How can you recognise a good adjustable tap wrench?

Recognising high quality winch irons

Adjustable tap wrenches are used to clamp and operate tools with square shank. They are called adjustable or adjustable because the movable jaw can be adjusted to the specific size of the square by turning the handle. The length of the handles creates a leverage effect which minimises the effort required for actuation.

Thus the basics of this holding tool are sufficiently described.

What points should be considered when evaluating the quality of this tool?

It is best to compare a good holding tool with a less good holding tool to make the criteria clear.

The most important point is the jaws. When closed, the jaws must be at right angles to each other and form a clean square. The right angles must be cleanly worked out and must not have any curves. The jaws should be sufficiently hard. The connection between the handles and the jaws should be stable over the entire adjustment range.

With the inexpensive holding tools, the connection of the handles with the jaws has been realised by a combination of left-right threads. This leads to the threaded part being increasingly unscrewed from the jaws when they are brought together. The result: the jaws wobble and have a low grip.

It is better if the cheek piece is connected to the handle by a split pin and can thus be guided stably over the entire adjustment range. This process is also strongly influenced by the processing and the type of thread. A fine thread enables a more precise feed.

A further quality criterion is the material and the design of the basic body. With tools made of zinc die-cast, care must be taken to ensure that the material has no air inclusions (so-called blowholes). These blowholes considerably reduce the load limit of the winch iron and in the worst case can lead to the entire body breaking. This is especially true if the air pockets occur in places that are subject to the highest load.

Unfortunately, the quality of the die-casting cannot be seen from the outside. But if you discover small holes or unclean areas on the body, it could indicate a bad casting. What you can see, however, is the geometry of the basic body.

Finally, we would also like to draw attention to a point that is becoming increasingly important: it is about environmental protection and therefore about the materials used. Hammerblow lacquer and chrome-plated handles can be found on almost all tools today. You do not have to be a chemist to realise that these processes pollute the environment. There are also more environmentally friendly products on the market that have done without them.