The construction of the safety project jack should ensure that the rack, screw, and plunger cannot detach from the cylinder of the base at the maximum lifting height. The rack, screw, and plunger shall not lose stability under the test loads in Table 6-10-19. When the jack is placed on a supporting surface at an angle of 60 degrees to the horizontal, and the rack, screw, and plunger are at their maximum lifting height, the center of the head is subjected to a rated load perpendicular to the horizontal for no less than 3 minutes, there shall be no plastic deformation or other abnormal phenomena in any part.

　　Appearance quality: The outer surface of the product should be sprayed with paint according to regulations. The paint should adhere firmly, the coating surface should be uniform, and the color should be consistent. There should be no obvious defects such as spots, wrinkles, bubbles, etc. Exposed machined surfaces should undergo rust prevention treatment.

　　The dynamic load test is conducted at room temperature by placing the jack on an equipment that meets the requirements of the dynamic load test. The hydraulic jack should meet the requirements of 5121 in JB2104-91 "Hydraulic Jack", and the screw jack should meet the requirements of 5121 in JB2592-91 "QL Screw Jack".

　　Static load test is conducted at room temperature using the standard method to apply a test load to the jack. The hydraulic jack should meet the requirements of 5113 in JB2104-91 "Hydraulic Jacks", and the screw jack should meet the requirements of 521 in JB2592-91 "QL Screw Jacks".

　　The operating force of the handle shall be measured at a distance of 50mm from the end of the handle under the test load of the rated lifting capacity. The force shall be perpendicular to the axis of the handle, and the measured results shall comply with the standard regulations.

　　When conducting action inspection in the no-load state during the no-load test, each operating mechanism of the jack should be flexible and reliable, without any looseness or tightness within the full range of travel, and the lifting should be stable and the limit should be reliable.

　　Other hydraulic jacks should also undergo adjustment inspection, piston rod pressure test, sealing inspection, descent inspection, and high-temperature sealing inspection before leaving the factory. The screw jack should undergo overload inspection.

　　The type test items for hydraulic jacks include volumetric efficiency inspection, inclined loading inspection, permanent deformation inspection, continuous working test, internal impurity content inspection, and high and low temperature working performance inspection; The screw jack includes static load test, inclined load test, permanent deformation test, life test, etc.