This is the tap and tap-drill needed to drill out a broken bolt, or to chase the threads before you install new hardware in your 7.3 liter Ford Powerstroke cylinder heads. Both the drill and tap are quality High Speed Steel (not carbon steel like you find in most hardware stores), but remember, these bolts have seen thousands of heat cycles, which means they are pretty hard, so here are some important tips: start with one or two smaller size drillls and work up to the tap-drill, use plenty of oil, and keep the RPM low to medium. Remember that cutting tools are brittle and can break, so take your time!
NOTE: For clarification, these are meant for use on threads that secure the exhaust manifold to the cylinder head. You will receive one tap and one drill.