4-40 Drill-Tap question

For a 4-40 screw you need a 4-40 tap, a #43 bit for the tap hole and a #33 for the through hole.
 
For future reference Dan Gray has this great chart, too:
http://www.knivesby.com/drill-tap-chart.html

Only thing missing that I can see, which would be nice, would be a column for the clearance drill bit size. This would be useful for folders where you would possibly tap one hole but the matching hole on the opposite scale is drilled through so the screw can clear it. But, beggars can't be choosers! ;) For once I beat Dan to posting this chart's link! YES! :D
 
Arthur,why would you need to bit sizes,why not just drill the hole with the #43 and came back and tap it??
 
The #43 is what is used for the tap hole. The #33 is if you need a hole for the screw to pass through. I wasn't sure if you needed both bit sizes since you didn't post what exactly what you were using the screw for.
 
Are you tapping Ti? If you are, go with one size larger drill bit than what is normally recommended.

Also, there are different size taps for the same size hole, H2 is probably the most common size used. The range is H1 to H9, with H9 being the largest in diameter and giving the highest percentage of thread depth.
 
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