What Is a Hook Spanner?
A hook spanner is a tool mainly used to tighten or loosen an adapter nut. As the name suggests, it is shaped like a hook and is used by hooking the hook spanner’s claw part into the groove of the adapter nut.
Since all you have to do is hook and turn it, it is easy and safe to tighten and loosen.
However, if the size of the hook spanner is not selected to match the size of the adapter nut, the hook spanner’s jaws may come off during operation, which could result in injury. Therefore, size selection should be done carefully.
How to Use the Hook Spanners
Hook spanners are mainly used to tighten or loosen grooved nuts called adapter nuts.
First, to use the hook spanners, select hook spanners of the appropriate size for the adapter nut, and hook the claw on the tip of the hook spanner into the groove of the adapter nut. Then, place the base of the arc called the “jaw” against the adapter nut.
Turn the handle clockwise to tighten the nut and counterclockwise to loosen it. At this time, a large force is generated by the principle of leverage, with the claw as the point of action, the jaw as the point of force, and the handle as the point of force.
How to Choose Hook Spanners
When choosing hook spanners, you must first select a size that fits the adapter nut perfectly.
If the hook spanner is too small for the adapter nut, the jaws will not go deep enough into the groove, and the hook spanner will not be able to get a good grip. Also, the hook spanners will not be able to exert sufficient force, which may result in insufficient tightening or loosening torque.
If the hook spanner is too large for the adapter nut, the jaws will be too long for the depth of the groove, resulting in shallow jaw engagement. Also, the fulcrum will hit somewhere in the arc instead of the jaw, and the hand force will not be transmitted properly. In addition, if the tightening torque becomes too large, the screw will be damaged.
As mentioned above, the size selection of the hook spanners is important for safety. Basically, it is safe as long as the arc of the hook spanners is in line with the outside diameter of the adapter nut. To work safely, make sure that the jaws are firmly hooked and in contact before applying force.