Iron Falcon 72 Posted February 18, 2009 Share Posted February 18, 2009 Is there a good rule-of-thumb to judge how oversized a piece should be when hot so it's the right size cold? Say you want 1/2 X 3/8 finished? How much larger should it be hot? Quote Link to comment Share on other sites More sharing options...
D Ravizza Posted February 18, 2009 Share Posted February 18, 2009 Steel expands/contracts at a rate of .0000065 inches per inch per degree Fahrenheit. So a 1.0 inch long piece of steel raised 1000 degrees F would measure 1.0065. Sorry if this is more technical than you need. Hopefully someone has a good rule of thumb. Dan Quote Link to comment Share on other sites More sharing options...
Mark Aspery Posted February 19, 2009 Share Posted February 19, 2009 1/4 inch per foot shrinkage from liquid---roughly Make that 3/16 from a yellow heat. Quote Link to comment Share on other sites More sharing options...
Hofi Posted February 19, 2009 Share Posted February 19, 2009 If one calculate on 1832 degrees F the shrink/expantion factor is 1.2 % but on average forging temp which is 1500 F IT IS 1 % And those two numbers are easy to remember Hofi Quote Link to comment Share on other sites More sharing options...
Iron Falcon 72 Posted February 19, 2009 Author Share Posted February 19, 2009 Thanks all. It's a tiny amount for 1/2" but it means I'm going to have to upset the post vise wedge I just made. Drat! Quote Link to comment Share on other sites More sharing options...
easilyconfused Posted February 19, 2009 Share Posted February 19, 2009 Here I thought you meant it was cold out . Quote Link to comment Share on other sites More sharing options...
HWooldridge Posted February 19, 2009 Share Posted February 19, 2009 I seem to recall that a formula for shrinking wagon tires was 1/8 per foot. Quote Link to comment Share on other sites More sharing options...
carlson Posted February 19, 2009 Share Posted February 19, 2009 before or after swimming? Quote Link to comment Share on other sites More sharing options...
Iron Falcon 72 Posted February 20, 2009 Author Share Posted February 20, 2009 I wondered if anyone was going to respond to the rather obvious pun! Took five posts before we got one. Incredible discipline :-) Quote Link to comment Share on other sites More sharing options...
CBrann Posted February 21, 2009 Share Posted February 21, 2009 I was looking around for the expansion coeffecient of steel.. and found any where from .000006 to .000011 per degree F Assuming you could find it at all. There were a lot of tests, BTW how do you use things like the modulus of elasticity or the formaula about bending/ deformation/malleability ( Yeah I know I am kinda a mah/ physics head, besides its fun to spout big numbers during demos... ohhhs and ahhs like iron and steel are that hard) Quote Link to comment Share on other sites More sharing options...
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