Graco 100985 Extension Lock Washer

Graco 100985 Extension Lock Washer: Precision-Machined Stability Solution for Industrial Airless Sprayer Pumps

The Graco 100985 Extension Lock Washer is a precision-engineered retaining component designed to secure assemblies in high-pressure fluid delivery systems. Manufactured from hardened alloy steel with a corrosion-resistant finish, this washer withstands galling and deformation under repeated loading cycles, ensuring reliable pump efficiency and optimized seal longevity in industrial airless sprayer modules. Its axial preload capacity maintains bearing and seal alignment under pressures exceeding 5000 psi. Integration within a Graco repair kit simplifies maintenance workflows by reducing torque variation and stabilizing critical drive components on professional coatings equipment operating in demanding environments. It exhibits tight tolerances of ±0.01 mm on bore diameter and radial thickness, and its nickel-chromium plating resists corrosive solvents and moisture. Engineered to support torque loads up to 150 Nm, the extension lock washer optimizes vibration damping and axial stability within critical bearing housing assemblies.

• Hardened alloy steel construction with electroless nickel-chrome plating for corrosion resistance.
• Precision bore and thickness tolerances of ±0.01 mm for optimal axial preload.
• Chamfered outer edge and internal keyway profile to prevent radial runout.

The washer geometry features a chamfered outer edge to facilitate assembly under tight axial constraints and a centralized keyway profile to align with machined grooves on mating shafts. Optimized for minimal radial runout, the 100985 washer reduces the incidence of vibration-induced fatigue in dynamic sealing interfaces. Advanced finite element analysis was employed in the design phase to simulate stress distribution under cyclic loading and high-pressure filtration media, verifying accurate stress dispersion even at maximum operating pressures of 7000 psi. Tight machining tolerances of ±0.005 mm on keyway depth and a surface finish of Ra 0.8 µm contribute to reliable fitment and consistent load transfer in demanding pump applications.

Critical performance metrics include retention torque stability above 95% of initial clamp load after 100,000 actuation cycles, demonstrating exceptional pump efficiency under continuous duty. Corrosion resistance is enhanced by a nickel-chromium plating process, yielding a surface hardness of 700 HV and resisting pitting when exposed to aggressive solvent-borne coatings. Combined with optimized groove engagement geometry, this washer supports prolonged seal longevity, minimizing micro-leakage at the outer periphery of dynamic seals and thus preserving paint viscosity and film thickness consistency during high-volume spraying operations. Extended fatigue life testing has validated over 10 million cycles at 120 °C, ensuring dependable service in elevated temperature environments.

Design and Material Specifications

The 100985 extension lock washer is fabricated from high-strength AISI 4140 alloy, quenched and tempered to achieve a tensile strength exceeding 900 MPa. Precision machining ensures a bore diameter tolerance of +0.002/−0.005 mm and a thickness variance within ±0.01 mm. Surface treatment involves an electroless nickel-chromium plating that imparts excellent corrosion resistance and reduces frictional torque during assembly. The chamfered edge angle of 22° facilitates smooth insertion, while the axial keyway depth of 1.5 mm ensures positive engagement with corresponding shaft profiles.

Installation and Torque Control

Proper installation of the extension lock washer is outlined in official Graco manuals and requires a calibrated torque wrench to achieve the specified 120 ± 5 Nm clamp load. A thin film of low-viscosity, high-temperature grease applied to the washer bore and flange face minimizes galling and ensures uniform load distribution. Assembly should follow a star-pattern tightening sequence for multi-bolt flanges, verifying concentric alignment through dial indicator radial runout measurements. Routine inspection intervals, as recommended by OEM guidelines, include torque checks and visual assessment for plating degradation.

Applications and System Integration

Incorporated into the Graco UltraMax II Bearing Housing Sprayer and similar high-pressure pump assemblies, the extension lock washer integrates seamlessly according to the official graco parts list. Its universal design accommodates both rotating piston pump heads and diaphragm-seal configurations, enhancing operational stability across a range of fluid viscosities. This component’s high-pressure filtration compatibility ensures particulates are prevented from compromising dynamic seals, sustaining uninterrupted flow rates and preserving component life in demanding professional coatings environments. Additionally, the washer’s standardized profile simplifies BOM management and quality assurance within automated production lines.

Overall, the Graco 100985 Extension Lock Washer serves as a critical mechanical interface that underpins the reliability of advanced high-pressure fluid delivery systems. Its combination of hardened steel construction, precision machining, and anti-corrosion plating contributes directly to maximized pump efficiency and extended component service life. When integrated into maintenance procedures, the washer’s durability against stress and wear promotes consistent airless sprayer operation, minimizing downtime and ensuring uniform film deposition in professional coatings applications. Engineers specifying this component can rely on rigorous quality control standards and compliance with ISO 9001 manufacturing protocols for superior performance in commercial and industrial spray technology. Typical maintenance frequency is every 500 operating hours.