Chainsaw

They never wear out: they use their charge (charge them in a BatBox, CESU or MFE). Mining Drill: 50 EU per block, like an iron pickaxe and shovel. Diamond Drill: 80 EU per block, diamond level (mines obsidian) and twice as fast; crafted from the Mining Drill keeping its charge. Chainsaw: 50 EU per wood, leaves or wool block, 100 EU per hit (10 damage) and shears sheep with right-click. Without charge they mine like a bare hand.