What Is a Striking Wrench?
A striking wrench is a type of wrench that can apply strong force by striking the handle with a hammer.
As bolts and nuts become larger, it becomes difficult to tighten them satisfactorily by manpower. This wrench is used for removing rusted nuts and nuts that cannot be moved by an ordinary wrench, or for parts that require retightening.
The striking wrench is designed to be struck with a hammer at the end of the handle while pulling a rope through the hole at the end of the handle. Tightening can be increased by striking.
On the other hand, it is used to loosen nuts that have become hardened due to rust. There are other tools of the striking type, such as the striking face ring wrench. Incidentally, “wrench” and “spanner” basically mean the same thing.
Uses of Striking Wrenches
Striking wrenches and striking face ring wrenches are used in situations that require a large amount of force. Therefore, they are frequently used for “fastening work” of bolts and nuts in various factories.
They are also useful for tightening bolts and nuts with strong force in places where they tend to loosen due to continuous or intermittent vibration, such as trains and factories. It is also useful for bolts that have deteriorated over time or have been distorted due to accidents or disasters.
However, since strong one-way force is applied, it is inappropriate if the other material is weak or the size is different, as this can lead to damage to the part.
How to Select Striking Wrenches
- Spanner type or face ring wrench type
Both can be purchased, but since they strike with very strong force, specifications that keep them properly fixed are preferable. In this respect, the face ring wrench is very safe because it is firmly fitted to the target part and the hand is not placed on the wrench part. - Two-face width (opposite side dimension)
As with general wrenches and spanners, it is necessary to select a size that matches the target bolt or nut. Generally, you will choose from a range of 30 to 145 mm. - Offset
Offset is another common choice, with some having one step at 45° and others having two steps, such as 45° + 6°. This is applicable when the workability is poor with a straight-type wrench. - Striking part
Generally, the thickness is the same as that of the spanner/wrench section. On the other hand, if you have difficulty in narrowing down the target of a blow or if you need to strike with a lot of force, it is recommended to select a box-shaped blow section to reduce the possibility of making a mistake in striking. - Material
Chrome vanadium steel is the toughest wrench with a hardness that takes impact into account and is 2.5 times stronger than that of a JIS strong grade wrench.
High carbon alloy steel is harder and more brittle than stainless steel, but has the advantage of being inexpensive and easy to obtain. - Surface treatment: cationic electrodeposition coating
This coating is used to suppress the formation of rust. Striking wrenches are prone to induce rust if made of ordinary materials because the striking wrenches are subject to significant deterioration and wear and tear. If they become even more brittle, they will need to be replaced. From the painting aspect, a tool with endurance would be preferable.