The origin of the threads of the bimetallic thermometer

Bimetallic thermometer with many different kinds of screw thread, standard is very much also. But the effect is the same, which is used to seal. You know the origin of the threads of the bimetallic thermometer? We said this today. American thread, for example, American general use sealing thread is by Robert. Mr Cloth, proposed in 1840. In 1919, general purpose seal screw ASA B2 is issued to the national standard. 1 - 1919. In 1945, the United States dry sealing thread is put forward. Released in 1960, American dry sealing thread ASA B2 to the national standards. 2 - 1960. American dry sealing thread higher requirements on the sealing performance. Its single thread parameter accuracy ( Tooth high Angle, pitch and tooth side) Is higher than the American general use sealing pipe thread. It at the top of the teeth with tooth ascend to cooperate for surplus; The American general use sealing screw thread at the top of the tooth and tooth to ascend a transition fit. American dry sealing pipe thread is mainly used for special occasions have strict request for sealing, such as gas, automotive, aircraft, spacecraft, etc. American-made ganmere pipe thread does not necessarily opposed to within the thread, deputy add sealing medium, not one-sided understanding & other; Dry seal & throughout; The meaning of. There are two kinds of american-made sealing pipe thread type, & other; Cone/cone & throughout; And & other Column/cone & throughout; 。 Us well dealing with the two kinds of screw thread gauge is compatible with each other, using a gauge can test two sealing pipe thread. The purpose of thread main is sealed. Know the origin of the thread, can help us choose suitable screw