Hello, I have been moving this around for a while, and I have been trying to find out what it is, or used for. The raised letters spell SPEEDMATIC, I am guessing maybe a counterweight for an older machine? I live in Syracuse, NY, not far from the original Porter Cable Plant, and every once in a while, some of their stuff that wasn't sold to the public turns up.This piece measures 12" long, 4" high, and 3" deep., looks like a railroad rail.It weighs 33-1/2 pounds. I have asked some of the locals about this piece, with no luck. Thanks, Lou

I think Porter Cable made a line of Speedmatic tools in the 40's or 50's. Maybe a counter weight for a floor sander or something along that line.

Speedmatic was a trademark of Swingline Inc, the stapler manufacturer. 

Lewill2 is correct.

Before moving I had several tools marked speedmatic an Porter cable.

Hello, I have quite a few Porter Cable Tools here, and a few with the Speedmatic label, routers, planer,  & circular saws. This piece has been a mystery , even to our local Porter Cable Rep. We tried to find someone from the area who may have worked at the old plant, most have either moved, or moved on. Thanks, Lou .  I do do like the idea of it being a weight for a floor sander, time to check the old catalogs.

I hang out over on Old Woodworking Machines as well as here, and got in touch with a few of the Porter-Cable specialists, one of whom is pretty confident that it is, indeed, part of their floor sander.

If you decide you don't need it, he might be interested; but it's not high on his need list either.

I heard from t'other P-C specialist, and he is pretty sure it's from one of the Speedliner floor sanders.  If you can measure it, he offers to tell you which model it would fit, if he can.

I've sent you a private message related to this part.