Screw does not loosen

Screw does not loosen

The screw is also called loose, spring screw and non-loose screw. It is a pressure rivet to obtain a rising rivet on the mounting plate, and the position of the plate and the plate is fastened by screws.

Luósī [screw] screw.

Various screw thread types A: triangular thread (60 degrees): binding/locking B: triangular thread for pipes (55 degrees): binding/locking C: trapezoidal thread (30 or 29 degrees): power transmission D: square thread (90 degrees): power transmission

The value of screws

There are many types of screws, whether it is a very small screw for glasses or a large screw for large-scale heavy power engineering. The main purpose is to form a fixed body with industrial products of high use. If the teeth cannot be tightly fastened during use, the screw head will break off if locked too hard, or the tooth pattern will not be locked tightly, which is a problem of quality accuracy. Screws are "quantity products", not hand-made works of art. In mass production, they aim to achieve high-precision and stable quality and popular prices for consumers. The accuracy of screws is usually 6g (grade 2, U.S. specification "IFI" is 2A teeth), and crude screws for construction projects are 8g (grade 3, "IFI" is 1A teeth). This book provides reference for the technical focus of the manufacturing process of hexagonal head screws and general head type small screws (iron plate screws, wood screws, machine screws).
A: Machine Screw: Machine Screw
B: Tapping Screw: Self-tapping Screw (used in metal and plastic) B- 1: Sheet Metal Tapping Screw (Iron Teeth Self-tapping Screw) B- 2: Plastic Tapping Screw (Plastic, Self-tapping Screw) C: Wooden Screw: Woodworking Screw D: Drywall Screw: Cement Wall Screw E: Self Drilling Screws Stainless Steel Tail Drill Screw (Screw Drill Screw) Composite Material

This product is suitable for 1 stainless steel plate, metal steel plate, galvanized steel plate, engineering installation. 2 metal curtain wall metal light compartment and other indoor and outdoor installation. 3 general angle steel, channel steel, iron plate and other metal materials combined installation. 4, car box, container box, shipbuilding, refrigeration equipment and other assembly projects.

Features of this product: 1. Drilling and tapping, locking once completed, strong binding force. 2. Save construction time and improve work efficiency. E-2: STAINLESS Self Drilling Screws Composite Drill Tail Screws E-1: STEEL SELF DRILLING SCREWS Stainless Steel Drill Tail Screws
Edit common screw materials in this paragraph
a.Low Carbon Steel: Carbon steel Carbon steel is divided into low carbon steel, medium carbon steel, high carbon steel and alloy steel. B. SS-304 : Stainless Steel 304 and 316 belong to stainless steel c. SS-302: Stainless Steel 302: good structural toughness d. Aluminum 5052: aluminum alloy 5052 d. Brass: brass e. Bronze: bronze f. UNS C11000 Copper: antimony copper
 

Common Screw Specifications and Marking
A: Metric Screw Screw
B: U.S. gauge screw C: English screw A: metric mechanical screw: Metric Ex: M3 x 6 - P B : M3 mechanical screw, 6mm long, cross, round flat head, black plated. Finish Code: appearance processing specification Head Code: head exterior Thread Code screw model Drive Code: head section, feature model Length Code: screw length (mm) A- 1: Thread Code: screw type Metric screws directly indicate the screw type with the outer diameter of the screw, such as M3, I .e. the outer diameter of the screw is 3.00mm; M4 means the outer diameter of the screw is 4.00mm. metric thread size x pitch: note: metric screws are located behind the screw type, and sometimes the screw pitch is indicated. for example, m3 x 0.5, m4x0.70, m5x0.8, m6x1. however, due to standard specifications, it is usually not mentioned. a -2: length: length: metric screws, directly indicating the length of the screw, the unit is mm. The total length of the screw is indicated, only the length below the head is calculated, excluding the height of the head. Except for flat head screws, the total length of the screw is indicated with the height of the head. A- 3: Drive Code/head split groove, feature.
 

General common specifications
A. Slotted: one word (Minus) B. Phillips: cross (Plus) various common screws (20 sheets) c. Phil-Slot: one word/cross d. Hex Scoket: hexagon socket e. One Way: one-way (locked in only, not withdrawn) A- 4: Head Code/head shape. a. Flat: flat head (locked in, top flush with working part) B. Oval: color slider, o head, semi-countersunk head c. Round: round head d. Pan: round flat head e. Truss: great round flat head f. Hex: hexagonal head. A- 5: Finish Code/appearance treatment. metric self-tapping screw: directly marked with Tapping Type. Ex: M3 x 6 -PPB, Tapping Type: M3 self-tapping screw, 6mm long, cross, round flat head, black plating. Generally, the product is identified or marked, and then judged as Sheet Metal or plastic parts. * * * teeth are the number of teeth per inch. * * *
 

Screw length
U.S. gauge screw length must be converted to metric mm size. Conversion formula: (Length Code / 32) x 25.40 = metric length mm B- 3, B- 4,B-5: marking method is the same as metric.
Edit this paragraph inch screw
C- 1: Thread Code: The denominator is 8 for marking, and then the numerator number is directly called. Ex: 1/8 x 0.50-PPB: 1 split screw x 0.50 "long, PPB Ex: 5/16 x 0.50-PPB = 2.5/8 x 0.50-PPB: 2 split screw x 0.50" long, PPB Ex: 5/32 x 0.50-PPB = 1.25/8 x 0.50-PPB: 1 minute 2mm screw x 0.50 "long, PPB Ex: 1/4 x 0.50-PPB = 2/8 x 0.50-PPB: 2mm screw x 0.50" long, PPB note: sometimes coarse teeth or fine teeth are marked. UNF: fine teeth: commonly used in electronics industry. UNC: coarse teeth: commonly used in heavy mechanical structures. Ex: 3/8 x 0.50 ,UNF -PPB: 3 fine tooth screws x 0.50 "long, PPB. C- 2: Length Code: marked as inches, which must be multiplied by 25.40 to convert to mm. with a buckle gauge, it is metric thread that matches metric tooth profile and English thread. You can also use a caliper to measure the outer diameter of the thread, and the pitch. Metric thread outer diameter is in millimeters, such as 6,8,10,12,18,20mm, etc. Pitch is also in millimeters, such as 0.5,0.75,1,1.5,2,3, etc. Imperial thread outer diameter is in inches (each inch equals 25.4mm), such as 3/16,5/8,1/4,1/2, wait, so use a metric caliper to measure the outer diameter reading often with irregular decimals. The inch pitch is expressed in terms of how many teeth per inch. Set the caliper at 25.4mm, align one ulnar tip with the thread tip, and the other ulnar tip, if aligned with the thread tip, is an inch thread, if the thread tip is not aligned, it should be a metric thread. When measuring the pitch, it is best to print the tip of the thread on the white chalk, which is clear and easy to measure. The metric pitch should be measured for a length, such as 10,15,20, mm, etc., count how many teeth are contained, and calculate the pitch. The thread specification specified in inches is English thread, such as G1 ". Thread specifications specified in metric units of millimetres are metric threads. For example: M30. The imperial system is determined by how many teeth are within an inch (24.5cm), usually at a 55-degree angle. The metric system is the pitch determined by the distance between the two cusps, which is generally a 60-degree angle anchor screw: a screw used to fasten the machine on the ground. Also called anchor bolts. The difference between English screws and American screws is difficult to distinguish by visual inspection. The difference between English screws and American screws is that the tooth rubbing angle of English screws is 55 degrees, while that of American screws is 60 degrees. These two standard screws can be used in most cases, but 1/2 size screws are not allowed, because the standard thread of English 1/2 is 1/2-12 teeth, the American system is 1/2-13 teeth.
 

Screw related in English
Machine (step) car screws, axis Screws And Shafts For Motorcycle Or Bicycle sewing screws, axis Screws And Shafts For Sewing Maching stop screws Socket Set Screws Stainless Steel Wide Screw Stainless Steel Coarse Thread Screws Stainless Steel Cutting High and Low Screw Stainless Steel High-Low Screws Stainless Steel Screws Stainless Steel Screws Stainless Steel Drilling Screws Screw Self-Stainless Steel Screw Screw Screw Self-Steel Screw Screw Screw Steel Screw Screw Self-Steel Screw Screw Screw Screw Screw Screw Screw Screw Screw Screw Screw Screw Screw Screw Screw Screw Screw Screw Screw Screw Screw Screw Screw Screw Screw Screw Screw Screw Screw thread Cutting Screws Stainless Steel Triangle Screw Stainless Steel Tri-Lobular Thread Screws Screw Marking Thread Marking Format: thread code-thread tolerance zone code (middle diameter, top diameter)-screwing length l) tolerance zone code is represented by numbers and letters (capital letters for internal threads and lowercase letters for external threads), such as 7H,6g, etc. It should be specially pointed out that 7H,6g, etc. represent thread tolerance, while H7,g6 represent cylinder tolerance code. 2) The screwing length is specified as short (represented by S), medium (represented by N) and long (represented by L). Under normal circumstances, the thread screwing length is not marked, and the thread tolerance zone is determined by the medium screwing length (N). If necessary, add the screwing length code S or L, such as "M20-5g6g-L". In case of special needs, the value of the screwing length can be indicated, such as "M20-5g6g-30". Common thread common coarse thread: feature code M + nominal diameter + rotation direction + thread tolerance zone code (middle diameter, top diameter)-screwing length common fine thread: feature code M + nominal diameter * pitch + rotation direction + thread tolerance zone code (middle diameter, top diameter)-screwing length right-handed thread is omitted without note, left-handed thread is indicated by "LH. M 16-5g6g means coarse common thread, nominal diameter 16, right-handed, thread tolerance zone middle diameter 5g, large diameter 6g, screwing length is considered as medium length. M16 × 1 LH-6G represents fine tooth common thread, with nominal diameter of 16, pitch of 1, left-handed, the middle diameter and major diameter of the thread tolerance zone are both 6G, and the screwing length is considered as medium length. The marking format of pipe thread is: feature code (G for cylindrical pipe thread and NPT for conical pipe thread) + size code + tolerance grade code + rotation G1A--LH for inch non-threaded sealed pipe thread, size code 1in, right-hand, tolerance grade A. Rcl/2 indicates inch threaded seal taper pipe thread, size code 1/2in, right hand.
 

English description in screw model
P is the finger type and PAN head; A is the fingertip tail tooth, B refers to the flat tail tooth, I .e. PA round head pointed mouth steel tooth, PB round head flat mouth steel tooth. Self-tapping class: ◆ Round Head Self-tapping Screw PA ◆ Round Head Flat Tail Self-tapping Screw PB ◆ Round Head Cut Tail Self-tapping Screw PT ◆ Round Head with Intermediate Tail Self-tapping Screw PWA ◆ Round Head with Intermediate Tail Self-tapping PWB ◆ Round Head with Intermediate Tail Self-tapping Screw KA ◆ Countersunk Head Flat Tail Self-tapping Screw KB ◆ Countersunk Head Cut Tail Self-tapping Screw KT ◆ Large Head Self-tapping Screw OA ◆ Large Head Self-tapping Screw BA large flat head flat tail self-tapping screw TB Large flat head cut tail self-tapping screw TT Thin head flat tail self-tapping screw CA Thin head flat tail self-tapping screw CB Cup head hexagon socket self-tapping HA Drywall nail/wallboard nail/fiber nail machine wire type ::: Round head machine screw PM Round head with machine tooth screw PWM Large flat head machine tooth screw TM Countersunk machine tooth KM flat head screw BM Head screw OM cup head machine bolt HM
 

Screw Classification
The main categories include ordinary screws, self-tapping screws and expansion screws. Cap screw used to be limited to full-tooth fasteners, but this is not the standard use now. Hexagon head screws Hex cap screw and large hexagon bolts Hex bolt, as the name implies, are externally threaded fasteners with a hexagonal head, designed to be turned with a wrench. According to the ASME B18.2.1 standard, the head height and rod length tolerance of the hexagon head screw (Hex bolt) is smaller than that of the general large hexagon bolt (Hex bolt), so the ASME B18.2.1 hexagon screw is suitable for installation in all the places where the hexagon bolt can be used, and also includes the place where the large hexagon bolt is too large to be used. Socket cap screw, also known as socket screw or Allen bolt (Allen bolt), is a screw with a hexagonal hole in the head, which can be tightened or loosened only after the hex key (Allen wrench or Allen key) is inserted into the hole. The most commonly used hexagon socket head screws are cylinder head screws with a head diameter of about 1.5 times the main diameter of the thread (1960 series). Other head types include semicircular head screws (bottom head cap screw) that make the surface beautiful and flat head screws (Countersunk head cap screw) that are suitable for tapered screw holes. The counterbore design allows the screw head to rotate without being exposed on the surface of the fixed object, so it is mostly used where the surface is small and the traditional wrench is inconvenient to use. Machine screw Machine screw is generally a screw (4#~ 12#) with a diameter of less than ¼ inch, usually full teeth and rotated by a screwdriver, such as slotted, cross or hexagon socket.

The value of screws Screws Screws are indispensable industrial necessities in daily life: such as very small screws used in cameras, glasses, clocks, electronics, etc.; general screws for televisions, electrical products, musical instruments, furniture, etc.; as for engineering, construction, and bridges Large screws and nuts are used; transportation appliances, airplanes, trams, automobiles, etc. are used for both large and small screws. Screws have an important role in industry, and as long as there is industry on Earth, the function of screws is always important. There are many types of screws, whether it is a very small screw for glasses or a large screw for large-scale heavy power engineering. The main purpose is to form a fixed body with industrial products of high use. If the teeth cannot be tightly fastened during use, the screw head will break off if locked too hard, or the tooth pattern will not be locked tightly, which is a problem of quality accuracy. Screws are "quantity products", not hand-made works of art. In mass production, they aim to achieve high-precision and stable quality and popular prices for consumers. The accuracy of screws is usually 6g (grade 2, U.S. specification "IFI" is 2A teeth), and crude screws for construction projects are 1g (grade 3, "IFI" is 1A teeth).
skillful use of screws
1. First, remove the sludge on the surface of the broken screw and use the central spear to kill the central spear of the section. Then use an electric drill to install a drill bit with a diameter of 6-8mm to drill the hole in the central spear of the section. Pay attention to the hole. After the hole is drilled, remove the small drill bit, replace it with a drill bit with a diameter of 16mm, and continue to expand and drill the hole of the broken bolt.

2. Take the welding rod with a diameter of less than 3.2mm and use small and medium current to surfacing from inside to outside in the hole of the broken bolt. Take half of the whole length of the broken bolt at the beginning of surfacing welding. Do not start the arc too long to avoid burning through the outer wall of the broken bolt. After surfacing to the upper end face of the broken bolt, a cylinder with a diameter of 14-16mm and a height of 8-10mm shall be surfacing welded.

3. After surfacing welding, hammer the end face with a hand hammer to make the broken head bolt vibrate along its axial direction. Due to the heat generated by the previous arc and the subsequent cooling, coupled with the vibration at this time will cause loosening between the broken bolt and the thread of the machine body.

4. Carefully observe that when a trace of rust is found to leak from the fracture after knocking, the M18 nut can be sleeved on the surfacing column head and the two can be welded together.

5. After welding, it is slightly cool and hot. Use a ring wrench to set it on the nut and twist it back and forth. You can also use a small hand hammer to knock the end face of the nut while twisting it back and forth so that the broken bolt can be taken out.

6. After taking out the broken bolt, use a suitable wire hammer to process the screw thread in the frame again to remove the rust in the hole.