| 摘要 |
The invention relates to a preheater plug comprising a body (1) with a heating cartridge (2) and an open-ended steel primary connector (5) of tubular shape (51) with open ends. The central electrode has a smooth end which is accommodated in the through-bore (51) of the connector (3). A laser weld integrally connects the end of the electrode (3) to the interior of the connector (5) through the opening (55) therein. |
