If that were the case, machine tools would be made primarily from steel. They aren't. As for the hardness of cast iron, true it is softer than steel but it's high carbon (graphite) content tends to make it somewhat self lubricating were steel will gall much easier. This is, of course, metal to metal contact so really wouldn't apply here. Should have said that in the first place. As far as stability. No steel will outdo cast iron if properly stress relieved.
infrequently.
Interesting. Shows I don't know my vintage tools too well!
Any suggestions for sources. Now that Shepherd is out of business, I might be looking elsewhere for one at some point.
How is its mass compared to a heavy wood?
Did that on a shoulder.
Oh, I don't know. I'm building a steel sided smoother (Spiers inspired plane from Shepherd), and like having the dovetails disappear unless you get them in just the right light.
Well, I have to defer to you there; I know nothing about machine tools. But might there be other reasons for using CI, even if it were not as resistant to abrasion as steel?
If _what_ were true?
Large beds for metalworking machines are typically made from cast iron for a number of reasons. The primary reason is that it is possible to cast the large parts from cast iron. While there are cast steels, they don't cast as well as iron. For an appreciable number of units, casting is almost always the cheapest way to make them
Secondly, cast iron machines easier that steels due in part to the lubricity provided by the graphite inclusions mentioned above, and partly because it is softer than steel.
Cast Iron is just as stiff as steel but has better dampening, again due to the graphite inclusions.
It's good stuff.
But it is not harder or more stable than annealed steel.
What's a "bed" though? Something like a milling table is typically cast iron, but slideways on a lathe bed will be steel. Often these are steel strips attached to a cast iron bed, then machined. The iron is cheap to form and gives a stable bed, but it's worth using steel for the wear surfaces.
They cast fine (in terms of end results), it just costs more owing to the higher temperatures needed. Also most "cast steel" isn't cast (in this sense) it's just a label for a crucible steel that has been melted. Inconsequential these days, but that used to be a mark of quality over shear steels.
BTW - If anyone isn't familiar with the history of machine tools, then reading a copy of LTC Rolt's "Tools for the Job" is highly recommended.
Bristol Designs used to do them and I think Charles still has some castings, but I know that he can't source adjusters (Norris style) to offer any them more.
You can always make your own. It's not hard to get bronze castings made from a pattern, and it's not even a hard pattern to make. I'm tempted to cast my own (I've been doing a lot of bronze and silver casting lately), but I've no real need or time for one. I've got castings for an iron smoother (A5 style) and 1" shoulder plane that have been sitting here for the last 2 years already!
Corian is about 1.6 specific gravity, AFAIR. Comparable to dense-ish wood. Neither really matters anyway, a cast sole easily outweighs them.
Or if you don't want to use a casting, here's a great photo documentation of Gary Kramer's building of a box mitre plane:
That has been established.
or more stable than annealed steel. If we keep this thread going long enough, you will do a complete 180. You stand at about 140 now. I've been machining this stuff for 20 years now. Using machines to make machines. I have a pretty good idea what works and what doesn't. Did some Stellite today. Want to know some tough Sh*t.
Many people have mentioned weight as being an advantage for an infill plane. As best I can tell, rosewood species (this seems to be a common wood for infill planes) have a specific gravity of somewhere between
0.8 and 1.2. Cast iron has a specific gravity in the 7-8 range, which would make it much denser than rosewood.So does an infill plane really weigh more than a similarly sized cast iron plane?
If you filled a cast iron plane in with wood, you'd have a (heavier) infill. I imagine if someone were to fill a plane with cast iron you could still call it an infill, and it'd still be heavy.
:)
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dovetailed one (brass sides).
I'm also just off the phone from someone trying to sell me a Bridgeport vertical mill for £600.....
Yes - but because there's more metal in there, not because of the wood. Cast infills are notably heavier than dovetailed sheet. A "Plane o Ayr" is a real lightweight in comprison to anything, including a #4, because of the thin base and the minimal sides.
Remember that the infill pre-dates the Bailey pattern. They were heavyweight in comparison to woodies. The Bailey pattern was a way of giving the iron base and mass of the infill, with modern production methods and without all the expensive labour of fitting the infills. Infills still worked better though and so the myth grew up that even more mass had to be a good thing, just because one of their properties was extra mass.
Patrick is just _wrong_ when he claims this for the #4 1/2
"I have this half-baked, semi-baked, even fully-baked theory that Stanley offered this plane as competition for the heavier infill planes, being produced in England."
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