How do I tell the difference between a 5/32 and a #6 dimple die?

CubedRoot · #1 02-09-2017, 04:34 PM

I am about to start working on the elevator trim support plate and I need to dimple for a #6 screw and its associated nut plate.

However, I have a weird problem. I have a 5/32 dimple die and a #6 dimple die, but I cannot tell which is which! There are no markings on the sides of the dies, nor on the backs or shanks. One of them is slightly smaller than the other, but I have no idea which one is which.

The hole in the E-615PP for the nutplate and its screw are pre-drilled, and one of these dies actually fits into the hole snugly but the other doesn't. I have also not drilled on these holes yet, as the plans don't necessarily call for me to.

So, should I just use the dimple die that fits in the pre-drilled hole for the #6 screw on this plate and then mark it as the #6 die? Or am I missing some more obvious here.

Thanks!

BobTurner · #2 02-09-2017, 04:53 PM

Well, the recommended hole for a #6 screw is to use a #27 drill, which is 0.144". 5/32 = 0.156". So I'd guess the smaller dimple set is the one for #6 screws.

Lars · #3 02-09-2017, 05:25 PM

Dial caliper. After a bazillion dimples my eye is reasonably well-calibrated, though not infallible. If I doubt myself the caliper doesn't lie. If you don't have a caliper, I'd recommend one. Pretty handy measuring device as you get into your build. Digital ones work fine too, though I like the never-needs-a-battery feature of my old school Mitutoyo. Or (gasp) go really old school and find a vernier style.

fcordrey · #4 02-09-2017, 05:51 PM

Quote:

Originally Posted by Lars

Dial caliper.

What he said. You'll end up using them for all kinds of things.

I started with the cheap digital ones and ended up getting a better digital set. Got tired of the batteries being dead when I really needed to use them so I finally ditched them and now have three different sets with a dial face.

I'd say get a decent dial caliper and micrometer.

rv7charlie · #5 02-09-2017, 05:55 PM

And you don't need to break your tool budget for something like this. Harbor Freight sells several models for <$20; sometimes under $10. If you're considering a career as a machinist, go big, but 'better is the enemy of good enough'. :-)

Charlie

mturnerb · #6 02-09-2017, 06:27 PM

I keep one of these on the bench all the time. Cheap and works great:

http://www.harborfreight.com/6-inch-...per-93293.html

Kyle Boatright · #7 02-09-2017, 06:34 PM

Drill a #27 hole. See which pilot fits.

CubedRoot · #8 02-09-2017, 09:57 PM

Quote:

Originally Posted by BobTurner

Well, the recommended hole for a #6 screw is to use a #27 drill, which is 0.144". 5/32 = 0.156". So I'd guess the smaller dimple set is the one for #6 screws.

Found the right dimple die :-) Bob's measurements helped a ton, and then I used the smaller dimple die for the hole and the screw fit perfectly. I have marked the back side of the die with 6 so I know which is which now.

I do have a set of the harbor freight digital calipers and use them a pretty good bit. They are handy!

Thanks everyone!