[Steven Smith]

I'd recommend you post your application and math here. I just went through this last night for a different application, and I don't mind reviewing your numbers.

We're considering using them in part as a pincher closure. I'm going to run 3/8"-8, 2start rod at ~ 3 inch/sec closure speed on each of the two arms for 6 inch/sec closure speed total. It is more than adequate from a loading standpoint. The only reason we would want to consider bumping up to a larger diameter would be to more easily support it from a single end without too much whip in the free end... or I might just support both ends and go with 3/8".

Long story short, double check your numbers. These aren't 100% efficient devices, make sure you will have enough power to drive them in your application.