Application error of Dacromet hexagon bolt
1、 Substitute coarse for fine
Some parts are connected with fine thread, but in the process of maintenance, the fine thread Dacromet hexagon bolt is lost or damaged, but there is no original matching, some people use coarse thread bolt instead, which is actually very undesirable. Replacing the fine with the coarse is easy to lead to loosening and falling off.
2、 Void mismatch
Usually those bolts that can bear shear force and transverse load need to be well matched with bolt hole to play its role of fixation. If there is a certain interval between bolt and bolt hole during assembly, it is easy to cause loosening and falling off in the future.
3、 Torque mismatch
We generally think that the tightening of Dacromet hexagon bolt should conform to the principle of “tightening but not loosening”. Therefore, some people unconsciously increase the tightening torque during installation, which will lead to sliding buckle. In addition, some people in the installation due to insufficient torque, resulting in bolt loosening, whether the torque is too large or insufficient should be avoided.
4、 One mother with many pads
During the installation, sometimes it is found that the Dacromet hexagon bolt is too long. In order to avoid the unsightly situation caused by too long, some people will put on a lot of spring washers. In fact, many spring washers are easy to cause uneven stress, which will reduce the bolt preload and reliability.
5、 The washer is too large
In the assembly process, because there is no suitable washer, some people will use the washer with a slightly larger diameter to replace it. In fact, this will lead to the decline of bolt tightness. Too large washer will make the contact area between the bolt head and the washer smaller, thus reducing the support pressure of the washer.
In addition, when installing, it is necessary to avoid false firmness, such as the dust, rust, burr, impurities and other things on the bolt hole and bolt, which will affect the screw in of the bolt.
ASTM A193 B7 Heavy Hex Bolts and Nuts Standard: ASME B 18.2.1, DIN931, Din933, ISO4014, DIN6914,A307, A325,A449, A490,A354 GrBD, A193 B7 Diameter: 3/8”~2” , M12-M50 (3/8”,1/2”,5/8”,3/4”, 1”, 1 1/2”,1 1/4”,13/4”,2”) Length: 5/8”~20”, 16mm-500mm Material: carbon steel 45#, alloy steel, 40CR, 35CRMO, 42CRMO, 4140, BY Grade: Grade 2 / 5/ 8; CL4.8/CL8.8/ CL10.9/CL12.9; Finish: black oxide, […]