Supply welding magnetic ring Filter (aquarium)#Materials suitable for aquarium filtration stud stud welding retainer M10 M12

"There are many names for bolts, and each person's name may be different. Some people call them screws, some call them bolts and nails, and some call them fasteners. Although there are so many names, the meaning is the same, they are all bolts. Bolt is a common term for fasteners. A bolt is a tool that utilizes the physical and mathematical principles of the oblique circular rotation and friction of an object to gradually tighten the mechanical components of the object. [1]
Bolts are indispensable in daily life and industrial production manufacturing, and bolts are also known as the rice of industry. It can be seen that bolts are widely used. The application scope of bolts includes: electronic products, mechanical products, digital products, power equipment, and electromechanical mechanical products. Bolts are also useful in ships, vehicles, hydraulic engineering, and even chemical experiments. Anyway, bolts are used in many places. Precise bolts used in digital products. Micro bolts used for DVDs, cameras, glasses, clocks, electronics, etc; General bolts for television, electrical products, musical instruments, furniture, etc; As for engineering, construction, and bridges, large bolts and nuts are used; Transportation equipment, airplanes, trams, cars, etc. are used with both large and small bolts. Bolts bear important tasks in industry, and as long as there is industry on Earth, the function of bolts will always be important"

"Cross recessed pan head screws refer to cross recessed machine screws, denoted by the letter PM. The national regulations specify that the thread specification is M1.6-M10, the performance grade is 4.8, A-50, A2-70, CU2, CU3 and AL4, H and Z cross recessed pan head screws, and the product grade is A.
If other technical requirements are required, they should be selected from the current standards (such as GB/T196, GB/T3106, GB/T3098.1, GB/T3098.6, and GB/T3098.10)"

"The common types of wooden screws are made of iron and copper, and they can be divided into round head types depending on the nail head
Other samples of wooden screws
Other samples of wooden screws (12 pieces)
Flat head type and oval head type, with two types of screw heads: slotted screws and cross recessed screws. Generally, round head screws are made of mild steel and are blue in color. Flat head screws are polished, and oval head screws are usually cadmium chromium plated. They are commonly used for installing hinges, hooks, and other hardware accessories. The specifications are determined by the diameter, length, and nail head type of the rod. [1]"

As a standard component, it should have its own universal specifications for hexagonal nuts. Commonly used standards include GB52, GB6170, GB6172, and DIN934. The main difference between them is that the thickness of GB6170 is thicker than that of GB52, GB6172, and DIN934, commonly known as thick nuts. In addition, there is a difference in the opposite side. In the M8 nut series, the opposite sides of DIN934, GB6170, and GB6172 are all 13MM smaller than the 14MM opposite side of GB52. The M10 nut series has a 17MM opposite side of DIN934 and GB52, which is 1MM larger than the GB6170 and GB6172. The M12 nut series has a 19MM opposite side of DIN934 and GB52, which is 1MM larger than the 18MM opposite side of GB6170 and GB6172. For M14 nuts, the opposite side of DIN934 and GB52 is 22MM larger than that of GB6170 and GB6172, which is 21MM larger. In addition, the M22 nut has a 32mm across edge for DIN934 and GB52, which is 2MM smaller than the 34mm across edge for GB6170 and GB6172. (GB6170 and GB6172 have the same width across the edges except for their different thicknesses) Other specifications can be universal without considering thickness.