A hammer is a tool that strikes an object to make it move or deform. A hammer consists of a hammer head and a handle. According to the material of the hammer, the hammer is divided into steel hammer and soft hammer. Hammer, plastic hammer and rubber hammer commonly used in automobile maintenance. Plastic hammers and rubber hammers are often used in engine overhaul. For example, when removing and installing the cylinder head, knock the cylinder head so as not to deform it. The main function of hammer is also called hammer or hand hammer, which belongs to hammering tools. It is mainly used for hammering tools such as chiseling and punching, or hammering workpieces to deform, displace and vibrate them, so as to achieve the purpose of correction and shaping.

Hammer head can be divided into round hammer, square hammer and sheet metal hammer. According to the shape of hammer, it can be divided into hammer and soft hammer. It depends on the material of the hammer. The specifications of the hammer are generally expressed by mass, such as 0.25kg, 0.5kg and lkg.

Types and functions of hammers 1) hammers

Hammer materials are mostly forged from carbon tool steel, and hammers commonly used in automobile maintenance include round hammers, square hammers and sheet metal hammers.

Round head hammer is the most commonly used hammer. It has a flat head at one end and a round head at the other. Flat head is used to hammer punches, yokes and other tools, while round head is used to tighten and hammer washers. Square hammer, also known as sledgehammer, is made of high carbon steel, which is mainly used for heavy blows and is not commonly used in automobile maintenance. The hammer head of the sheet metal hammer is wedge-shaped, which is mainly used to shape the corner where the sheet metal or round hammer is inconvenient to approach. It is forbidden to directly hit the mating surface and wear parts with a hammer, because the hammer will damage parts made of low hardness materials, such as aluminum shell or cylinder head.

2) Soft-faced hammer Soft-faced hammer is mainly used to hit parts that are not allowed to leave traces or are easily damaged.

According to the different materials used in soft hammer, it can be divided into rubber hammer, plastic hammer and wooden hammer.

Many soft-faced hammers contain metals such as lead or copper to increase inertia.

Soft hammer is mainly used in automobile assembly process, which is used to knock parts to form better cooperation between parts.

How to use the hammer 1) Selection of the handle of the hammer Most hammers have been equipped with the handle at the time of purchase. If you choose to install the handle yourself, pay attention to the thickness of the handle and the size of the hammer. The center line of the hammer head should be perpendicular to the center line of the hammer handle, and the direction of the largest elliptical diameter of the hammer handle should be consistent with the direction of the center line of the hammer head.

2) the grip of the hammer

Grip method: Hold the hammer handle with the five fingers of the right hand, put the thumb on the index finger, the tiger's mouth points in the direction of the hammer head, and the end of the wooden handle is exposed15 ~ 30 mm. During the swing of the hammer, the five fingers always hold the hammer handle tightly. Loose grip method: when swinging the hammer, only the thumb and forefinger always hold the hammer handle, and the other three fingers are relaxed in the order of little finger, ring finger and middle finger; When they are hit, they are folded and clenched in the opposite order. The advantage of this method is that the hand is not easy to get tired and the knocking force is relatively large. Don't hold the hammer handle too close to the hammer head, try to be close to the handle end, because it will be more labor-saving and flexible to knock.

3) hammering

In practice, according to the different requirements of the machined workpiece for hammering force, there are three ways to hammer.

Wrist swing: Only use the wrist to move the hammer when swinging the hammer, so the hammer force is small. Hammer holding method is generally suitable for machining operations with small hammering force. Elbow swing: when swinging a hammer, the wrist and elbow swing together to complete the hammering action, with great hammering force. Hold the hammer loosely, which is a common method of swinging the hammer. Pendulum: When pendulum, wrist, elbow and arm move together, and the hammer will pass behind the ear, with the greatest hammering force. It is suitable for work that requires a large hammering force. This method is laborious and difficult to master, but once you master the swing arm, the other two methods will be easy to master.

When using a hammer, eyes should be fixed on the working object, and the hammer surface should be parallel to the working surface, so as to ensure that the hammer surface hits the working object smoothly without being skewed, avoid damaging the surface shape of the working object, and prevent personal injury and equipment damage caused by the skew of the hammer.

Precautions for the use of the hammer Before using it, make sure that the surface and handle of the hammer are free of oil stains, so as to avoid the hammer slipping from the hand during use, causing injury and damage.

Before use, check whether the handle is firmly installed and whether there are cracks, so as to prevent the hammer from falling off and causing accidents. If the hammer is loose, you can plug it with a wedge; If the handle is broken or broken, it should be replaced with a new handle immediately, and it is forbidden to continue using it.

It is very dangerous to use a hammer with damaged appearance. When knocking, the metal on the hammer may fly out, causing an accident.

Be sure to wear safety glasses when using a hammer to beat tools such as baskets and punches.

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