How To Correctly Describe A Fastener Product Through Its Specification?

It was learned from the survey that many people could not correctly describe a fastener. For example, someone may want to purchase some fasteners, but when communicating the details of what to buy, they are not sure how to describe the fasteners they want to purchase. As a one-stop fastener service company, Xinchi Fastener Company tells you that when describing fasteners, you can say by indicating parameters, which is clear and simple.

The parameters to be specified when describing fasteners are product name (standard), specification, material, strength grade, and surface treatment. Such as DIN912, M4-0.7×8, SCM435, grade 12.9, and blackening treatment.

Product name (standard) : Note: Drawings are required for non-standard screws without standard.

For example, DIN912, its Chinese name is: hex cylindrical head screw, this is the name of the product.

But the most accurate way to do that is to call the standard. GB70 is the same name, but there are many parts of the two standards that are different in size.

The most influential standards in the world are the German standard (DIN), the International standard (ISO), the Chinese National standard (GB), the American standard (ANSI), and the Japanese standard (JIS).

Specification: General screws are called the nominal diameter of thread and screw length.

The nominal diameter of the thread, metric systems commonly used are M2, M3, M4, M5, M6, M8, M10, M12, etc. The US system is commonly used: 4#-40, 6#-32, 8#-32, 10#-24, 1/4-20, 5/16-18, 3/8-16, 1/2-13, and so on.

Screw length refers to the effective length of the screw buried into the object to be loaded. For example, countersunk screws are loaded to the total length, The length of the half-countersunk head screw should be added to the length of the half-head, and the length of cylindrical head screws does not include the size of the head.

For specifications, the full name of the fastener should preferably include the pitch of the thread. For example, M4-0.7×8, 4 refers to the outer diameter of the tooth being 4mm, 0.7 refers to the distance between two tooth peaks being 0.7mm, and 8 refers to the effective length of the buried object being 8mm.

In order to simplify and not write the thread spacing, we will default the coarse teeth to the standard teeth, because it is the most common, so that we do not have to mark. That’s in the metric system. American products still have to mark the tooth spacing.

Here I will focus on the specifications of American screws, such as 6#-32*3/8. 6# refers to the outer diameter of teeth, which is close to 3.5mm; 32 refers to 32 teeth per inch of thread length (equivalent to the tooth spacing of metric screws); 3/8 is the length of the screw (same as the metric screw).

Here are the two formulas to remember: Tooth diameter A#=(Ax0.013+0.06)x25.4(mm), 1 inch =25.4mm.

The following data should be memorized: 2#=2.2mm, 4#=2.9mm, 6#=3.5mm, 8#4.2mm, 10#=4.8mm. The number of teeth corresponding to each specification of screws should also be memorized: 2#-56, 4#-40, 6#-32, 8#-32, 10#-24, 1/4-20, 5/16-18, 3/8-16, 1/2-13(US standard teeth).

Note: American UNC teeth are standard teeth, while UNF teeth are fine teeth. We default coarse teeth to standard teeth.

Material: The most common material of fasteners is carbon steel, stainless steel, stainless iron, copper, aluminum, etc.

Carbon steel is 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 (SCM435/10 b21/40 cr).

C1008 material is generally used to make ordinary-grade products, such as 4.8-grade screws, and ordinary-grade nuts; C1015 is generally used to make ring screws; C1018 is generally used to manufacture machine screws, of course, also used to manufacture self-tapping nails; C1022 is generally used for self-tapping nails; C1035 is used to make class 8.8 screws; C1045/10B21/40Cr is used to make 10.9-grade screws; 40Cr/SCM435 is used to make 12.9-grade screws.

Among stainless steel materials, SS302, SS304, and SS316 are the most common materials. Of course, now a large number of SS201 products, even with lower nickel content, are also popular, we call them non-authentic stainless steel products. Their appearance looks similar to stainless steel, but the corrosion resistance is much different.

Strength grades: Strength grades are mainly used to describe carbon steel fasteners.

Common strength grades of carbon steel screws are 4.8, 5.8, 6.8, 8.8, 10.9, and 12.9. The corresponding strength levels of nuts are Grades 4, 6, 8, 10, and 12.

Generally, 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 between the two is that high-strength screws need to undergo tempering heat treatment.

Surface treatment: Surface treatment is mainly to increase the anti-corrosion performance, but also some consideration of color. So carbon steel products generally need to go through surface treatment.

Common surface treatment methods include blackening, zinc plating, copper plating, nickel plating, chromium plating, silver plating, gold plating, Dacro, hot dip zinc and so on.

There are many kinds of galvanizing, such as blue and white zinc, blue zinc, white zinc, yellow zinc, black zinc, green zinc, and so on. At the same time, it is also divided into environmental protection and non-environmental protection. Each type of plating has a variety of coating thicknesses to meet different salt spray test effects.

Warm tip: This is the general specification of the fastener parameters, but there are a lot of details. For example, the nominal diameter of the thread inside the fastener specification is divided into many kinds, such as ordinary thread (M), pipe thread (C, Rc, Rp, R), trapezoidal thread (Tr) and sawtooth thread (B).

Xinchi Fastener Company is a trustworthy fastener company, especially in furniture nuts. And we are the designated fastener supplier to“STAPLE”. As a trusted fastener supplier,  Xinchi Fastener Company can offer a wide range of high-quality fasteners, including tee nuts, screws, bolts, rivets, washers, etc. If you want to know more about fasteners or want to wholesale fasteners, please feel free to contact us. And then our experienced and expert service team will reply to you as soon as possible.