What is the machining accuracy of graphite electrodes?

In order to ensure that the graphite electrode is connected reliably, not loosened, not tripped, and not easily broken during use, the machining of the graphite electrode must achieve high precision. The machining accuracy of the electrode and the joint directly affects the connection quality of the electrode and the joint, and the quality of the connection between the two has a greater impact on the normal operation of the electric furnace and the consumption of the electrode. The processing accuracy of graphite electrodes is greatly affected by the accuracy of the processing equipment itself, and is also related to the tools used, the cutting parameters and the operating level of the operator.

In China's graphite electrode quality standards, for the graphite electrode size deviation and the processing accuracy of the thread shape, only the maximum value of the positive deviation of the electrode joint hole diameter and the maximum value of the negative deviation of the joint diameter are specified, and the end face gap between the two electrodes is not more than 0.4mm , The deviation between the electrode body and the center line of the joint hole is not more than 0.3mm, but there are no clear regulations on other aspects (such as pitch deviation, thread taper deviation, etc.). Therefore, graphite electrode manufacturers should formulate internal control standards for processing accuracy in accordance with user requirements and the actual situation of the factory.

????Using a specially designed combined machine tool for processing, the processing accuracy of graphite electrodes can generally reach the following levels:

(1) Machining the electrode body (conical joint connection). Outer diameter taper: less than 0.15/2500mm, thread effective diameter deviation: 0~+0.1mm, thread taper deviation:

+ 1'~-2', thread pitch deviation: less than 0.02/50mm, thread depth deviation: ±0. 01mm, end surface unevenness: less than 0.05mm.

(2) Machining joints (taper joints). Joint effective diameter deviation: ±0.03mm, taper deviation: less than +2', pitch deviation: ±0.03/300mm, length deviation: 0~-2mm, parallelism deviation of both ends: less than 0.1mm.