks like a Nylock nut except no nylon insert.
A lock washer would be OK if you were never going to move the daisy wheel....the back and forth action might loosen it, otherwise.
Even the lock nut could loosen, I suppose.
Another way to look at is that you are trying to simulate a rivet flange, so you want all the locking to occur at the nut.