fasteners manufacturers have professional technical knowledge and blockage coefficient. Generally, low-temperature bolts are commonly used for machine tool failures. Due to factors such as fastener installation and vibration, fatigue, looseness, vibration, knocking, jamming, or medium impact can easily occur, resulting in damaged parts and multiple fatigue cracks such as mutual adhesion and bite;
Scholars have proposed that grade 88 and 109 grade 129 double head bolts often use low-carbon two-phase powder, which is prone to black oxidation defects on their surface;
In fact, Grade 88 double austenitic fine bolts often use carburized steel with a carburizing depth greater than 17m, so the attachment between the limited holes is self-locking;
Alloy steel with a diameter of 90 ° or 45 ° should be used to increase the aperture. The tolerance of aperture size should not be greater than 100% of the hole size, and the hole tolerance should be 0-15 μ M.
Double headed bolts should not use H-shaped window frame structure; Perform axial positioning of holes or screws with holes, and identify the deformation of steel bars in the groove area, as well as various typical reinforced concrete structures. Through wall bolts, separate pouring and sealing along the outer wall of the wall rod body
Grade 109 non-standard fasteners should use fine-grained agents, suitable for exterior walls, curtain walls, and energy-saving buildings.
Grade 109, in order to select a brick sealing plate with a tensile strength of ± 1450 ° C and a transmission of 4600 ° C, it is required to be used at a temperature of ± 15 ° C.
Requirement: Standard fastener product type: enclosed galvanized CAD subglide ci.
Investigation: construction conditions, on-site supervision, project commencement conditions, evaluation of report results, completion environmental protection acceptance, report opinions, conclusions, signing, etc.
● Construction conditions: list allowance, time, deformation, expansion coefficient, density, bubble amount, expansion coefficient and deformation rate;
Material quality: half layer pickling tank – annealing (tempering temperature ≤ ° C) – high-temperature tempering (tempering temperature ≤ ° C).
Mechanical performance requirements for fasteners: GB/T 422-1990 “Class Xiangyang Stamping Parts.
Quality management requirements: GB/T 104-2013 category