General rule: φ3.8 +0.043/+0.027.
Stop gauge: φ 4.2+0.00/-0.0 16 independent principle.
Under MMC condition, the pin size is φ 3.8mmc-φ 0.4 = φ 3.4.
When the benchmark also has MMC, it is necessary to subtract the difference between the benchmark measured value and the benchmark MMC.
For example, if the difference between the reference measured value and the reference MMC is 0. 1, the pin size is φ 3.4-0. 1 = φ 3.3.
Extended data:
The bolt consists of a socket and a plug. Attention should be paid to the following items when using:
(1) The socket should not be installed in a high-temperature and humid place, but in a dry and clean place; The height of surface-mounted sockets from the ground shall not be less than 1.8m, and the height of concealed and industrial sockets from the ground shall not be less than 30cm.
(2) The rated current of the bolt should be greater than the load current; There should be obvious differences between sockets with different voltages, and they should not be mixed.
(3) The sockets of all portable or mobile electrical equipment shall be three hole socket exclusive type, and three four-hole sockets shall be used accordingly, and their grounding holes shall be connected with the grounding wire or zero line.
(4) The sockets in children's activity places should adopt safety sockets; If ordinary sockets are used, the installation height should not be lower than1.8m. ..
(5) Two or more electrical appliances are not allowed to share a plug or two pairs of plugs are inserted in the same socket to prevent short circuit or electrical appliance burning accident.
(6) It is forbidden to directly insert the ends of two power cords of electrical appliances into the jack of the socket to avoid short circuit or electric shock.
(7) After the bolt is damaged, it must be replaced in time and cannot be used.
(8) Always check whether the bolts are in good condition and whether the threads of the plug or socket terminals are loose.
(9) Insert the plug into the socket to the end, and do not expose it (as shown in (c) on the right) to avoid electric shock.
Baidu encyclopedia-bolt