Types and applicable occasions of non-standard screws:

(1) Embedded screws are mainly used for suspending and fixing air-conditioning pipes, water pipes, electric pipes, ceilings, etc.
(2) Torsion flat-head non-standard screws can be used on cement concrete, brick walls and hollow bricks, etc., for fixing sanitary equipment.
(3) Internally forced non-standard screws with internal teeth are used for fixing marbles, water pipes, electric pipes and angle irons.
(4) Sleeve-type non-standard screws are mainly used for fixing soundproof walls and sanitary equipment.
(5) Externally forced internal thread non-standard screws, mainly used for hanging and piping of water pipes, electric pipes, and air conditioners, as well as fixing various angle irons and section steels.
(6) Non-standard screws for torsion casing are used to fix lighting, light steel dragon skeletons and sanitary equipment.
(7) Hollow non-standard screws, suitable for fixing door frames, cabinet frames, bathroom accessories and wall decorations.

When using non-standard screws, you must first use an electric impact drill (hammer) to drill the holes of the corresponding size on the fixed body, and then put the bolts and expansion tubes into the holes, and tighten the nuts to make the bolts, expansion tubes, installation parts and the fixed body Between swelling and tightening become one. After tightening, it will expand. The bolt has a large end. The bolt is covered with a round tube slightly larger than the diameter of the bolt. There are several openings at the end. When the bolt is tightened, the large end of the bolt is brought into the open tube. Make the pipe bigger to achieve the purpose of expansion, and then fix the bolt on the ground or wall to achieve the purpose of rooting.