Keying Shafts into Hubs for Maximum Power Transfer

  • Post last modified:October 10, 2025

The task of joining a shaft into a hub (such as assembling gears, pulleys, sprockets, or rotors onto a shaft) is crucial for transmitting power. Traditional methods rely on keys, splines, or press fits, but these methods often leave micro-gaps that allow for fretting corrosion, slip, and eventual component fatigue or failure when subjected to heavy torque and vibration. A retaining compound fills these micro-gaps, creating a 100% surface-to-surface bond that locks the components together.

INCURE WeldLock™ 365 Retaining Compound

Shaft-to-hub assemblies demand the absolute highest shear strength to resist rotational forces (torque) and prevent axial pull-out. WeldLock™ 365 is the ideal product for critical, high-load, high-speed applications. It converts even a loose slip fit into a rigid, permanent assembly that transmits maximum power without wear or micro-movement.

Feature & BenefitTechnical Insight for Shaft-to-Hub AssembliesConversion Value
Highest Strength (365)Cures to an extremely high-strength, rigid thermoset plastic, providing maximum resistance to rotational slip and heavy axial load.Zero Slippage: 
Eliminates all micro-movement, ensuring 100% torque transfer and stopping fretting wear.
High Temperature ResistanceWithstands continuous operational temperatures up to 200∘C(392∘F), essential for gear drives or high-speed pulleys that generate friction heat.End the Heat Threat: Guarantees the joint won’t fail or soften under the hottest operational conditions.
Fills Close Clearance GapsIdeal for components assembled with an interference or true close-tolerance slip fit (less than 0.05 mm diametral clearance).Maximizes Contact: 
Converts a small-gap fit into a monolithic, integrated power-transfer component.
High Chemical ResistanceInert to common gear oil, hydraulic fluid, and industrial solvents, ensuring the integrity of the joint is protected in harsh environments.Reliability Assured: 
The bond remains strong and intact, even when saturated with lubricants.

Application Steps: Locking Shafts and Hubs for Max Power

Preparation (Essential): Thoroughly clean both the hub bore and the shaft surface. Remove all oil, grease, paint, and residue. Use a degreasing solvent (like acetone or brake cleaner) and wipe until both metal surfaces are perfectly dryAnaerobic retention requires clean metal.

Application: Apply a continuous, liberal bead of WeldLock™ 365 evenly around the shaft surface. Alternatively, apply it to the inside circumference of the hub bore. Ensure the compound completely covers the mating area.

Assembly: Slide or press the hub onto the shaft. Ensure the hub is correctly positioned (axially) on the shaft. The excess compound will ooze out; wipe this away immediately.

Curing Time (Critical): Allow a minimum of 24 hours for the compound to reach full cure strength before subjecting the assembly to heavy torque, rotational speeds, or operational loads.

Alternative for Worn or Large-Gap Assemblies: If the bore-to-shaft clearance is larger (up to 0.25 mm), use INCURE WeldLock™ 356 (Metallic Grey). This compound is specifically formulated with fillers to tolerate larger diametral clearances while still providing high structural integrity.

Stop risking component slip and ensure your power transfer assemblies are absolutely permanent.