跳至主要内容

Common standard knowledge of screws

The dimensions, mechanical properties and functional performance of self-tapping screws have the following standards
　　American National Standards Institute (ANSI)/ASME B18.6.4─Thread forming and thread cutting self-tapping screws and metal drive screws (inch series)
　　SAE J933─Mechanical and quality requirements, self-tapping screws
　　J81 screw thread rolling─SAE
　　SAE J1237─Metric thread rolling screw
　　SAE J78─steel self-tapping screws
　　FIP 1000─self-tapping screw performance specifications
　　DIN 7500─Thread Rolled Screw ISO Metric Screw Line
　　DIN 7504─Self-tapping screw size, requirement and test
　　ISO 2702─Tapp heat-treated steel
 
U.S. regulations

a. Generally marked with a serial number, such as #2-56, #4-40, #6-32, #8-32, #10-24…etc.
b. Or expressed in English outer diameter, such as 0.086-56, 0.112-40, 0.138-32, 0.164-32, 0.190-24...etc.
Ex: 632 – 8 – P P B:
Finish Code: Appearance processing specifications
Head Code: Head shape
Drive Code: head section groove, characteristic model
Length Code: Screw length
Thread Code: Screw model
B-1: Thread Code: Screw model
B-2: Length Code: Screw length (B-3, B-4, B-5: The marking method is the same as the metric system)
The length of US-standard screws must be converted to the metric mm size. Conversion formula: (Length Code / 32) x 25.40 = metric length mm

评论

发表评论

此博客中的热门博文

How to distinguish between high-strength nuts and ordinary nuts?

What is the difference between high-strength nuts and general nuts, in fact, you only need to understand their standards and other characteristics to easily distinguish them. The so-called high-strength nut is a special bolt with high strength and high fatigue resistance used in special equipment or engineering. Of course, generally high-strength nuts are used with high-strength bolts to achieve better application. We generally see that many bolts with M heads in the market are ordinary nuts, not high-strength nuts. The calibration side of the general hexagonal head nut is the following pattern M30, and M30 indicates the thread standard, that is, the inner diameter of the thread is 30mm. Grade 10 indicates the functional grade of the bolt, and tZn is the surface treatment method. Other types of bolts also have their own expressions, but generally threaded bolts have to use the original functional grade of "M": The functional level of the nut is divided into 3, 4, 4, 5, 5.8, 6...
1 条评论
阅读全文

Is the material of stainless steel screws magnetic?

There are many types of materials for making stainless steel screws, and they can be divided into several categories according to the structure at room temperature: austenitic type: such as 304, 321, 316, 310, etc.; martensite or ferrite type: such as 430, 420, 410 Wait;   Austenite is non-magnetic or weakly magnetic, while martensite or ferrite is magnetic. Due to component segregation or improper heat treatment during smelting, a small amount of martensite or ferrite in austenitic 304 stainless steel will result. In this way, 304 stainless steel will have weak magnetic properties.     After 304 stainless steel is cold worked, the structure will also be transformed into martensite. The greater the degree of cold working deformation, the more martensite transformation and the greater the magnetic properties of the steel. Like a batch of steel belts, Φ76 tubes are produced without obvious magnetic induction, and Φ9.5 tubes are produced. Because the bending deformation...
发表评论
阅读全文

How to prevent stainless steel screws from rusting

 Analysis of the causes of rusty hardware screws: 1. When the electroplating factory is electroplating hardware screws, the drying is not done, resulting in residual water vapor. Or, after drying, condensate is formed during packaging. Dongguan Electronic Screw Factory introduces to you, it causes chemical reaction, produces bad occurrence, and causes hardware screw to rust. 2. Stored in a humid place for a long time. Over time, the hardware screws will slowly be corroded and oxidized, causing serious rust. 3. When electroplating hardware screws, the electroplating is poor, and the electroplating layer is too thin. Cause rust. All in all, analyze the reasons from four aspects.   The four directions are: 1. Storage environment 2. Types of electroplating 3. How to save 4. Use environment. Therefore, we must pay attention to the key points in the use of stainless steel screws: 1. The surface of the stainless steel screw adheres to the organic juice (such as melon, vegetable, nood...
发表评论
阅读全文