GG,

This is not a scientific study (low sampling number, etc), but
I was supervised by an engineer and the machine is accurate to
±1 Hardness Rockwell C. Just for the heck of it...
The numbers stated are from the average of 3 readings. If other
Galoots have data for legendary outperforming tools, for other
time periods,  please send them in for comparison.
Or, you could always send me your infill for testing... ;-)

Plane irons                                       HRC
 Record #7 T14 Tungsten steel, laminated          63.2
 Stanley #4 SW laminated                          62.6
 Stanley #5 SW laminated                          62.3
 (Rev. Hock says 62 for his blades)
 (LN states 60-62)

Saws
 No.7 Disston Philada                             48.5
 D8 Disston Philada                               44.0
 No.12 Disston Philada                            48.5
 #4 Backsaw Disston Philada                       48.9
 Bow saw blade, no mark, 24 x 1 in.               52.0
 (3 for $1.50, drive by...)
 (LN Ind. dovetail saw suppose to be 52)

Chisels
 Marple Blue Chip                                 58.8
 TH Witherby Warranted bevel edge                 62.4
 Stanley #720                                     60.8

#66 beader blades
 orig. Stanley reeding                            54.5
 LN router blade                                  62.0

#45 blades                                   62.1-63.2
#46 blades                                   63.5-63.7

EC Atkins No.5 scraper blade                      51.4

When I told him the age of some blades we were testing,
the engineer was impressed at the hardness attained.
He was also surprised that the teeth of the saws could
be bend with out breaking when the metal had a hardness
of 48-52, I didn't know better...

Louis Michaud