Patrick L. wrote,
 
> Jeff Gorman  writes:
 
> >However /when planing/, a reduction of the angle is not necessarily a
> >benefit if tackling gnarly grain, since a higher angle and hence more
> >of a scraping action is often beneficial, hence the greater angle
> >(47.5?) of Norris planes and the "York" pitch of 50 degrees.
 
>   The vast, and I mean VAST, majority of bench planes are pitched at
> 45 degrees. Even the mighty infills are rarely pitched differently.

   We're giving Kingshott such publicity that I'm sure he won't mind
   my quoting him from p.66 of his tome of infamy,

   "Most current mass-produced bench planes have a pitch of 45 degrees,
   which is known as common or standard pitch.  Smoothers made in years
   gone by to plane difficult hardwood had a pitch of 50 degrees, known
   as York pitch.  Thomas Norris compromised by making his bench planes
   with a pitch of 47.5 degrees.

   Cabinetmakers who worked difficult woods with easily torn curly
   grain made their own smoother; this tool would have a pitch as steep
   as 55 degrees, called middle pitch.  Moulding planes, with a single
   iron set with the bevel down, need to have a steep pitch to prevent
   the grain tearing out - some are as steep as 60 degrees."

   Now, I'll say that I don't have the total low-down on what Kingshott's
   qualifications are.  It seems, though, that this would not be his
   original convention.  And he claims to have some direct experience of,
   even owned perhaps, a number of Norris planes.  

   So what is it?  It's 45, or it's 47.5, or what.  Kingshott has torn
   these things apart to measure and blueprint them, etc., allegedly.
   I really don't know what to say here.

> There is no good reason to pitch the iron higher when the plane is
> equipped with a double iron and the plane is made from metal, which
> allows a finer mouth than wood can offer.

   In a related quote, the great woodworking Asimov Sam Allen, on
   p. 49 of his plane opus, writes,

   "Most bench planes have a bedding angle of 45 degrees. [...]
   A higher angle makes the plane harder to push, but leaves a
   smoother cut.  Common [45] pitch is a compromise that gives a
   satisfactory cut with a moderate amount of pressure.

   Hardwoods will be planed smoother if a plane with York pitch
   [50 degrees] is used.  Some wooden planes are available with
   York pitch.  Burl wood and other highly figured wood can be
   planed with less tearout if an even higher bedding angle is
   used."

   Being an Asimov, though, he's obviously picked this up 
   somewhere else.
   
>   Wooden bench planes can be found with various pitches to them, but
> even these are usually pitched at 45 degrees. 

   Dunbar, on pp. 41-42, write,

   "On most bench planes, this [pitch] is 45 degrees, and is known
   as the common pitch.  Such planes were meant for everyday use,
   and they work best on soft woods.

   However, some planes were made specifically for working hard
   woods and have a pitch of 50 degrees, called a York pitch.
   Cabinetmakers who regularly worked heavily figured woods such
   as walnut or mahongany might own a smoothing plane with its
   blade set at an even steeper angle of 55 degrees.  This is
   called the middle pitch.  There is a more extreme set of 60
   degrees known as the half pitch, also intended for heavily
   figured woods such as curly maple.

   Planes with the middle and half pitch work like scrapers and
   are difficult to use on soft wood such as pine."

   This is in the context of bench planes, FWIW.  Again, I don't
   know what Dunbar's qualifications are.  He's obviously getting
   this somewhere.
 
>   One thing has been lost in this 'pitched battle' - as the pitch is
> increased, the escapement for the shaving narrows. This can lead to
> the plane choking unless the escapement is made wider. 

   Agreed.

   You go on to present a case that, in order to accomodate that, the
   form, or shape of the plane, particularly as regards the shape of
   the infill, and various ergonomic issues, must be modified 
   accordingly. 
 
   [ stuff about the moulding planes tamped ]

> --------------------------------------------------------------------------
> Patrick Leach
> Just say A 45 degree pitch was done for good reason.
> etc.
> --------------------------------------------------------------------------

   It was mentioned earlier that even the mighty Japanese, with 
   their reputation for fine smoothers, bedded at 45 or below.
   But if you look thru the catalogues such as Japan Woodworker,
   when such a plane is aimed at the woodworker dealing with
   hardwoods and exotics, a pitch of 47.5 is more common among
   them.

   In FWW #99, p. 70, Starr's article on planes makes an
   interesting reference:

   "The Victorian expert Charles Holtzapffel in v. II of "Turning
   and Mechanical Manipulation" [...] suggests various (iron)
   pitches for woods of increasing hardness.  He names them as
   follows:  45 (common), 50 (York), 55 (middle) and 60 (half)."

   I'm not making any of this up.  What's the source of it?  Is
   there a proto-authority for it? ;-)

   Anyone with Holtapffel's book ( nudge nudge ) wanna look this
   up and report in more detail on what he's going on about?

   I'd really like to get to the bottom of this.

   Doug Dawson
   dawson@p...