I mean you had flanged wheels, round boilers, pistons, hitches,
whistles etc.  I would guess these parts were molded.  But then a mold
had to be made--pretty big ones.  And can you make a mold without
machining?  Did the Industrial Revolution know how to machine such
molds? I would guess they had big furnaces for heating large pieces of
metal, yes?  Could they thread a bolt or nut--for without those how
did they fasten parts together?  Hope many will comment, or that there
are sites that really get into answering my questions.

In addition to comments, here are few links to explore:


The era of the steamboat began in America in 1787 when John Fitch
(1743-1798) made the first successful trial of a forty-five-foot
steamboat on the Delaware River on August 22, 1787,
http://inventors.about.com/library/inventors/blsteamship.htm

 making weapons (as usual) was pushing the envelope: 

Model 1792 rifle manufactured at the US Armory at Harper's Ferry. 
Instead of individual hand-crafting by a blacksmith/gunsmith, rifles
were made with machine tools and had the advantage of interchangeable
parts.
http://www.appaltree.net/aba/education/historical/1700 to 1800.htm

for specifing tools - like this 
http://www.davistownmuseum.org/pics/30202t13.jpg30202T13

This diminutive tool is a product of one of New England's most
important late classic period manufacturer's of taps, dies and  elated
tools. DATM (1999) lists S. W. Card Mfg. Co., which was located in
Mansfield, MA, as operating between 1874 - 1908

try these
SEARCH TERMS museum of technology, 1700 manufacturing


 The general history of technology timelines provide names and events,
which can be followed to find more specific details:

 timelines
             transport
http://inventors.about.com/library/inventors/bl_history_of_transportation.htm

               technolofy
http://inventors.about.com/library/weekly/aa111100a.htm


 Abraham Darby (1678 - 1717)   moulding

. He developed the process of sand molding that allowed iron and brass
goods to be mass produced at a lower cost per unit. Before Abraham
Darby, brass and iron goods had to be individually cast. Darby
received a patent for his sand casting in 1708.
http://inventors.about.com/library/inventors/blabrahamdarby.htm
 This proved  important to the steam engine industry that came later,
Darby's casting methods made the production of the iron and brass
steam engines possible.

                      First locomotive
 At that early period every part of the engine had to be made by hand,
and hammered into shape as a horseshoe was; and John Thorswall, the
colliery blacksmith, was his chief workman; and with all these
disadvantages and difficulties to contend with, Mr. Stephenson
persevered and finally completed his first locomotive.


After ten months' labor, this locomotive was completed and put upon
the Cillingwood Railway on the 25th July, 1814, and tried.

http://inventors.about.com/library/inventors/blrailroad7.htm


Outline of Railroad History
Designed and built by Peter Cooper in 1830, the Tom Thumb was the
first American-built steam locomotive to be operated on a
common-carrier railroad.

http://inventors.about.com/library/inventors/blrailroad.htm#george

Inventors The History of Steam Engines 
 Inventors: Thomas Savery, Thomas Newcomen, James Watt

headgie

Appreciate the leads but they didn't answer my question in the detail
I was hoping for. I feared that might be the case because though today
we can see manufacturing proesses in operation, we can't go back to
1790 or l800 and see them--or talk to engineers.  And such minute
detail as I would like is often simply unavailable on the net. But I
do thank you.

Casting of any shape starts with a wooden full size model. In the case
of bronze boat fittings, and I am sure it would also apply to iron
castings, the wooden plug is used to make a hollow 'shape' in foundry
sand. The molten metal is then poured into this hollow. The metal
hardens and the sand mould is removed. The late 19th and early 20th
centuries saw huge bronze propellors cast. They are one of the main
targets for sunken ship salvors.

When the first railway engines were manufactured after 1804 (Richard
Trevithick's locomotive), there had already been an industry
specialized in making stationary steam engines for 90 years. Since
1712, steam engines were in use in mines. So the engineers did not
have to start from zero for making locomotives; most necessary tools
for making steam engine parts had already been developed over the
previous nine decades.

Scriptor

Nuts and bolts had been in use for about 300 years before the
industrial revolution.  They were hand made though, and getting a nut
and bolt that fitted each other was as much luck as judgement - the
Industrial Revolution had been going for almost 50 years before it was
possible to machine produce them.  Even then there were no standards
for the threads - they didn't arrive until the 1840s.

Ian G.