Service HotlineHeat treatment broadcast quenching and tempering HB220-270, nitriding HRC>65 foreign use titanium carbide coating method to improve the corrosion resistance of the screw surface, but according to reports, its wear resistance is not good enough. A series of measures have been taken abroad to improve the wear resistance and corrosion resistance of the screw. One way is to use highly wear-resistant and corrosion-resistant alloy steel. Such as 34CrAlNi, 31CrMo12 and so on. There is also a method of spraying Xaloy alloy on the surface of the screw. This Xaloy alloy has high wear and corrosion resistance.
Stainless steel screws do not necessarily corrode and rust, but that stainless steel screws have a stronger ability to withstand corrosion and rust than iron screws. But stainless steel screws can still rust under certain circumstances. So under what conditions are stainless steel screws prone to rust! What is the cause of rust? Stainless steel screws have better characteristics, strong corrosion resistance, high temperature resistance, and strong rust resistance. But it will rust in harsh environments. For example, stainless steel screws are exposed to the sun and the wind every day under very humid conditions. Over time, it will definitely rust a little. For example, in contact with some acid-base chemicals to cause chemical reactions. cause corrosion and rust. There are also bad stainless steel screws, such as stainless steel SUS201 screws used in seawater. Due to long-term immersion, SUS201 stainless steel screws themselves are not suitable for use in salty seawater. cause corrosion and rust. For the use of marine products, it is generally recommended to use stainless steel SUS316 screws, because 316 stainless steel screws have better performance such as corrosion resistance. From the above, it can be concluded that stainless steel screws will still corrode and rust under certain circumstances. Therefore, this requires the rational use of stainless steel screws. Use stainless steel screws of different materials in different situations. And in different occasions, when using stainless steel screws, special attention is also required, and some details need to be considered more. Try to control the corrosion and rust of stainless steel screws as much as possible.
flat washer is also called a flat washer. It is mainly stamped out of an iron plate. The shape is generally a flat washer with a hole in the middle. The size of this hole is generally determined according to customer requirements. There are 9 standards for flat washers in my country. From 2000 to 2002, GB/T97.3-2000, GB/T5286-2001, GB/T95-2002, GB/T96.1-2002, GB/T96.2 were approved and released respectively. -2002, GB/T97.1-2002, GB/T97.2-2002, GB/T97.4-2002 and GB/T5287-2002 Standard for flat washers. According to the performance grade of the flat washer, the author recommends the use of materials: ST12, ST13, Q235, Q215, Q195, etc. can be selected for the 100HV grade, and the surface hardness can reach about 110HV; 08F, 08Al, 10, 10F, etc. can be selected for the 140HV grade etc., the surface hardness can reach about 140HV; for 200HV and 300HV grades, 45, 50, 60, 70 or 65Mn steel should be selected, which can be quenched and tempered by heat treatment to meet the technical requirements of 200~300HV and 300~400HV. Because according to the standard, flat washers of 100HV and 140HV grades can be manufactured from mild steel. Most enterprises use Baosteel materials when selecting materials, which is convenient for cold stamping. The following is a brief description of Baosteel's standards. Compared with the BZJ407-1999 standard, there are major changes in Continuous Cold Rolled Low-Carbon Steel Plates and Strips and the enterprise standard: (1) The grades have been revised and integrated, and the grades have been changed from 8 commonly used to 5. St12 is changed to DC01; ST13 is changed to DC03; St14, St15 is changed to DC04; BSC2 is changed to DC05; St16, St14-T, BSC3 is changed to DC06. (2) The surface quality level is changed from two to three: the higher-level finishing surface (FB), the surface is allowed to have a small amount of defects that do not affect the formability and coating and plating adhesion, such as slight scratches, indentations, Pock, roll printing and oxidation color, etc. Premium Finished Surface (FC) products have no visible defects on the better of the two sides and must meet at least FB requirements on the other side. The super-advanced finishing (FD) product must not have any defects on the better side of the two sides, that is, it cannot affect the appearance quality after painting or the appearance quality after electroplating, and the other side must at least meet the requirements of FB. (3) The surface structure is modified from four to two, and the control value of surface roughness is increased. The average roughness Ra when the surface structure is pitted (D) is 0.6 μm. (4) The provisions on Si and residual elements in the chemical composition of the five grades have been cancelled, and the contents of elements such as C, S, and Alt have been revised.
When the rivet is riveted, it is often necessary to locate and fix the rivet. However, the common rivet positioning mechanism at present often has no way to effectively and quickly remove the restriction on the rivet after the rivet is fixed, which makes it difficult for the nailing mechanism to be inserted. Quickly drive the positioned rivets.
Wood screws, one of which is a polished rod, the angle and pitch of the teeth of the wood screws and self-tapping are different. Self-tapping screws have high hardness, wide thread spacing, deep threads, and uneven surface, while wood screws are the opposite. Another difference is more obvious. Wood screws have no threads at the rear. Self-tapping screws are generally subject to heat treatment, and wood screws are not required. The concept of self-tapping screws is actually very general, because there are many kinds of them according to different head types. Use of wood screws: Similar to machine screws, but the thread on the screw is a special rib for wood screws, which can be directly screwed into wooden components (or parts).
We have many years of experience in the production and sales of screws, nuts, flat washers, etc. The main products are: flat head screws, countersunk head socket head cap screws, small countersunk head bolts, aluminum profile nuts and other products, we can provide you with suitable fasteners for you solution.
