Standard fasteners have their own standards unlike brugerdefinerede fastgørelsesanordninger.
Standardfastgørelseselementer er meget udbredt inden for forskellige områder, såsom maskiner, udstyr, køretøjer, skibe, jernbaner, broer, bygninger, strukturer, værktøjer, instrumenter, kemikalier, instrumenter og slutsystemer, etc.
Det er kendetegnet ved en bred vifte af specifikationer, forskellige ydelsesanvendelser, og en meget høj grad af standardisering, serialisering og generalisering.
If you are the beginner of this field, du bliver ekspert gennem denne guide.
It is mainly manifested in the following 5 aspects.
For non-standard fasteners, which are non-standard parts, detailed drawings are required for new production.
For eksempel, DIN912, the Chinese name is: hexagon socket head screw, which is the name of this product.
Imidlertid, den mest nøjagtige måde er at kalde standarden, fordi GB70 også er det samme navn; but the two standards are not consistent in size in many fields.
De mest indflydelsesrige standarder i verden er: Tysk standard (FRA), International Standard (ISO), Kinesisk national standard (GB), Amerikansk standard (ANSI), og japansk standard (HAN).
2. Standard Fasteners Specifications
Generelt, the name of the screw is the diameter of the tooth pattern * the length of the screw.
Tooth pattern name diameter, commonly used in metric system: M2, M3, M4, M5, M6, M8, M10, M12, etc.
In American system: 4#-40, 6#-32, 8#-32, 10#- 24, 1/4-20, 5/16-18, 3/8-16, 1/2-13, etc.
The length of the screw refers to the effective length of the embedded object.
For eksempel: countersunk head screws are loaded with the total length, half countersunk head screws add half the length of the head, and cylindrical head screws do not include the head size.
For the specification, the full name is best to add the pitch of thread.
For eksempel, M4-0.7×8, the outer diameter of 4 fingers is 4mm, 0.7 means the distance between the two peaks is 0.7mm, and the effective length of 8 fingers embedded in the loaded object is 8mm.
This is only available in the metric system, and American-made products still need to be marked with pitch of thread.
3. Standard Fasteners Raw Materials
Standard fasteners materials are: kulstofstål, rustfrit stål, kobber, aluminium, etc.
Carbon steel is further divided into low carbon steel (such as C1008/C1010/C1015/C1018/C1022), medium carbon steel (such as C1035), high carbon steel (C1045/C1050), and alloy steel (SCM435/10B21/40Cr).
Generelt, C1008 materials are used for ordinary grade products, såsom 4.8 grade screws and ordinary grade nuts; C1015 is generally used for lifting ring screws; C1018 is generally used for machine screws, of course, it is also used for self-tapping screws; C1022 is generally used for self-tapping screws; C1035 hits grade 8.8 skruer; C1045/10B21/40Cr hits grade 10.9 skruer; 40Cr/SCM435 hits grade 12.9 skruer.
Stainless steel material has grade SS302, SS304, SS316, SS904L and SS2205.
Imidlertid, a large number of SS201 fasteners products are also popular now, and even products with lower nickel content, we call them non-authentic stainless steel products;
Although the appearance of SS201 grade looks similar to other stainless steel, the anti-corrosion performance is much different.
4. Standard Fasteners Strength Grade
The strength grade mainly refers to the standard fasteners of carbon steel.
The common strength grades of carbon steel screws are: 4.8, 5.8, 6.8, 8.8, 10.9, 12.9.
The nuts are correspondingly: karakter 4, karakter 6, karakter 8, karakter 10, karakter 12.
Generelt, screws below grade 8.8 are called ordinary screws, while screws above grade 8.8 (including grade 8.8) are high-strength screws.
The difference is that high-strength screws need to be quenched and tempered.
5. Standard Fasteners Surface Treatment
The surface treatment is mainly to increase the anti-corrosion performance of standard fasteners, and some also take into account the color.
Carbon steel fasteners products generally require surface finishing process.
Common surface treatments are: blackening, zinkbelægning, copper plating, fornikling, chrome plating, silver plating, gold plating, Dacromet, varmgalvanisering, etc.
There are many types of galvanized, including blue and white zinc, blue zinc, white zinc, yellow zinc, black zinc, green zinc, etc.
På samme tid, it is also divided into environmental protection and non-environmental protection. Each type of coating has a variety of coating thicknesses to meet different salt spray test results.
Konklusion
Klart, there are other factors to consider when you purchase standard fasteners from China fasteners manufacturers.
The production process, suppliers service, fasteners quality and delivery time will have the huge impact on buyer’s purchasing decisions.
With a proper understanding of every concept in this article, you can easily get a full understanding of standard fasteners selection.
