Use ball-bearing OHTLstringingequipment.com/Stringing-Blocks--Sheaves.html target='_blank'>Stringing Blocks with MC nylon sheaves (these last about twice as long). Clean and inspect them quarterly – remove debris, lubricate bearings, and repair nicks in grooves to keep friction losses to ~2% or less. Inspect blocks every ~500 conductor pulls for wear. Additionally, grounding the blocks can reduce electromagnetic interference, and upgrading to sensor-monitored blocks helps predict maintenance needs.