Proper tool to measure 90 degrees for pins

[G. Freeman]

Hi Guys,
Is there a good tool that I can measure or make sure that a pin is 90 degrees in relation to the rest of the part as in a 1911 thumb safety or slide stop?

I've tried using a straight edge or triangle but the area that joins the pin to the part is beveled & I coudn't get an accurate measure. Most of these rulers have a very sharp edge.

I know that I can just place the part into the gun, but sometimes I'm lazy in having to disassemble a gun to test fit a part. There are times I just like to keep some parts as spares without pulling apart my gun.

Thanks in advance!

[HiBC]

One way,if you have access to a lathe or a mill or an accurate drill press,would be to drill /ream a hole of the pin size in a piece of flat stock,or if in the lathe,just face the round stock and put in the hole

This is the basic idea of a functional gage.

A vee block may also tell you what you need to know.

[Unclenick]

Note that holes in gun frames aren't always perfectly perpendicular to the sides of the frame, either, so knowing the safety pin is perpendicular to the safety lever and base plate may or may not get you what you are looking for. I designed my own 1911 sear honing fixture long ago because of this. It lets me angle honing across the nose by half thousandths until I get even contact with the hammer hook and sear in a particular frame. No two seem to be exactly the same.