The commonly used torque wrenches include manual torque wrench, electric torque wrench, pneumatic torque wrench and hydraulic torque wrench. I have written many articles about hydraulic wrench before, which will not be repeated here. Now I will discuss the characteristics and functions of manual torque wrench, electric torque wrench and pneumatic torque wrench

1、机械式扭力扳手：在使用中如果力矩达到所设定力矩值后就会有“咔咔”类似机械碰撞报警的声音，此时扳手就不能再进行工作了，防止出现过力现象。

1. Mechanical torque wrench: in use, if the torque reaches the set torque value, there will be a "click" sound similar to mechanical collision alarm. At this time, the wrench can no longer work to prevent excessive force.

2、数显式或者指针式扭力扳手：这两种是在机械式扭力扳手上加装数显或指针式力矩表，将作用力矩可视化。

2. Digital display or pointer torque wrench: these two types are to add a digital display or pointer torque meter on the mechanical torque wrench to visualize the acting torque.

3、自动滑转式扭力扳手：这种扭力扳手工作原理是达到设定力矩至后自动卸力，起到过载保护的作用。

3. Automatic sliding torque wrench: the working principle of this torque wrench is to automatically release the force after reaching the set torque and play the role of overload protection.

以上三种手动扭力式扳手中，属机械式扭力扳手流通较为广泛，其因为成本低、价格便宜，市面上使用较多。

Among the above three manual torque wrenches, mechanical torque wrenches are widely used in the market because of their low cost and low price.

二、电动扭力扳手：是指可以在扳手上面设定扭矩值的电动扳手，是目前流通更广、使用频率较高的一款电动扳手。其按使用功能又分为电流式电动扳手和带动态扭矩传感器式电动扳手两种。

2、 Electric torque wrench: it refers to the electric wrench that can set the torque value on the wrench. It is the most widely circulated and frequently used electric wrench at present. According to the use function, it is divided into current electric wrench and electric wrench with dynamic torque sensor.

1、电流式电动扳手：这种电动扭力扳手是根据电机拧紧过程中电流值的变化来判断扭力值的，一旦达到设定的扭矩值，电机就自动停机停止工作。按使用范围不同分为直柄式电动扭矩扳手和弯柄式电动扭矩扳手。

1. Current electric wrench: this electric torque wrench judges the torque value according to the change of current value during motor tightening. Once the set torque value is reached, the motor will automatically stop working. It can be divided into straight handle electric torque wrench and curved handle electric torque wrench according to the scope of use.

2、带扭矩传感器式电动扳手：这种带传感器的扳手是在减速箱体上安装有扭矩传感器，可以监测到扳手扭力值变化，一定达到预定的扭矩值，电机就自动停机工作。

2. Electric wrench with torque sensor: This wrench with sensor is equipped with torque sensor on the reduction box, which can monitor the change of wrench torque value. When the predetermined torque value is reached, the motor will stop working automatically.

电动扭力扳手的使用范围较为广泛，而其所具有扭矩精度高、使用范围广、故障率低、使用寿命长的特性，在很多领域得以发挥作用。

Electric torque wrench is widely used, and it has the characteristics of high torque precision, wide application range, low failure rate and long service life, which can play a role in many fields.

三、气动扭力扳手：这种扳手工作原理是压缩气体作为气源，设定气压后通过气动三联件带动扳手中的启动马达来驱动齿轮对螺栓进行拧紧，主要有油压脉冲式、离合器式、动态扭矩传感器式。

3、 Pneumatic torque wrench: the working principle of this wrench is to use compressed gas as the air source. After setting the air pressure, the pneumatic triplet drives the starting motor in the wrench to drive the gear to tighten the bolts, mainly including oil pressure pulse type, clutch type and dynamic torque sensor type.

1、油压脉冲式和离合器式：这两种气动扳手是通过扭矩值达到设定值后自动断气来避免过力的。

1. Oil pressure pulse type and clutch type: these two pneumatic wrenches automatically cut off the air after the torque value reaches the set value to avoid excessive force.

2、扭矩传感器式：当扭矩值达到设定扭矩值后，控制器会控制电磁阀断气，扳手停止工作，此时将无法再用力，从而避免过力。

2. Torque sensor type: when the torque value reaches the set torque value, the controller will control the solenoid valve to cut off the air and the wrench will stop working. At this time, it will not be able to exert any more force, so as to avoid excessive force.

气动扭力扳手中，油压脉冲式因其无反作用力而受到很多人的青睐，但不适合用来打软连接螺栓。

Among pneumatic torque wrenches, oil pressure pulse type is favored by many people because of its no reaction force, but it is not suitable for soft connecting bolts.