Most likely this is a hydraulic cylinder made by "Southern Hydraulic Cylinder Inc." Athens, TN. "Southern Hydraulic Cylinder, Inc. specializes in custom-built, welded, hydraulic cylinders....". There is at least one other cyl. on ebay, no reference to what it's for. The Mfg. date there is "6-25-13" indicating US date format. (Europe would use 25-06-13" The cylinders are custom-built and possibly not in large numbers, so it might be near impossible to find the machine it once belonged to. You *might* get some more info at Southern. (BTW: AHCI Hydraulics B.B. -Netherlands- is for sure NOT the source; this is only a very small trading company not producing anything.). Greetz from HP from the Netherlands ;-)

More information is needed to make an educated guess. Does the ram extend? Provide photos of the actual ends, are they threaded? From the photos, it does not appear there is a ram which extends, OR is there a ram and will the ram extend? If pressure entering one port extends the ram, then the other port has equal pressure flowing out. This is not uncommon. Perhaps in installation only one end of the cylinder is accessable to connect the other hydraulic line? The addition of an extension tube going to the one port would not be difficult. If the ram does not extend, then I believe this is a hydraulic control cylinder. As fluid enters either port, an equal amount gets pushed out of the other port. Fluid extending one cylinder would be equally retracting an opposite cylinder, all cylinders would need to be the same inside diameter It could be used for steering. It could be used for load control or tilting like on a teetter-totter For the moment, without more information, my guess it is a custom cylinder for a limited specific installation.

References:

Only picturing in my feeble brain...

Reason:
The ends are threaded, and I'm unsure if the ram extends, as I'm unable to get it to extend myself. Does this information help at all?

Most likely this is a hydraulic cylinder made by "Southern Hydraulic Cylinder Inc." Athens, TN. "Southern Hydraulic Cylinder, Inc. specializes in custom-built, welded, hydraulic cylinders....". There is at least one other cyl. on ebay, no reference to what it's for. The Mfg. date there is "6-25-13" indicating US date format. (Europe would use 25-06-13" The cylinders are custom-built and possibly not in large numbers, so it might be near impossible to find the machine it once belonged to. You *might* get some more info at Southern. (BTW: AHCI Hydraulics B.B. -Netherlands- is for sure NOT the source; this is only a very small trading company not producing anything.). Greetz from HP from the Netherlands ;-)

References:

http://www.southhydcyl.com (SHC Inc)

http://www.ebay.ca/itm/SHCI-HYDDRAULIC-CYLINDER-1001234-/181821759501?hash=it...