Hi,
Measure the angle? Yeah measure the angle.
I used inkscape to measure the angle in the pictures,
its about 22.5 degrees give or take ,
which is common pull through slot gadget / cooking school chef steeling angle
You can also use permanent marker trick to measure edge angle,
thats paint the edge with a marker,
then put abrasive (ex stone) on an angle (ex 15 degree cardboard triangle)
and take a stroke with blade "perfectly" horizontal
and see where the marker is being removed
if its removed on edge shoulder angle is higher than 15
if its removed or edge apex but not on edge angle is lower than 15
if its removed on edge apex and behind apex then angle is 15
How do you make a cardboard triangle?
pencil and protractor
or
PocketProtractor
or pencil and ruler and
1/60 rule or calculator
Side a = 53.58984
Side b = 200
Side c = 207.05524
Angle ∠A = 15° = 0.2618 rad = π/12
Angle ∠B = 75° = 1.309 rad = 5/12π
Angle ∠C = 90° = 1.5708 rad = π/2
Or Get a pencil, millimeter ruler , and paper
-) pencil mark a spot on the blade where you will measure
-) use ruler to measure in mm the width of blade , the run, write it down ex (run 47mm)
then at the same spot of the blade
-) use ruler to measure in mm the spine thickness , write it down, divide by 2, write +result in a circle, ex 4mm / 2 = ( +2mm )
-) put pencil on table, lay blade flat against against pencil, while you slide blade slowly along pencil, raise the spine until the edge bites into the pencil then stop
then at the same spot of the blade
-) use ruler to measure in mm the height from pencil to spine, write down 11mm+spine2mm = rise 13mm
*if your ruler doesnt start counting millimeters from the edge, wrap paper around ruler, mark height, then unwrap paper and measure
then punch in some numbers into
triangle-calculator hit the calculate button and get the actual angle
Side a = 47
Side b = 13
Side c = 48.76474
Angle ∠A = 74.539° = 74°32'20" = 1.30095 rad
Angle ∠B =
15.461° =
15°27'40" = 0.26985 rad
Angle ∠C = 90° = 1.5708 rad = π/2
Yes millimeter ruler works easier with wider blades.
Also its not hard to eyeball a fractions of a millimeter , ~10.5 , more or less, 10.7 , 10.9,
calipers/micrometer work better in that regard
Also a protractor and laserpointer could be used ...