Fasteners include: bolts, studs, screws, nuts, washers, pins Fasteners are also called standard parts on the market. It is a kind of mechanical parts used for fastening and connection, and it has a wide range of applications. The characteristics of fasteners: There are many varieties and specifications, different performances and uses, and the degree of standardization, serialization and generalization is extremely high. Therefore, some people call a type of fasteners that have national (industry) standards as standard fasteners, or standard parts for short.

Because the specifications, dimensions, tolerances, weight, performance, surface conditions, marking methods of each specific fastener product, as well as the specific requirements for acceptance inspection, marking and packaging, are separately stipulated in several national (industry) standards , Such as the British system, the German system and the American system. Fasteners are the most widely used mechanical basic parts. With my country’s accession to the WTO in 2001, it has entered the ranks of major international trading nations. my country’s fastener products are exported to various countries in the world, and fastener products from all over the world are also pouring into the Chinese market. Fasteners, as one of the products with a large import and export volume in my country, are in line with international standards. It is of great significance to promote Chinese fastener companies to the world and to promote the full participation of fastener companies in international cooperation and competition. Strategic significance.

Fasteners are a general term for a type of mechanical parts used when two or more parts (or components) are fastened and connected into a whole. Also called standard parts on the market.

It usually includes the following 12 types of parts:

1. Bolt: A type of fastener consisting of two parts, a head and a screw (cylinder with external threads), which need to be matched with a nut to fasten and connect two parts with through holes. This type of connection is called bolt connection. If the nut is unscrewed from the bolt, the two parts can be separated, so the bolt connection is a detachable connection.

2. Stud: There is no head, only a type of fastener with threads on both ends. When connecting, one end of it must be screwed into the part with internal threaded hole, the other end must pass through the part with through hole, and then the nut is screwed on, even if the two parts are tightly connected as a whole. This type of connection is called a stud connection, which is also a detachable connection. It is mainly used where one of the connected parts has a large thickness, requires a compact structure, or is not suitable for bolt connection due to frequent disassembly.

3. Screw: It is also a type of fastener composed of two parts: head and screw. According to the purpose, it can be divided into three categories: machine screws, set screws and special purpose screws. Machine screws are mainly used for a tightening connection between a part with a threaded hole and a part with a through hole, without the need for a nut to fit (this type of connection is called a screw connection, which is also a detachable connection; it can also be Cooperate with the nut, used for the fastening connection between two parts with through holes.) The set screw is mainly used to fix the relative position between the two parts. Special purpose screws such as eyebolts are used for lifting parts.

4. Nut: With internal threaded holes, the shape is generally flat hexagonal column, and also flat square column or flat cylinder. It is used with bolts, studs or machine screws to fasten and connect two parts. It becomes a whole.

5. Self-tapping screws: similar to machine screws, but the thread on the screw is a special self-tapping screw thread. It is used to fasten and connect two thin metal components into one piece. Small holes need to be made in the component in advance. Because this kind of screw has high hardness, it can be directly screwed into the hole of the component. Form a responsive internal thread. This type of connection is also a detachable connection.

6. Wood screw: It is also similar to machine screw, but the thread on the screw is a special rib for wood screw, which can be directly screwed into the wooden component (or part) to use a metal (or non-metal) with a through hole. The parts are firmly connected to a wooden component. This connection is also a detachable connection. 7. Washer: A type of fastener with an oblate ring shape. It is placed between the supporting surface of bolts, screws or nuts and the surface of the connected parts, which increases the contact surface area of the connected parts, reduces the pressure per unit area and protects the surface of the connected parts from damage; another type of elastic washer, It can also play a role in preventing the nut from loosening.

8. Retaining ring: It is installed in the shaft groove or hole groove of the machine and equipment, and prevents the parts on the shaft or hole from moving left and right.

9. Pins: Mainly used for positioning parts, and some are also used for connecting parts, fixing parts, transmitting power or locking other fasteners.

10. Rivet: A type of fastener consisting of two parts, a head and a nail shaft, used to fasten and connect two parts (or components) with through holes to make them into a whole. This type of connection is called rivet connection, or riveting for short. Belong to and non-detachable connection. Because to separate the two parts connected together, the rivets on the parts must be broken.

11. Assembled parts and connection pairs: Assembled parts refer to a type of fasteners supplied in combination, such as a combination of machine screws (or bolts, self-supplied screws) and flat washers (or spring washers, lock washers); connection; The secondary refers to a type of fastener supplied by a combination of a certain special bolt, nut and washer, such as a high-strength large hexagonal head bolt connection pair for steel structures.

12. Welding nails: Because of the heterogeneous fasteners composed of light energy and nail heads (or no nail heads), they are fixedly connected to a part (or component) by welding so as to be connected with other parts.

Each fastener product must involve some standards in several aspects: 1) Fastener product size standards: specify the content of the basic size of the product; for threaded products, it also includes the basic size of the thread, thread end, shoulder distance, undercut and chamfer, and the end of external threaded parts Dimensions and other aspects.

2) Standards for the technical conditions of fastener products. Specifically, it includes the following standards:

a) Fastener product tolerance standards: specify product size tolerances and geometric tolerances.

b) Mechanical performance standards of fastener products: specify the marking method of product mechanical performance levels and the content of mechanical performance items and requirements; some fastener products will change this content to product material performance or work performance Aspect content.

c) Standards for surface defects of fastener products: specify the types and specific requirements of product surface defects.

d) Surface treatment standards of fastener products: specify the types of product surface treatments and specific requirements.

e) Fastener product test standards: specify the test contents of the various performance requirements mentioned above.

3) Fastener product acceptance inspection, marking and packaging standards: specify the qualified quality level and sampling plan of the random inspection items during the factory acceptance of the product, as well as the content of the product marking method and packaging requirements.

4) Standards on the marking method of fastener products: specify the complete marking method and simplified marking method of the product.

5) Other standards of fasteners: such as the standard of fastener terminology, the standard of fastener product weight, etc.

Standard (German standard and American standard are commonly used)

GB (National Standard)

ISO (International Standard)

DIN (German system)

JIS (Japanese standard)

ANSI /ASME (American National Standards Institute-ANSI; American Society Of Mechanical Engineers-ASME) (American Standard)

BS (Inch) IFI =Industrial Fastener Institute is the standard of the American Industrial Fastener Association. BA (Inch)

Thread

M. MF (Metric Tooth)

UNC. (American Coarse Tooth)

UNF (American fine teeth)

UNEF (U.S. ultra-fine teeth)

B.S.W. Standard Wyeth Coarse Thread Series, General Purpose Cylindrical Thread (Inch Thread)

B.S.F. standard Wyeth fine pitch series, general purpose

Cylindrical thread (inch thread)

Fine pitch thread full thread

Screw head type

IHH=ind hex head saw hex head

PH=phillips cross groove

Pan round head (pan head)

Oval half countersunk head

H.W.H.. Hexagonal small flange

H.W.F. Hexagon Large Flange

CSK Salad Head (Sink Head)

Large wafer

Bugle horn

Truss pan head with cushion

Pozi metric trough Serra-tion under the cushion with flowers

Flower Head Flower Head

6-bobes recess

Cup head

Common fastener names

split washer spring washer (generally manufacturers will call washer “washer”)

flat washer

Self tapping screw

Self drilling screw

drywall screw drywall screw/drywall screw/wall screw

high low screw

collated screw

Concrete screw

Tri-lobular thread screw

kep nut

acorn nut stainless steel screw wire

wing washer

eye bolt eye bolt (also called eye bolt, in fact, this is called a lot, probably because of different regions)

Piston bolt

Winding bolt

Hexagon head bolts

Hexagon flange bolts

Hexagon flange bolts

Carriage bolt Carriage bolt Square head bolt

Flat countersink square neck bolts

Flat counter sunk nib bolts

Cross recessed pan head tapping screws

(If you see # 2 or # 20, etc. on the drawing, it means that the head of the screw is suitable for a No. 2 or No. 20 screwdriver)

Surface treatment

BO=black oxide oxidation blackening (if only black is marked, it means that it is dyed black)

Zinc plated

cementation

Nylon patch is resistant to falling (when I first saw it, it was a literal translation of “nylon sheet”. When it was shown to the manager, the manager looked at the drawing for a long time and told me that you should check the English of resistant to falling, sure enough— )

Raw material: Raw material

Spheroidizing annealing: Annealing

Cold drawing: Drawing

Cold heading: Forming

Machining: Machining

Thread forming: Roll Threading

Heat treatment: heat-treatment

Surface treatment: finish

ehydrogenation: Lustrating hydrogen

Inspection: Inspection

Customs code

73181500 bolt

73181600 nut

73182100 Washer

73181100 square head screw

73182300 Rivet

73181400 Self-tapping screws

73182400 Pin and open tail pin