What is the tolerance range of precision screws?
What is the tolerance range of precision screws?
Building aluminum alloy formwork is a new type of building formwork, which conforms to the four sections and one environmental protection policy. It is economical, fast, high-quality and environmentally friendly. Its application is of great significance to building energy conservation and environmental protection. The aluminum template is filled with aluminum template pins. However, the pins in the prior art have low connection strength during use, which is likely to cause the hole to be repaired weakly.
In the prior art, the beams used for installing the curtain wall are mainly divided into two types: closed-cavity structure and open structure, and angle aluminum connection is mainly used for the connection between the beam and the column. As far as the beam of the closed-cavity structure is concerned, after the angle aluminum is used to connect, there are open bolts on both ends of the upper surface of the beam, and the aesthetic performance is extremely poor. As far as the beam of the open structure is concerned, in the actual connection, first fix one corner of the angle aluminum to the beam, and then connect the other corner of the angle aluminum to the column; due to the limited operating space in the beam of the open structure, the angle aluminum is not It is easy and accurate to install, and it takes a lot of time to install; and when the curtain wall panel is heavy, the beam will be twisted, causing the gusset of the opening part of the beam to fall. In addition, due to the limitation of the opening structure itself (an additional gusset or clasp), the aluminum content of the beam is relatively heavy, and the manufacturing cost is high.
rivet is a nail-shaped object used to join two parts or components with a through hole and a cap on one end. In riveting, the riveted parts are connected by their own deformation or interference. There are many types of rivets, and they are informal. Commonly used are R-type rivets, fan rivets, blind rivets, blind rivets, tree rivets, semi-circular head, flat head, semi-hollow rivets, solid rivets, countersunk head rivets, blind rivets, hollow rivets, these usually use their own deformation Connect the riveted parts. Generally less than 8 mm with cold riveting, larger than this size with hot riveting. But there are exceptions. For example, the nameplate on some locks is riveted by the interference between the rivet and the lock body hole.
Code name and standard number of inch thread commonly used abroad Mark code name country and standard number Remarks BSW standard Wyeth coarse thread series, general purpose cylindrical thread British standard BS 84 inch thread with a profile angle of 55° BSF standard Wyeth fine thread series, General Purpose Cylindrical Thread Whit.S Additional Whit.S Optional Series, General Purpose Cylindrical Thread Whit Non-standard thread with Whitworth profile UN Uniform thread of constant pitch series American standard ANSI B1.1 inch thread with 60° profile angle, with Internal and external threads with standard profile (flat or rounded at random) UNC Coarse thread unified thread UNF fine thread unified thread UNEF superfine thread unified thread UNS① Special series unified thread UNR round The uniform thread profile angle of the arc root constant pitch series is 60° inch thread, UNR, UNRC, UNRF, UNREF, UNRS with arc root are only used for external thread without internal thread UNRC arc root coarse thread Series Unified Thread UNRF Circular Root Fine Thread Series Unified Thread UNREF Circular Root Ultra Fine Thread Series Unified Thread UNRS Circular Root Special Series Unified Thread NPT② Generally used for pipe thread American standard ANSI B1.20.1 Profile angle is 60° Inch Pipe Thread NPSC Pipe Fitting Straight Pipe NPTR Pilot Connection Tapered Pipe NPSM Mechanical Connection Straight Pipe NPSL Lock Nut Straight Pipe NPSH Hose Connection Straight Pipe NPTF Dry Seal Standard Tapered Pipe Thread American Standard ANSI B1.20.3 Type I PTF-SAE SHORT Dry Seal Short Taper Pipe Thread Type II NPSF Dry Seal Standard Fuel Oil Straight Pipe Internal Thread III Type NPS1 Dry Seal Standard General Straight Pipe Internal Thread IV Type ACME③ General Purpose Trapezoid Thread American standard ANSI B1.5 Inch drive thread with 29° profile angle ① Dimensions and tolerances All diameter and pitch combinations other than the standard series are calculated using the same formula as the standard series. ② my country's 60° conical pipe thread GB/T12716-1991 is equivalent to it. ③ACME thread includes two kinds of matching trapezoidal threads, general purpose and centering, of which the general purpose thread has the same performance as the trapezoidal thread specified in my country's standard GB/T5796-1986.
The above content is uploaded by Yueluo or the Internet. If there is any copyright issue, please contact [email protected].
