Nope. I think you would come seriously unstuck, in the event of an accident. Follow Reg 11 of PUWER. You can see the newspaper headline now....

Put the 'manager' through some H&S training so they don't bring any other unsafe practices into the workplace! Let's also hope someone makes the correction at the other place before some decent employee has a serious accident. Regards

I'm not so sure stillp. I understand the low speed/power modes, but, to be actually threading by hand, suggests use of a tap or die, "really" this was never even acceptable in a manual lathe, even though we did it. In a CNC, I'm not convinced that a low power mode would make it safe to have your hands and arms in the work area when the machine was operating. Acquiring finishes, sounds like using emery cloth on a lathe, again dubious, and hard to do safely, not impossible, but hard, and hazardous. Moving machines around with guards open, in low speed/power to check out programmes, like you would do to ensure you avoid clash points and like using a robot teach pendant, yes, but I'm not sure about operators leaning into the machine operating area. You would need some pretty robust procedures and practices to prevent things going wrong. Take a CNC turret lathe. You'd probably be in MDI mode, to get the spindle running, now to start, stop and reverse the spindle to use a manual threading tool takes some doing in MDI, the M codes are 3 characters to type, yes you can issue a spindle stop (M05) command more quickly probably via a spindle stop button. The thing is you would have to be in the operating zone with one hand holding the threading tool, and looking out at the control panel to enter the start command etc. It’s physically awkward, and easy to get wrong, please, don’t ask why I know!!! I do still have all my digits and no I’ve not been tangled in one. IMHO it’s fraught with the opportunity for things to go wrong, and if you type M06 rather than M03 then you could instigate a tool change by mistake, with your hand and arm in the operating zone. Look at the 3 & 6 on a numeric keypad. One of the reasons I’m a bit sensitive to this is I know a guy that got caught up in one a lapse in concentration and he nearly lost his hand 6m off work and several surgeries. To cap it off, he was a service engineer for the machine tool manufacturer, the reason it happened is he was so experienced, he knew what the fault was as soon as he looked at the machine, the guards were open, so he stuck his hand in and moved a part, the machine was so fast, it did a tool change and came in and smashed his hand up before he could remove it.

Yes, I meant 'specifically designed' by the machine manufacturer, in accordance with all the relevant ENs. Certainly no bypassing interlocks by the user. Having said that, where I've seen machines with such modes, they are for setting-up rather than for operations like threading or polishing. I posted because some harmonised standards specifically mention reduced speed/power modes that allow the temporary suspension of some safeguards.