Irwin Tools 1840235 Performance Threading System Self-Aligning Tap Set-Machine Screw/Fractional/Metric, 41-Piece Contains SAE Self-Aligning Taps, Metric Self-Aligning Taps and Drive Tool System All Taps are constructed of High Carbon Steel Laser Etched Markings for easy identification Die lock ergonomic die handle that also accepts two different adjustable tap sockets