Nut protective cap

A nut protective cap relates to the technical field of nut protective devices and comprises a threaded connection portion, a nut containing portion and a bolt tail containing portion, and the surface of an inner cavity of the threaded connection portion is provided with internal threads. A nut accommodating space is formed in the nut accommodating part; the upper side of the nut containing space communicates with an inner cavity of the threaded connecting part, and the nut containing space is provided with a downward opening. The bolt tail containing part is arranged on the upper side of the threaded connecting part, and a bolt end containing space is formed in the bolt tail containing part. A communication channel for communicating the nut containing space with the bolt end containing space is arranged in the nut protection cap, and the communication channel provides a passage for grease to flow between the nut containing space and the bolt end containing space. 一种螺母防护帽，涉及螺母防护装置技术领域，该螺母防护帽包括螺纹连接部、螺母容纳部和栓尾容纳部