Compatible Machines & Assemblies
The Graco 100186 Internal Tooth Lock Washer appears across multiple Graco product families. Below are common assemblies/models where this washer is called out in Graco parts manuals. Always confirm with your machine’s specific parts list before ordering.
- GrindLazer™ Scarifiers — drum & cutter assemblies (Standard/various models).
- Merkur® Spray Packages — wall & cart mount package brackets and mounts (e.g., model ranges 233896–233910).
- Orion® Piston Pumps & Spray Packages — wall/cart mount packages (e.g., 234087, 234089, 234091, 234093) air/control brackets and mounts.
- Predator™ Proportioners — air control manifold/mounting sub-assemblies.
- Reactor® E-30i / E-XP2i (selected integrated proportioner assemblies and brackets).
Part Overview
The Graco 100186 Internal Tooth Lock Washer is a serrated inner-diameter lock washer designed to resist loosening from vibration. The internal “teeth” bite against the mating surface or fastener head, improving retention in high-vibration applications common to airless sprayers, proportioners, and surface-prep equipment.
| Attribute | Details |
| Graco Part # | 100186 |
| Type | Internal Tooth Lock Washer (serrated I.D.) |
| Typical Usage | Bracket mounts, air control panels, drum/cutter stacks, electrical/grounding fastener stacks, and other vibration-prone joints. |
| Typical Size Callout (example) | Appears as 5/16" I.D. in certain Graco package/manual callouts (verify your model’s diagram). |
| Interchange/Notes | Use only where your parts list specifies 100186; do not substitute external-tooth or split-lock types unless the manual permits. |
Installation & Good Practice
- Seat the washer so the teeth face the surface you want to grip (usually under a screw/bolt head or nut).
- Do not over-torque: tighten to the torque spec shown for the specific fastener in your manual.
- Replace if teeth are worn, flattened, or rusted; a fatigued washer loses bite and vibration resistance.
- Keep mating surfaces clean and dry to maximize bite and prevent fretting.
Frequently Asked Questions
The locking serrations (teeth) are on the washer’s inner diameter, gripping the fastener head/nut and the mating surface to resist loosening from vibration.
It fits any Graco assembly that explicitly lists 100186 in the parts diagram. Check your model’s Repair/Parts manual and confirm the quantity and fastener size next to the callout.
No. 100186 is an internal tooth style. Do not swap styles unless your manual approves—different lock styles behave differently under vibration and torque.
Size can vary by assembly. Some Graco package manuals list it with a 5/16" fastener stack. Always match the fastener size specified for your machine’s callout.
Ensure clean contact surfaces, seat the washer flat, tighten to spec, and re-check torque after the first use cycle. Replace worn washers rather than reusing.
