The Wrench is the default melee weapon for the Engineer. It is a black grease-monkey wrench. This weapon does 55-75 damage, usually 65. A mini-crit will do 88, and a critical hit will do 195. This can make buildings build at twice the rate if a engineer left his building to build itself alone if you strike it while building. This can upgrade buildings to a max of level 3, gives 25 metal to a building per strike, and repairs about 60 damage a strike if the building is wounded. For sentries, it will restore about 50 ammo and 3 rocket salvos  per strike, each bullet costs 1 metal, and each rocket salvo costs 2. The swing rate is every 0.8 seconds, and is a engineer's usual defence against spies.