"Michael Terrell" wrote in message
...

On Monday, October 5, 2020 at 7:36:41 AM UTC-4, Jim Wilkins wrote:

The search term is "steel rule".
http://www.wagnerdiesupply.com/Image...Guide-2016.pdf

PT stands for Point, 1/72", the traditional measuring unit of the printing
trade.

The cartons were labeled 'Die Knife' back then. Either the name was
changed, or their suppliers used a trade name for that industry which isn't
unusual. I haven't been in a corrugated box plant in over 30 years. There
were five where I lived, in Ohio, but there are none close to me, here in
Florida. The ones on Ebay were in a carton marked Die Knife. That was the
search term that I used. It was a partial carton, and no telling how old it
was. There is little to no reason to date code the shipping cartons.

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Googling for '"die knife" wasn't very productive.
http://www.joinordieknives.com/

"Steel rule die cutting blades" gets results.
https://www.freemansupply.com/brochures/dieboard.pdf