I purchased 2 of these the other day. I've threaded over 200 holes in steel without much issue.
http://www1.mscdirect.com/CGI/NNSRIT...er=346%50mode=
if the link doesn't work - go to
www.mscdirect.com - search for item #64510019 on page #325
for a drill bit I 'm having real good luck with these also
http://www1.mscdirect.com/CGI/NNSRIT...MPXNO=12580872
if the link doesn't work - go to
www.mscdirect.com - search for item
#81134058 on page 49