Wed Aug 17 15:13:19 CST 2022
We use combination screws sometimes in our life, but do you know anything about combination screws?
Maybe people don't know much about screw assembly anymore. You can read the news if you want.
Combination screw is a screw with a spring pad with a flat pad through the rubbing teeth, the combination of fastening together components.And two combination screw is a screw only with a spring pad or only with a flat pad.It can also be fitted with only one of the two assembly teeth.The national standard number of combined screw is indicated by GB9074. The national standard number of the commonly used cross recessed small pan head three combination screws is GB9074.8. This. 8 means small dish head. That is often said that the head screw head size. Expressed alphabetically as PM.
Professional combination screw manufacturers, the habitual way of expression is the triple PM.The national standard of cross-recessed large PAN head combined screw is GB9074.4. Professional called the combination of large head screws. Or R-head, or B-head.That is to say, the head of the combination screw than the head of the small pan head combination screw to be larger, to be thicker.There is also a common combination of hexagonal screws, this is the cross hexagonal combination of screws. Commonly known as hexagonal combination of concave hole screws. GB 9074.13.
High Strength Hex head bolt combined screw for steel structure, mainly used for railway and highway bridge, boiler steel structure, industrial workshop, high-rise civil building, tower mast structure, crane and its steel structure need to use friction type high-strength bolt combination screw occasions.The feature is the bolt, also known as the end of the bolt more than a dodecahedron. When installation, to use a special electric wrench, its upper and lower two sleeve head, one set in the nut on the hexagonal, the other set in the hexagonal hexagonal screw on the ten-angle.When tightening, a clockwise force distance is applied to the nut, and an equal counterclockwise force distance is applied to the dodecahedron of the bolt, so that the end of the outer hexagonal screw is connected with the dodecahedron and the neck is subjected to torsional shear until the neck is sheared off, installation begins and ends.
The torsion-shear type high-strength external hexagon screw is a one-time-use screw, which can not be disassembled after installation.
