#30 vs. 1/8

[rotoiti]

Again, a n00b question:

The instructions say to match drill with 1/8 (0.125) bit. Would #30 bit be too big (0.1285)? Avery seems to use 1/8 and #30 interchangeably.

[rockwoodrv9]

I know for the 9a I am building, I went to HF to get bits and bought a bunch of 1/8" bits. I must have bought 50 of them. I still have almost all of them and have re-ordered #30 and #40 bits several times. I don't think I ever used 1/8" for anything? The thing I really liked was using a reamer over a drill bit for the match drilling. No need - or very little need to deburr when you use a reamer over a bit.

Get a couple of these and you will be happy.

http://www.averytools.com/prodinfo.asp?number=15375

[roee]

Originally Posted by rotoiti

Again, a n00b question:

The instructions say to match drill with 1/8 (0.125) bit. Would #30 bit be too big (0.1285)? Avery seems to use 1/8 and #30 interchangeably.

If this is for an 1/8" solid rivet (AN470AD4 or AN426AD4), then the final hole diameter needs to be #30 for a proper slip fit (an 1/8" rivet won't slip into an 1/8" hole).

How you end up with a #30 hole depends on the situation. But one good general approach is to get your parts to where they're match-drilled (or pre-punched as the case may be) to 1/8", i.e. under-sized, and then match-ream them to final size using a #30 reamer bit. This technique will give you good clean concentric holes (proper de-burring still required).

[rotoiti]

I have read up a few points ahead and it says right there: final drill with #30 bit. So there I have my answer

Thanks all!

[az_gila]

Originally Posted by rotoiti

Again, a n00b question:

The instructions say to match drill with 1/8 (0.125) bit. Would #30 bit be too big (0.1285)? Avery seems to use 1/8 and #30 interchangeably.

The rivet specifications give actual numbers.

The "1/8" rivet is actually -

0.125 -0.001/+0.003 = 0.124 to 0.128 inches diameter.

That makes the #30 drill at a 0.1285 a tight slip fit for the largest possible rivet diameter...