The idea behind TTY is that the fastener is stretched to the elastic limit of the metal. (the elastic limit is the ammount something can be stretched and still return to its original dimensions when the force is removed) The problem with reusing TTY bolts is that although they return to their original dimensions when removed the metal is stressed and tightening them to TTY again will possibly result in distortion and/or weakening of the fastener.
For their purpose the waterpump bolts will liikely never have a problem if they are reused. But if you were to reuse a TTY bolt that is used for a high load application like a connecting rod cap, main bearing cap or cylinder head then you might have a problem.
Last edited by JSmith; 12/20/03 11:57 PM.
