Husqvarna Washer OEM #505172901

Ensure the precise, safe assembly of your Husqvarna outdoor power equipment with the genuine OEM Washer (Part #505172901). This factory-original precision washer is a critical hardware component — placed under a bolt head, nut, or between mating surfaces to distribute clamping force evenly, protect contact surfaces from damage, maintain correct dimensional spacing, and keep fastened joints secure through the vibration and thermal cycling demands of regular outdoor power equipment operation.

Also Known As:

• Flat Washer / Plain Washer / Precision Washer
• Thrust Washer / Seating Washer / Assembly Washer

Part Number Family Context: Part #505172901 belongs to the same “505” series hardware family as Spacer Sleeve #505173301, Washer #505173001, Washer #505169801, and Shaft #505168901 — all confirmed components within the same Husqvarna handheld outdoor power equipment assembly. When servicing any one of these components, inspect the entire assembly family for wear and replace as needed to ensure a complete, reliable repair.

Key Features:

• Genuine OEM Part — Manufactured by Husqvarna to exact factory specifications for correct inner diameter, outer diameter, and thickness — the three critical dimensions that determine whether a washer functions correctly in its intended application
• Precision Load Distribution — Spreads fastener clamping force evenly across the mating surface, preventing deformation, pull-through, or surface damage that incorrectly sized hardware causes over time
• Protects Mating Surfaces — Creates a stable, hardened bearing surface between the fastener and the softer housing or component material, reducing fretting wear and extending the service life of both the fastener and the housing
• Vibration and Loosening Resistance — Maintains consistent clamping preload in the high-vibration, high-cycle environment of Husqvarna handheld outdoor power equipment, where generic hardware-store substitutes frequently compress, deform, or loosen under operational loads
• Prevents Galvanic Corrosion — Washers can serve as an insulating barrier between dissimilar metals in an assembly, preventing the electrochemical corrosion that weakens fastened joints over time in outdoor use
• Part of a Matched Assembly Family — Sequential part numbering with #505168901, #505169801, #505173001, and #505173301 indicates these components are engineered to work together within the same mechanical assembly
• Sold Individually — Order the exact quantity needed for your repair
• Direct-Fit Replacement — Manufactured to the same dimensional tolerances as the original for correct seating and function without modification

Why Genuine OEM Washers Matter: A washer that appears visually similar but differs in inner diameter, outer diameter, thickness, or material hardness can result in insufficient clamping force, fastener loosening under vibration, housing thread damage, or interference with adjacent components. Some washers are unique to the parts they are fastened to — while they may look a lot like those found in a hardware store, purchasing from a genuine OEM source is the only way to ensure they fit exactly as intended for safe, reliable operation. Husqvarna’s OEM washers are manufactured to the precise tolerances the original design requires, protecting both your equipment and your safety.

Part Details:

• OEM Part Number: 505172901
• Also Listed As: 5051729-01
• Part Type: Washer / Flat Washer / Precision Washer
• Related Parts: Shaft #505168901, Washer #505169801, Washer #505173001, Spacer Sleeve #505173301 (same 505 series assembly family)
• Brand: Husqvarna (Genuine OEM)
• Application: Husqvarna outdoor power equipment (chainsaws, trimmers, brushcutters, and related equipment)