Drills and Taps
What are Drills and Taps?
Think of it like this:
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Drill: You use a drill to make a hole
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Tap: You use a tap to cut threads on the inside of that hole, so you can screw a bolt into it.
So, you drill the hole first, then tap it to add the threads.
Key Terms
- O.D. (Outer Diameter): The width across the outside of an object. For a drill bit, it's the width of the cutting part.
- Tap (Tap Drill Size): The specific drill bit size used before threading a hole. Drill this hole first, then use a tap tool to cut threads.
- Close Fit: A hole drilled just slightly larger than the bolt, so the bolt fits snugly.
- Free Fit: A hole drilled larger than the bolt, allowing the bolt to pass through easily.
Drill and tap chart
