All Murray worm drive clamps are manufactured with a small amount of lubricant on the screw.
For plated carbon steel screws the zinc plating serves as the lubricant. All stainless screws utilize a supplemental (clear) wax compound.
Regarding stainless screws, over time the wax compound may dry up or be driven off by in-service temperatures or harsh environments. This may leave the clamp assembly in a totally dry or under-lubricated state. If this clamp were to be re-used as-is, it might be found to be under-performing with regard to expected torque-tension characteristics.
Most clamps can be restored to acceptable performance levels in the field by applying a small amount of lubricant. Motorcycle chain wax, WD-40, or similar products have given good performance.Download Tech Tip