The selection of stone dry hanging engineering materials should be strictly in accordance with the drawing design and comply with the requirements of the "Technical Specifications for Metal and Stone curtain wall Engineering" (JGJ133-2001), but the individual construction units choose inferior materials to reduce costs, especially the dry hanging parts and dry hanging glue. Replace national standard 304 stainless steel or 7075 aluminum alloy pendants with "stainless iron" welded head dry pendants through demagnetization, and the tensile strength of these three pendants is: national standard 304 stainless steel 530? |620MPA, 7075 aluminum gold 540? |560MPA, while the "stainless iron" is only 160? |180MPA, its strength is not up to 1/3 of stainless steel. If it is not appropriate to use it as a dry pendant, who is responsible if there is a problem? In addition, the gap between the board and the board is mostly 6MM, 8MM or 10MM, but in the installation process, because the thickness of the dry pendant is mostly 4? 5MM, in this way, the gap between the plate and the plate is adjusted by nuts, gaskets, etc., resulting in cumulative load, so hard contact, will have terrible safety consequences in the case of vibration and temperature change. For a long time in the construction process with hercules glue instead of stone dry hanging glue is also a wrong practice, Hercules glue is the glue between stone and stone with mutual bonding, it is unscientific for the bond between stone and metal, its bond strength is weaker than stone dry hanging glue many times, Moreover, it does not meet the specification requirements of the industry standard "Epoxy adhesive for dry hanging stone curtain wall" (JC887-2001).