What Are The Applications Of Yellow Zinc Hexagonal Drill Screws?

1. Home improvement

Yellow Zinc Hex Drill Screws can be used for fixing the wooden structure of the family and other building materials. For example, this type of nail can join two panels together more quickly than screws and other nails. It can also be used for home roof and wall installation to ensure the firmness and stability of the home structure.

2. Industrial buildings

In industrial construction, yellow zinc hexagonal drill screws are usually used to fix large pipes, building steel and bridge structures, etc. This type of connector can also be used to attach clapboards, rafters and beams to building skeletons.

3. Transportation

In the transportation industry, yellow zinc hexagonal drill screws are often used to fix ships and marine equipment. It can also be used to build and reinforce road tunnels, bridges and other transportation infrastructure.

4. Furniture manufacturing

Another field of application for yellow zinc hexagonal drill screws is furniture manufacturing. Many pieces of furniture (such as sofas, chairs, beds, etc.) require the use of such connectors to fix the structure between the various components. This kind of nail can guarantee the strength and stability of the furniture.

5. Electronic industry

In the electronics industry, yellow zinc hex drill screws are used to manufacture frames and structures required for electronic equipment. They are widely used in the manufacture of smartphones, laptops and other electronic devices.

In a word, the yellow zinc hexagon drill end screw is a kind of all-round application of building connectors. Its superior performance and economical practicability make it widely used in many application fields such as construction, furniture manufacturing, transportation, and electronics industry.Yellow Zinc Hexagonal Drill Screw is one of the main products of MYWAY Metal, the product is recognized by many enterprises and has a high reorder rate, if you are interested, welcome to contact us at ashley@myway-metal.com, we will send you a complete bolt catalogue and a free discount quotation.

Decarburization and carburization

2. Hardness and Strength

In the inspection of threaded fasteners, we cannot simply look up the hardness value in the relevant manual and convert it into a strength value. There is an influence of hardenability factor. Because GB3098.1 and GB3098.3 stipulate that the arbitration hardness is measured at the 1/2 radius of the cross section of the part. The tensile test specimen is also cut from the 1/2 radius. Because it is not ruled out that the center part of the part has a low hardness and low strength part.

Generally speaking, the material has good hardenability and the hardness can be evenly distributed on the cross section of the screw. As long as the hardness is qualified, the strength and guaranteed stress can also meet the requirements. However, when the hardenability of the material is poor, although the hardness is qualified according to the specified parts inspection, the strength and guaranteed stress often do not meet the requirements. Especially when the surface hardness tends to the lower limit.

In order to control the strength and guaranteed stress within the qualified range, the lower limit of hardness is often increased. For example, the hardness control range of grade 8.8: for specifications below M16, it is 26~31HRC, and for specifications above M16, it is appropriate to be 28~34HRC; for grade 10.9, it is appropriate to control it at 36~39HRC. Grades above 10.9 are another matter.

Hardness and Strength

3. Re-Tempering Test

Bolts, screws and studs of grades 8.8 to 12.9 should be re-tempered for 30 minutes at a temperature 10°C lower than the lowest tempering temperature in actual production. On the same specimen, the difference in the average hardness of three points before and after the test shall not exceed 20HV.

The re-tempering test can check the incorrect operation of using too low a temperature to barely reach the specified hardness range due to insufficient quenching hardness, and ensure the comprehensive mechanical properties of the parts. In particular, threaded fasteners made of low-carbon martensitic steel use low-temperature tempering. Although other mechanical properties can meet the requirements, the residual elongation fluctuates greatly when measuring the guaranteed stress, which is much greater than 12.5um. Moreover, sudden fractures may occur under certain conditions of use. Sudden fractures have occurred in some automotive and construction bolts. The above phenomenon can be reduced when tempering at the lowest tempering temperature. However, special caution should be exercised when making 10.9 grade bolts with low-carbon martensitic steel.

Re-tempering test

4. Hydrogen Embrittlement Inspection

The sensitivity of hydrogen embrittlement increases with the strength of the fastener. For external threaded fasteners of grade 10.9 and above, surface hardened self-tapping screws, and combination screws with hardened steel washers, etc., dehydrogenation treatment should be carried out after electroplating.

Dehydrogenation treatment is generally carried out in an oven or tempering furnace at 190~230℃ for more than 4 hours to diffuse hydrogen.

Threaded fasteners can be tightened on a special fixture until the screw is subjected to a tensile force that satisfies a certain stress, and then maintained for 48 hours. After loosening, the threaded fasteners do not break. This method is used as a hydrogen embrittlement inspection method.

Hydrogen embrittlement inspection