"From day one, in 1983, we have had our factory here in Portland, Oregon, from which we produced more than 10 million PSTs. From late 1985 until early 1989, in an attempt to fill exponential demand, we also had about 300,000 PSTs produced in Japan. The easiest way to identify the Japan PSTs is that they used rivets, with smooth heads, instead of pins and screws, with knurled heads to connect the blades and jaws to the handles.
The blogger is correct that in the early years we were making changes too numerous to go back and catalog. The slight variations in the PSTs were caused by subtle changes in design, changes in manufacturing methods, and changes in parts due to changes of suppliers.
The approximate date of production for PSTs after November, 1992 is fairly easy to ascertain. Starting in November, 1992, there is a date stamp, month and year, in the bottom of the inside of the handles. The 4 digit date stamp, for example 1192, shows the month and year we blanked the handles in the punch presses in our factory. The blanked handles went into finished tools within a month or so, after completing all the other operations that were done on the handles, and all the other parts that go into a PST, and after assembly of the tool. After that the tools would have been in inventory at our factory, perhaps for only a few days or perhaps longer, depending on demand and season, and then shipped to our customers, and subsequently sold to consumers.
Another complication of identifying the age of tools is that a tool that came back for warranty could have a hodgepodge of parts. For the most part we replaced damaged parts with new parts, but on the other hand we sometimes replaced damaged parts with older parts, still good, cannibalized from older tools."
rg managed to find out an interesting tidbit about the riveted PSTs. I know you're not active over there anymore but it's something I figured you'd like to know.
