Electro Boracic Steel

[Branson]

What the heck is  Electro Boracic Steel?  Dates?  Found the mark on a couple of cooper's tools.

[Papaw]

Wiktor Kruc says-

Beware of the use of scientific sounding trade names. Electro-boracic steel appears on various tools, I have seen it on plane blades, adzes and chisels.

It is a totally meaningless phrase, just a Victorian advertising gimmick.

Source- http://www.wkfinetools.com/hUK/z-UKReading/ironSteelAlloys/ironSteelAlloys2.asp

[Branson]

"... just a Victorian advertising gimmick."  tells me what I want to know.  Now I have some kind of handle on the date of the tools.  One, maybe both were made by Greaves.