In case it matters, the shaft will be 5/8" dia. X 18" or 24" long (haven't decided on that yet). The drum will be made of 5" dia. MDF disks.
A question re: steel - hot rolled vs cold rolled
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A question re: steel - hot rolled vs cold rolled
I'm building a thickness sander and I need to purchase a steel rod to serve as the shaft for the drum. I can buy hot rolled or cold rolled steel rod in the size I need...but I don't know nothin about the different types of steel and why I should prefer one type over the other. Any advice will be appreciated.
In case it matters, the shaft will be 5/8" dia. X 18" or 24" long (haven't decided on that yet). The drum will be made of 5" dia. MDF disks.I rather be an American than a Republican.Tags: None -
Re: A question re: steel - hot rolled vs cold rolled
For a rod, cold-rolled is better--stronger and probably more precise in size.Goat Island Skiff and Simmons Sea Skiff construction photos here:
http://s176.photobucket.com/albums/w...esMan/?start=0
and here:
http://www.flickr.com/photos/37973275@N03/
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Re: A question re: steel - hot rolled vs cold rolled
as sold by metals shops near me:
hot rolled - cheaper, looser tolerances, more mill scale (which is a pain to remove) on the top
cold rolled - more expensive, tighter tolerances
curious what plans you are using to make the thickness sander, it's on the list of things to investigate.Comment
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Re: A question re: steel - hot rolled vs cold rolled
Hot rolled and cold rolled mild steel will be the same alloy
Cold rolled will be +.000 -.002 tolerance
Hot rolled will be no where near that.
Mcmaster Carr sells small quantities of various alloys with an introduction explaining the properties of the various alloys they sell.
You may want a better alloy than mild steel.
try this page http://www.mcmaster.com/#about-carbon-steel/=ncsodm
edit to add; I have repaired broken spindles in thickness sanders, they suffer from fatique (work hardening) at the drum/shaft connectComment
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“Travel is fatal to prejudice, bigotry, and narrow-mindedness, and many of our people need it sorely on these accounts. Broad, wholesome, charitable views of men and things cannot be acquired by vegetating in one little corner of the earth all one's lifetime.”― Mark Twain,Comment
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Re: A question re: steel - hot rolled vs cold rolled
Cold Rolled would be what you'd want for the axle of a kid's wagon. Hot Rolled is like rebar for concrete. The grain in cold rolled has been elongated by the process and is stiffer and stronger, given the particular alloy elements.Comment
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Re: A question re: steel - hot rolled vs cold rolled
The major difference in ordinary low-carbon steel is surface finish, size tolerance, and cost, although neither are very expensive. Strength is roughly equivalent. Stiffness is identical for just about every type of steel, no matter how fancy. I'd buy cold-rolled. If you're concerned about strength it would probably be more economical to just make it a larger diameter than to buy more expensive steel."For a successful technology, reality must take precedence over public relations,
for nature cannot be fooled."
Richard FeynmanComment
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I rather be an American than a Republican.Comment
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Re: A question re: steel - hot rolled vs cold rolled
If you're looking for precision - don't forget to consider ground rod stock - it's available with a variety of ends - male thread, female thread, reduced diameter, soft ends for machining, etc."The pessimist complains about the wind; the optimist expects it to change; the realist adjusts the sails."
-William A. WardComment
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Re: A question re: steel - hot rolled vs cold rolled
I guessing the only reason for using solid rod, instead of tubing, is for the key way?
Tubing would be lighter and more resistant to bending.“Travel is fatal to prejudice, bigotry, and narrow-mindedness, and many of our people need it sorely on these accounts. Broad, wholesome, charitable views of men and things cannot be acquired by vegetating in one little corner of the earth all one's lifetime.”― Mark Twain,Comment
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Re: A question re: steel - hot rolled vs cold rolled
Tubing would be lighter and more resistant to bending.
If you're putting the shaft into mounted bearings (pillow blocks or flange bearings) you can get the shaft tolerance from the bearing manufacturer. Normal spec for a 5/8" shaft is +0, -0.0005" (yeah, that's half a thousandth) although you can get by with a somewhat sloppier fit if shaft runout isn't critical. Normal tolerance on 1018 cold-rolled bar is +0, -.002, which should be fine for this application.Last edited by Keith Wilson; 06-26-2013, 01:10 PM."For a successful technology, reality must take precedence over public relations,
for nature cannot be fooled."
Richard FeynmanComment
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Re: A question re: steel - hot rolled vs cold rolled
for his application a 1" shaft at most a foot long or so would not be that much weight
it's a piece of shop equipment not an airplaneComment
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Re: A question re: steel - hot rolled vs cold rolled
For that application, a steel that will bend or flex through more cycles would be the deciding factor for me.
I spend a lot of time (and other peoples money) repairing machines that have failed due to fatique from cyclic stress.
One in particular is a certain thickness sander. The part itself is too expensive for me to manufacture versus the cost of replacing it with another "over the counter part". But if I was starting from scratch I would consider a better alloy than mild steel.Comment
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