I hit the pinky side of my hand really hard, on a metal platen, and now it hurts really bad to move it. ?

Sounds: Like you need an xray to make sure you didn't fracture you hand or finger

xray if stil hurts: Is your finger swollen and is there any drainage coming out form it. If you still have trouble moving this finger or still hurting and/or swollen, I will advise you to go to near by emergency room or to see a doctor in his office for further evaluation to make sure that there is no fracture and/or infection. On the other hand, if your symptoms and mobility improving then you might observe