伟大领袖毛主席教导我们:“古人、外国人的东西也要研究,拒绝研究是错误的,但一定要用批判的眼光去研究,做到古为今用,外为中用。”本文所用资料是经有关生产单位推荐的,主要介绍西德和瑞典加工深孔的实际经验。时间虽然早了一点,但同六十年代末的指标比较(如进给率)并不算低,故仍摘译于此,供有关人员参考。下文凡提到“当时”、“现有”等词实际上均指五十年代初,为免繁琐重复,仍按原文时间译出。——编者注 Great leader Chairman Mao taught us: “The ancients and foreigners should study things as well. It is wrong to refuse the study, but we must study it critically to ensure that the ancient is the present and the outer is the intermediate.” Recommended by the production unit, mainly introduces the practical experience of processing deep holes in West Germany and Sweden. Although the time was a bit earlier, the comparison with the indicators at the end of the sixties (such as the feed rate) was not too low. Therefore, it is still translated here for the reference of relevant personnel. The references to “then” and “existing” in the text below actually refer to the early fifties. For the sake of avoiding repetition, they are still to be translated according to the original time. - Editor’s Note