What is the tolerance range of precision screws?
What is the tolerance range of precision screws?
The main categories of screws include ordinary screws, machine screws, self-tapping screws and expansion screws. Cap screws used to be limited to full-thread fasteners. Hex cap screw and Hex bolt Hex bolt As the name suggests, it is a male threaded fastener with a hexagonal head, designed to be turned with a wrench. According to the ASME B18.2.1 standard, the head height and shank length tolerance of the hexagon head screw (Hex cap screw) is smaller than that of the general hex bolt (Hex bolt), so the ASME B18.2.1 hexagon screw is suitable for installation in all hexagon bolts that can be used. places, also including places where the large hex bolts are too large to be used. Socket cap screw (also known as socket head screw or) is a screw with a hexagonal inner hole on the head, which can be tightened or loosened only after a hexagonal ruler (hex key, Allen wrench or Allen key) is inserted into the inner hole. The most commonly used hexagon socket head screws are cylindrical head screws with a head diameter of about 1.5 times the main diameter of the thread (1960 series). Countersunk head cap screw. The counterbore design allows the screw head to rotate without being exposed on the surface of the fixed object, so it is mostly used in places where the surface is small and traditional wrenches are inconvenient to use. Machine screw is generally a screw (4#~12#) with a diameter less than ¼ inches, usually full teeth and rotated by a screwdriver, such as slotted, cross or hexagon socket. Wood screws, machine screws; but can be divided into many categories according to different uses; machine screws can be divided into longitudinal tightening screws and horizontal expansion screws; according to the thread can also be divided into: A: Triangular thread (60 degrees ) : combined/locked/expanded B: triangular thread for pipe (55 degrees): combined/locked 3) C: trapezoidal thread (30 or 29 degrees): power transmission D: square thread (90 degrees): power transmission stainless steel screw Stainless Steel Anti-Drop ScrewsStainless Steel Anti-Drop Screws Machine (Treadmill) Screws And Shafts For Motorcycle Or Bicycle Needle Car Screws, Axes Screws And Shafts For Sewing Macing Socket Set Screws Stainless Steel Wide Thread ScrewsStainless Steel Coarse Thread Screws Stainless Steel High-Low Thread Screws Stainless Steel Machine Screws Stainless Steel Self Drilling Screws Stainless Steel Self Tapping Screws Stainless Steel Self Tapping Screws Stainless Steel Thread Cutting Screws Stainless Steel Triangle Stainless Steel Tri-Lobular Thread Screws Model Description P refers to the head type is PAN head; A refers to the pointed tail teeth, B refers to the flat tail teeth, namely PA round head pointed steel teeth, PB round head flat mouth steel teeth. Self-tapping type: ◆Round head self-tapping screw PA ◆Round head flat tail self-tapping screw PB ◆Round head cutting tail self-tapping screw PT ◆Round head belt self-tapping screw PWA ◆Round head belt and flat tail self-tapping PWB ◆Round head belt Jiecut tail self-tapping PWT ◆Countersunk head self-tapping screw KA ◆Countersunk head flat tail self-tapping screw KB ◆Countersunk head cut-tail self-tapping screw KT ◆Semi-countersunk head self-tapping screw OA ◆Big head self-tapping screw BA ◆Big head flat tail self-tapping screw BB ◆Large flat head self-tapping screw TA ◆Large flat head flat tail self-tapping screw TB ◆Large flat head cutting tail self-tapping screw TT ◆Thin head self-tapping screw CA ◆Thin head flat tail self-tapping screw CB ◆Cup head hexagon socket self-tapping HA ◆Drywall/Wallboard/Fiber Nails Machine Wires: ◆Round Head Machine Screw PM ◆Round Head Machine Screw PWM ◆Large Flat Head Machine Screw TM ◆Countersunk Head Machine Screw KM ◆Half Countersunk Head machine screw OM ◆Large head machine screw BM ◆Thin head machine screw CM ◆Cup head machine screw HM
Generally, the T-bolt structure is common, and its blank shape can be completed at one time on a multi-station cold heading machine. But for T-bolts with relatively rare structures, (for example: the intersection of ¢14x42 cylinder (head) + ¢12 cylinder, the two cylinders form a 90° intersection) due to the special structure, the head Cold forming is difficult, and the traditional processing route is: die casting blank → deburring → turning processing → grinding blank diameter → wire rolling → heat treatment → surface treatment → finished product packaging.
At present, machinery and equipment have gradually become the main force of work production. Many equipment require frequent maintenance and even replacement of parts during use. During the process of maintenance and replacement, it is inevitable to encounter the problem of screw disassembly and assembly. In the process of disassembly and assembly, it is almost necessary to cooperate with both hands, or because the thread is too long, installation and disassembly are very cumbersome. Especially in the butt installation of flanges, bolts and nuts are used for clamping and fixing at this stage. During use, two hands are required to hold a board, a fixed screw, and a screw nut. This is to prevent the nut from During the turning process, the screw also rotates. When screwing, the wrench should be taken down without interruption, re-selected a good position, and then screw the screw forcefully again, and repeated several times before the screw can be unscrewed. Time and labor costs for maintenance are wasted. At present, there is no screw that is easy to install and remove.
Alloy Steel Nuts Hexagon Nuts (GB6170/DIN934, GB6175), Flange Nuts (GB6177/DIN6923) Round Nuts (GB812), Small Round Nuts (GB810), American Square Nuts, American Hex Nuts (NI/MEB18.2.2), Heavy Duty Nuts (Metric, US). Specifications: 5/16-4. Nut Specifications Nut specification table is to unify all kinds of nuts in detail, and use the table to subdivide some specifications of nuts. There are many types of nuts, and there are nuts of different materials. Each type of nut has different specifications, and each type of screw also has its mechanical properties and functions.
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