Wera the hell do I figure out screwdriver sizes?

[Air21]

Howdy!

I need to pick up some screwdrivers for A&P School and I already have a Wera set in my box at work (machinist). So I do some snooping around KC Tool and Chads Toolbox. I have the money to spend so I figured I'd take a step up from the Wera Classics I use around the shop and switch to Kraftform Plus with the laser tip after watching THIS (skip to 4:00) review.

Now my tool list calls out the following screwdrivers:
1" long slotted
4" long slotted
8" long slotted
1" long #2
4" long #1
6" long #2

And I can appreciate that sizes are going to be a little off on account of the metric system, it looks like I may lose a little in length, but I am erring on that not being critical. What's getting me on the slotted screwdrivers is all the tip dimensions!

Here you can see the table of sizes. I picked the "Aerospace" ones for simplicity reasons, because there are fewer options than a more general set. I understand the length measurements no problem, but the tips? How wide do I want? How thick?

I walked into a Lowes and looked at screwdrivers in the lengths I need and they only give two dimensions, length and tip width, nothing about thickness. I suppose I could go back with my calipers and check them all. But as far as you all know, are there more common tip thicknesses? I notice in my Classic set that some of the tips run small, and that in the chisel drivers above they look like they run large. Prices are about the same online, I just don't want to be the guy with tips that wont fit in the screws, or that are too small.

Thanks in advance!

 

[JR 42]

This page has a couple charts for screw head slot specs, nothing about where the numbers came from though (seems like there would be SAE or ANSI standards somewhere, didn't find them with limited googling).

(A few probably dumb) questions...
A&P is aircrafts mechanics, right? Aircraft are pretty much all SAE, so wouldn't inch pattern slotted screwdrivers fit a little better? I'm assuming a 6mm slotted tip is really 6mm and not 1/4", and vice versa.

JR

 

[JR 42]

Poked around the internets a little more, ANSI has standards published for pretty much every type of fastener, but you have to buy their publications to access the full documents easily. If you look around on the ASME pages here you can find the specific standard title, then google it to find partial results like this.

Some tool manufacturers have pretty good info on their screwdriver tip sizes, like this Armstrong page here (click on the "specifications" tab to see the tip thickness). It looks like Wera also lists the tip thicknesses of their slotted drivers, in mm.

JR