Unusual box of taps that have me stumped

[amecks]

Thanks.  I gave these to friend who will be more likely to use them than I.  I'll pass the info along.
Al

[bgarrett]

My best friend came by yesterday wanting a 1/4" X 24 bolt.   I gave him one  :)

That's an odd one.
Where did YOU get it?

The 1/4 X 24 is National Standard, used on my old Harleys.  He needed it for a hit n miss engine. I bought a new set

[bill300d]

The NS series is a catch-all category for threads which have the American Standard form, but whose pitches are not in the National Coarse or National Fine series.