Rodney is right. The plastic pins tend to be smoother. I always use plastic clevises or a screw on ball link on any type of metal arm to avoid metal to metal contact.

FYI - I've been flying R/C since the 70's, have used a lot of plastic clevises and have NEVER had one fail for any reason. However, I do inspect them periodically and replace worn clevises as needed. A lot of guys build the plane and never look at any of the connections again ever. That's just bad news.

One last tip. The night before you go flying, pre-pre-flight your plane at home and look it over good. What I do is give them a good cleaning so they gleam real nice and make me proud. While I'm cleaning I look at everything and then I'm not distracted by others like I am when I do a pre-flight at the field.

I can honestly say I've found a lot of things that needed to be fixed or adjusted that I may have over-looked at the field in the rush to get into the air. For me it's standard operating procedure now. I can't remember the last time I lost a plane due to equipment failure. I wish I could say the same thing about my piloting skills.