With the current complexity of fastener products, many users are particularly hesitant when choosing some bolt and nut accessories. For example, in the selection of flat gaskets, it will be difficult to choose. Here are 5 selection criteria for gaskets.
(1) When selecting the gasket material, attention should be paid to the problem of electrochemical corrosion when different metals are in contact. The material of the flat washer is generally the same as the material of the connected parts, usually steel, alloy steel, stainless steel, aluminum alloy, etc. When there is a requirement for electrical conductivity, copper and copper alloys can be used.
(2). The inner diameter of the flat washer is selected according to the larger value of the thread or screw diameter. The connected material is softer (such as composite material) or matched with the spring washer. The larger outer diameter should be selected.
(3). When you choose to place the W washer under the bolt or screw head, in order to avoid the interference between the rounded corner under the head and the washer, a flat washer with an inner hole chamfer can be used.
(4) For important bolts with larger diameters or in order to increase the resistance to extrusion, steel washers should be used. Steel washers shall be used for the connection of tension bolts or composite shear bolts.
(5). Special gaskets are used in the parts with special requirements, such as copper gaskets that need to be conductive; sealing gaskets that have air tightness requirements.