Flange nut product common sense summary flange nut spec […]
Flange nut product common sense summary flange nut specification parameter collection In the hardware and electromechanical industry, nuts and other standard parts occupy a very important position. As a kind of important standard product, flange nut is sold in the hardware wholesale market and hardware accessories city. However, for its common sense cognition, there are still many people who do not understand the specifications and parameters. Today we bring you a summary of common knowledge of flange nut products, a collection of flange nut specifications and so on. The first part: general knowledge of flange nut products According to China's hardware machine grid information: flange nuts, also known as with pad nuts, flower tooth nuts, hex flange nuts, flange nuts and so on. Mostly used on pipes that are connected or that require additional nut contact surfaces. GB code GB6177-2000 Product parameters Chinese name: Flange nut Hanyu Pinyin: fa lan luo mu Material: A3 low carbon steel 35K high speed steel wire 45# steel 40CR 35Crmoa Hardness level: 4 level 5 level 6 level 8 level 10 level 12 level Surface treatment: generally divided into zinc plating, white zinc plating, black zinc plating, and generally cold electroplated zinc! Main specifications: M5 M6 M8 M10 M12 M16 M20 (M20 and above specifications and M14 M18 flange nuts are not commonly used) Function mode Hardware and building materials industry analysis, flange nuts and general hex nuts size and thread specifications are basically the same, but only Compared with the hex nut, it is a one-piece gasket and nut, and has anti-slip teeth on the underside, which increases the surface contact between the nut and the workpiece, and is stronger and stronger than the combination of the common nut and washer. Bigger. This type of nut is generally available in the home improvement building materials market.
Hardware and electromechanical industry believes that the common flange nut specifications are generally below M20, because most flange nuts are used on pipes and flanges, so they are constrained by the workpiece. The flange nut specifications are compared with the nuts. slightly less. Some of the flange nuts above M20 are mostly flat flanges, that is, there are no tooth marks on the flange surface. Most of these nuts are used in some special equipment and special places, and the general sales manufacturers are not in stock. Product defects Hardware and electromechanical industry believes that due to the small size of the flange nut, irregular shape, and some need thread matching, hot dip galvanizing has some obvious defects. 1. It is difficult to screw the screw after plating. After the hot dip galvanizing, the residual zinc remains in the thread and is not easily removed, and the thickness of the zinc layer is uneven, which affects the fitting of the screw. It is stipulated in GB/T13912-1992 "Technical Requirements for Hot Dip Galvanizing Layer of Metal Covered Steel Products" and GB/T2314-1997 "General Technical Requirements for Electric Power Fittings"; the external thread of fasteners shall be in accordance with GB196 before hot dip plating.
Standards are specified for machining or tanning, while internal threads can be machined before or after hot dip coating. However, in practical applications, customers often require galvanized layers for both internal and external threads. Therefore, various measures have been taken to solve the problem of hot dip galvanizing of threaded fittings. Such as the backlash after the screwing of the screw; reserved a large fit clearance; centrifugation and other methods. Experts in the hardware analysis, back attack easily destroys the plating of the thread part, and even exposes the steel substrate, causing the fastener to rust. Deliberately over-range to increase the nut diameter or reserve clearance, it is easy to reduce the mating strength, which is not allowed for high-strength fit. 2, hot dip galvanizing operation temperature is high, will reduce the mechanical strength of high-strength flange nuts.
The strength of some threads of 8.8 bolts after hot dip galvanizing is lower than the standard requirements; the strength of bolts above 9.8 after hot dip galvanizing is basically unable to meet the requirements. 3. The working environment is poor and the pollution is serious. The hot dip galvanizing process of the fastener is carried out at a high temperature. The solvent drying and the zinc to be immersed into the pool will cause strong irritating hydrogen chloride gas; the zinc pool will be at a high temperature for a long time, and zinc vapor will be generated on the surface of the zinc pool. The atmosphere of the entire working environment is bad. Although there are many defects in hot-dip galvanizing of fasteners, the hot-dip galvanized coating has good plating thickness, good bonding strength and long-term anti-corrosion effect.
It has always been respected in the power, communications, and transportation sectors. With the development of China's electric power and transportation, the development of hot-dip galvanizing of flange nuts will be promoted; therefore, the development of automatic centrifugal boring equipment, improvement of hot-dip galvanizing process of fasteners, and improvement of the quality of hot-dip galvanized coatings of fasteners are Very important. The hardware market needs such power. Part II: Specifications B/T9113 flange standard GB/T 9113.1-2000 PN1.0MPa (10bar) protruding integral steel pipe flange nominal through DN connection size sealing surface flange thickness C outside the flange neck flange Through D bolt hole Center circle diameter K Bolt aperture L Bolt df NR Number n Thread size 10 90 60 14 4 M12 41 2 14 28 3 15 95 65 14 4 M12 46 2 14 32 3 20 105 75 14 4 M12 56 2 16 40 4 25 115 85 14 4 M12 65 2 16 50 4 32 140 100 18 4 M16 76 2 18 60 5 40 150 110 18 4 M16 84 2 18 70 5 50 165 125 18 4 M16 99 2 20 84 6 65 185 145 18 4 M16 118 2 20 104 6 80 200 160 18 8 M16 132 2 20 120 6 100 220 180 18 8 M16 156 2 22 140 8 125 250 210 18 8 M20 184 2 22 170 8 150 285 240 18 8 M20 211 2 24 190 10 200 340 295 22 8 M20 266 2 24 246 10 250 395 350 22 12 M20 319 2 26 298 10 300 445 400 22 12 M20 370 2 26 348 10 350 505 460 22 16 M24 429 2 26 408 12 400 565 515 22 16 M24 480 2 26 456 12 450 615 565 22 20 M24 530 2 28 502 12