Following hsbcn: You will have to be much more exact.
The three materials will have differencies in different degrees for at least: corrosion resistance, weather (snow, water, sun) resistance, heat leading and shielding factors, construction strength, fabrication and maintenance cost, shock resistance, vibration damping resistance, radiation resistance, fire and explosion resistance, mechanical wear and abrasion resistance, detoriation over time (plastic and UV light?), weight, mounting/demounting and mounting of extra accessories and equipment, etc. etc.
In addition plastic, aluminium and steel are general descriptions which can vary and overlap in qualifications from material to material depending on exact alloy or plastic type and surface treatment/finish. Actuators type, size and applications can vary in a vast number.
In addition to Gerhardl's excellent list, some manufacturer's only produce their actuators with a limited number of casings (e.g., if you like the features and cost of a RoTork actuator you accept a cast steel casing).
"Belief" is the acceptance of an hypotheses in the absence of data.
"Prejudice" is having an opinion not supported by the preponderance of the data.
"Knowledge" is only found through the accumulation and analysis of data.
The plural of anecdote is not "data"
Hey sorry about the quick and general question didn't have a whole lot of time at the moment but wanted to ask it before it left my train of thought which is pretty short these days...
I am working on a a new product design for a small multi-turn electric actuator and before having the mold made I wanted to gather some facts and opinions about the materials. The three I had in mind are-
1.) 300 series stainless steel
2.) 319 aluminum allow with nickle plating
optional (about .0008in)
3.)20fiberglass filled poly carbonate.
This actuator will be subjected to as low as -70f and the harshest environment I can think of is strapped to the side of an off shore oil rig.
This would probably be best handeled as a market/end-user research. As ultimate offshore-products for North-Sea qualifications (or subsea) the al and SS might not qualify, and I do not know about your plastic. This is a limited market. Ask offshore north-sea related companies if this is interesting.
For the naval (merchant and navy) and industrial market you could compare with price, quality, performance and materials from a multitude of competitors.
