Actally about those lightbulbs they are used if you are a machienist because most led lights tends to flicker which could cause stroboscope effect on fast moving parts and sometimes could present effect that something looks like is moving slower or in different direction that is really moving which could be dangerous. But there are also special machienist led bulbs but are more expensive than normal led bulbs. I am not a profesional machienist so sorry if i didnt describe it correctly but my point is that leds (if are not designed for machienist) are not safe in that particular usecase