Spoke too soon - Alien sight mounting holes not threaded

[coolsam402]

how much do they usually cost

[MLN1963]

You can get a cheap Tap and Die set from harbor freight for $11.99 and up.

http://www.harborfreight.com/hand-tools/tap-die.html

[gravedigger]

how much do they usually cost

if your going to buy a tap and die set then i would buy a decent set.ya really dont want to go too cheap on something that with make threads.i would check out napa.

[SJunior]

Rather than buying a set, probably be easier to take it to a machine shop and have them do it. I have a Snap On set that I have only used a couple of times and I work on cars for a living. Cheap sets don't hold up and it's no fun trying to get a broken tap out of something your working on.