Posted By Bob Baynes I'm running out of time and need to solve this one. I know this is a solveable problem, just short of time to do so. Can't lay my hands on a copy of EN 166 which would probably sort it. Looking at other unanswered threads they were largely, though not entirely, the more obscure questions. Perhaps I have not given sufficient detail to enable a reply to be made. Accordingly, I will try to amplify my problem. This used to be covered by BS 2092 which offered two levels of impact protection, we opted for the higher level. I know that the EN lays down four levels of impact protection which is where the problem is. It appears the medium impact protection equates approximately to the higher level we used under BS 2092. The complicating factor is that not only is this a training situation, but that we are largely training 16 -18 year olds to whom we owe a higher duty of care than to trained, or even untrained adults. If the high impact grade offers more protection, then we should supply it but if the medium grade is adequate then we cannot afford to waste money, our budget is tight. What I need to know is, is the medium impact grade of EN166 adequate for the machining operations I outlined in my original query?

Posted By Bob Baynes Jane, thanks for the info. Though I knew the figures, I had no information on the projectile used. I have talked to one supplier who was very non-commital and unwilling to recommend a particular grade. Guess who won't be getting the order? I know what you mean about chuck keys but have managed to largely eliminate that risk by using keyless chucks in the drilling machines and interlocked guards on the lathes which cannot shut with the key in. The milling machines have table edge, interlocked guards. Now, if I can just manage to persuade them to fasten the work down securely every time...