Some tapping and reaming questions

[Chiro75]

Ever notice that most of my questions are sort of basic? I never had the chance to take shop or anything, so I sort of skipped the basics and went to the more advanced stuff!

I'm thinking about making a balisong (butterfly knife) as my next project. I have some questions:

1) For a precise fit of holes and pins I know it's best to drill first then ream the hole to the precise size. Let's say I want to do this with a 1/8" hole. Would I drill my 1/8" hole, then use a ream to get the size precise, or would I drill one size down from 1/8" and ream at that time?

2) Let's say I want to tap threads into a hole. I assume, then, I would do whatever the recommended steps are from question #1 (drilling and reaming), then tap after that. What's about the thinnest titanium I would want to tap for threads? I'm thinking about attaching a G-10 of CF scale to a thin piece of Ti with screws.

Thanks in advance, and I'm sure more questions will follow as this project unfolds!

 

[RARanney]

Drill the hole slightly undersize, then ream up in size to match your pivot pin's ACTUAL measurement. Folder makers drill liner thickness titanium all the time. A sixteenth, or even .040 will work. Titanium is tough and only requires a few threads to grab the screw. There are some folder making tutorials somewhere around here that will help with what you are doing.

 

[mete]

You wouldn't have to ream a hole that is going to be tapped.ALWAYS use lube when threading. For thin stock use fine thread such as 8-36 rather than 8-32 and if more than 1 tap drill is listed use a smaller one.