http://playrustwiki.com/wiki/Server_Commands
conditionloss.damagemultiplier "amount"
Sets the time it takes for used items to lose durability. (1 = default, 0.0 = no durability loss)
conditionloss.armorhealthmult "amount"
Sets the time it takes for items to break from taking damage. (.25 = default, 0.0 = no durability loss)
Donc
conditionloss.damagemultiplier "0.0"
et
conditionloss.armorhealthmult "0.0"