

The Graco 101390 Lock Washer (Internal Tooth) is a genuine OEM fastener designed to prevent loosening under vibration and ensure secure assembly in Graco systems.
Because this is a small internal hardware item, it may also appear in other Graco assemblies. Always verify by part number in your unit’s parts manual.
Graco 101390 is an internal-tooth lock washer used to secure fasteners and resist loosening from vibration. It is a Genuine Graco OEM hardware item commonly paired with screws/bolts on brackets, interfaces, and pump/motor sub-assemblies.
| Part Number | 101390 |
|---|---|
| Type | Lock Washer, Internal Tooth (shake-proof style) |
| Function | Helps prevent fastener back-off under vibration; improves electrical/grounding bite on clean surfaces when required by the assembly. |
| Placement | Between the fastener head (or nut) and the mating surface, as illustrated in the equipment’s assembly diagram. |
| Status | OEM Graco hardware for fit and reliability. |
| Notes | Refer to your specific model’s parts list to confirm quantity and location. |