This is interesting - here we always sing the praises of a nice, beefy,
tapered, forged blade - and here is Woodwork 1930 dissing it in favor of a
drawn (I presume) steel parallel-sided blade.

I dunno that I would characterize such a thing "A much better type of
blade"...  Especially in a woodie.

And the assertion that the reason there was a steel bit forged onto an iron
back was because "it is easier to grind ha1f-and-half steel and iron than to
grind a solid steel blade"?  I have always understood it was because (1)
steel was a more precious commodity back then and (2) the iron absorbed the
shock better, while the steel held an edge better, so the combination of the
two made a better blade.

And as far as the back being "left rough-forged"?  That doesn't always have
to be the case.  I'll have to pull a few irons in some of the wooden planes
I have at home, but as I recall, they're all pretty well smooth and flat.

- Bill T.
- Age-old questions that remain debatable still, I guess...

-----Original Message-----
Another cause of chattering i(s a faulty blade. Most
planes are fitted with a tapered blade, as at Fig 3,
consisting of a small piece of steel which is forged on
to a wrought iron blade, The idea being that it is easier
to grind ha1f-and-half steel and iron than to grind a
solid steel blade. Many of these irons are left rough
forged at the back and consequently they do not bed accu-
rately on to the frog of the plane. Furthermore, as this
type of tapered blade is ground away to, say, the line A
it increases the opening at the mouth of the plane. This,
of course, is obvious owing to its tapered length. A much
better type of blade is the gauged iron depicted at Fig 4.
in this case the iron is parallel in thickness and the
back of the blade is ground and polished perfectly flat
and out of winding. All American pattern iron planes have
this gauged type of iron to ensure that they bed evenly on
the frog and to prevent any increase in the opening of the
mouth as the blade is worn shorter in length. This method
is of course, theoretically correct.

------------------------------------------------------------------------