Buying skills for driving hydraulic wrenches

The choice of hydraulic wrench is determined by bolt size, torque requirements, and space range.
bolt size
What kind of bolts are there in general, metric or inch? For example, M36, M42, and M48 refer to metric bolts. The hexagon opposite side of the M36 nut is 55, the M42 is 65, and the M48 is 75. One type of hydraulic wrench can be selected. If the bolt specification span is too large, and the torque span is large, it is necessary to use various types of wrenches to pre-tighten these bolts.
Torque Requirements
The specification of the bolt and the strength grade of the bolt are the most critical parameters for the selection of hydraulic torque wrenches. Different bolts have different torques. The same bolt has different strength levels and different torques. The same bolt strength levels have different torques under different working conditions. For example, M36 bolts have a strength grade of 8.8 and a torque of 1764Nm; strength grades of 10.9. grades and torque of 2453Nm; strength grades of 12.9.
Spatial position of bolts and nuts
If there is no space limitation, any type of wrench can be used; the driven hydraulic wrench is more general; if the exposed thread is long after the bolt is tightened or the space above the bolt is limited, it is best to use a hollow hydraulic wrench; if the distance between the nuts is narrow , can choose hollow hydraulic wrench.
Other considerations
1) One type of hydraulic wrench can only solve several similar bolts, generally with 1-10 sockets;
2) Conditional manufacturers can use one electric pump with two wrench heads, use diagonally, which can improve efficiency and more accurate torque;
3) The hydraulic wrench must be used by a special person, kept by a special person, and maintained regularly, such as oil change, cleaning, etc.;
4) The bolt torque standard should be subject to the national standard, which is in line with China's national conditions.