There are versions of this tube with extended ratings for industrial application which are designated as 6AQ5A (with controlled heater warm-up characteristic), and 6AQ5W/6005 or 6005W (shock and vibration resistant).
There are different versions of this tube designed for industrial applications. Some have extended ratings, labeled as 6AQ5A (with a controlled heater warm-up characteristic), while others are shock and vibration resistant, identified as 6005 or 6005W.