I cut 12 holes with a 3/8-16 combi tap in a 1/4" steel angle in less than 20 minutes! The holes were already drilled but using the threading tool was very easy I wasn't sure what to expect when I ordered the set but the price was good so I took a chance I didn't have to worry the tool cuts nice sharp threads and makes it easy to thread even 1/4" thick steel. Buy with confidence.