2014 US uniface cent

Hi came across this cent 2014 shield type,the obverse is as it should be but the reverse is of a different metal (non magnetic).You can see a faint outline of the shield design but no lettering.Does anyone have any ideas about what this is,maybe a mint error?

nice find!
'capped die' error, I believe.

Thanks could you explain a capped error for me please and do you think it has any value?

http://www.lincolncentresource.com/Errors/Capped_Die.html

That doesn't explain the missing copper plate on the reverse. Maybe sanded off? What is the thickness?

Around 2 mm

These coins are zinc with copper cladding I believe.Could this be missing the cladding.At first glance I thought it had been put on after mint but surely you would see other details and there are scratches where someone has tried to see if they could remove it but that thing is solid

It's zinc plated with copper. The copper is very thin, about .02 mm. The zinc is plated with the copper when it is a blank. Normal coin thickness is 1.52 mm. Yours is thicker than a normal coin? Can you take a picture of the edge? Your pictures are very small. Hard to see anything.

Thanks for your interest.I have taken a close up of the reverse,doesn't look sanded to me, and a close image of the edge.You can clearly see the 2 different metals either side so maybe it has been machined

Oh by the way the coin weighs 2.4 g about right for this type

I'm still thinking PMD. Here's one I made yesterday. It also weight 2.4g.

Many thanks I guess we can put this one to bed now