Adjustable tap wrenches and die holders are grouped under the generic term holding tools.
Adjustable tap wrench
Hand taps are picked up with tap wrenches. The square of the tap is screwed tight between the adjustable clamping jaws. Due to the adjustability of the clamping jaws, taps with different square sizes can be fixed. The clamping jaws are moved by turning an arm of the tap. The length of the arms of the tap wrench creates a leverage effect which facilitates cutting by hand. Screw extractors or hand reamers can also be operated with a tap wrench. Due to the design of the tap iron, the plumb line of the tap is facilitated. The design elements of the adjustable tap wrench have been known for over 100 years and have remained almost unchanged since then. The materials, however, have changed. Today the bodies are mainly made of zinc die-cast instead of grey cast iron.
Die holders for holding round dies were unknown at the beginning of the last century. External threads were cut with oblique or straight dies, which later became “out of fashion” and were replaced by round dies. Round dies are inserted into the die holder and fixed with the five retaining screws. Today the body is usually made of die-cast zinc.