Specification for stainless steel tubes suitable for screwing in accordance with bs 21 ' pipe threads for tubes and fittings where pressure - tight joints are made on the threads ' 按bs21 "带压密接合螺纹接头的管及配件管螺纹"攻丝的不锈钢管规范
2.
The advantage is that we work without any risk of breaking taps on particularly expensive work pieces and it saves also a lot of time by simplifying tapping operations 这种夹头的优势：在钻孔和攻丝的转换的时候，只要更换转换接头就可以了，不需要再做其他的调整，带有扭力保护的转换接头可以避免丝锥的断裂，同时还可以节省很多的时间。
