The TMFN impact spanners are designed for safely tightening and loosening larger locknuts, especially after driving up a large bearing onto a tapered seating. Made of spheroidal graphite cast iron, they have a special impact surface allowing for optimum transmission of impact energy to the nut. SKF assembly wrenches in various sizes are designed for easy tightening and loosening of locknuts. They are used to secure and adjust bearings on tapered shafts, adapter sleeves, and withdrawal sleeves.