Shaft

Unfortunately with the information provided there is no possible way this could be identified to any particular make or model. For an accurate identification the information needed would be diameter and length of screw section, diameter and length of both machined ends. TPI or pitch of threads, how many thread starts. Whether it is left or right hand thread. From what I can gather from the photos you have a single start right hand Amce thread screw. I could not say this for certain without physical inspection of the item. Any machinist would be able to quickly identify all pertinent information. On the other hand most Acme screws are made in a generic platform and the buyer, usually a machinist machines them to fit his needs. By the length and diameter of this screw it could easily be adapted to many heavy duty small machine applications. My suggestion if you desire to sell this item is get the necessary info from a local machinist, conduct a search of similar screws and price accordingly. There is really no correct answer to this question. It may have all ready been machined for a particular application or that could be factory made to those Specs. My best guess would be a very short toolroom lathe. This is only because of the hole in the shaft is likely for a shear pin. However, we are talking about thousands of machines that could easily use a screw like that. The link provided will help explain my point. Good luck.

References:

http://www.ebay.com/sch/i.html?_sacat=0&_nkw=acme+leadscrew&_frs=1

Reason:
I'll add the dimensions to the listing shortly.