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sprocket
Jan 25, 2003, 2:03 AM
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Registered: Jan 13, 2003
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Some of my climbing friends are persistant about using stainless bolts on climbs.I also have several mechanic friends that think galvinized ones will out last stainless.I have not done much bolting yet as I prefer
to put up traditional lines,but would like to decide which is better before I join the drill team.
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apollodorus
Jan 25, 2003, 2:33 AM
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Registered: Feb 18, 2002
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Stainless steel is going to outlast galvanized steel by a long margin.
Galvanized steel has a thin coating of zinc, which keeps moisture and air away from the steel. The zinc coating is also a sacrificial anode, which means that it oxidizes first. Basically, the two metals interact so that the zinc prevents the steel from rusting, but the steel hastens the rate at which the zinc oxidizes. The zinc oxide flakes off very easily, and when it's all gone, the steel has nothing to protect it and will rapidly rust away.
Stainless steel has a high content of chromium (and usually nickel) throughout the alloy. At the surface, very tough chromium oxide forms a protective layer. The chromium oxide does not flake off, but stays attached to the underlying metal. Even if the oxide layer is worn off, more forms immediately.
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sprocket
Jan 25, 2003, 2:49 AM
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Registered: Jan 13, 2003
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I know galvys will rust faster but dont stainless bolts snap clean where a galvy would just bend?You can coat the bolts with silicone or somthing.
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apollodorus
Jan 25, 2003, 2:59 AM
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Most stainless bolts are 304 alloy, which is one of the most ductile of all steels. Conceivably, you can cold work the 304 until it has no more ductility left and becomes brittle. However, bolts are not cold worked to that extent. They are intentionally cold-worked to increase the strength, but not so much that they become brittle.
Stainless steel knives are made from a different alloy, like a 410. This alloy has less chromium and more carbon and can be heat treated for better hardness for maintaining an edge. The harder you make it, though, the more brittle it becomes. That is why you can rather easily break stainless knives.
Another reason to not use galvanized bolts is that they are usually weaker than stainless steel.
These guys here are the experts when it comes to bolts for rockclimbing:
http://www.safeclimbing.org
[ This Message was edited by: apollodorus on 2003-01-24 18:59 ]
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copperhead
Jan 25, 2003, 3:07 AM
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Registered: Nov 26, 2002
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Stainless Rawl 5-piece.
They can eventually be removed whereas a thread-head bolt cannot.
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awsclimber
Jan 25, 2003, 3:07 AM
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Registered: Apr 18, 2002
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I checked out alpo.......'s profile becuase he seemed to know his stuff, and holy #^$&, check out these http://www.rockclimbing.com/users/list.php?UserID=apollodorus
I'm definately impressed.....you should market them!
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