WASHER, FLAT, USS, 1/4"Y

The Genie 6638GT is a genuine OEM USS Flat Washer, 1/4" designed for an exceptionally broad range of Genie and Terex equipment, including GS scissor lifts, S and SX telescopic boom lifts, Z and ZX articulating boom lifts, GTH telehandlers, AL and TML light towers, and a wide variety of personnel lifts, material lifts, and hoists. As a genuine OEM part, this washer is manufactured to the exact specification Genie uses in production, ensuring proper load distribution and a consistent, secure fastener assembly every time. Cross-reference part number 6638GT against your machine's parts manual to confirm fitment before ordering. With coverage spanning dozens of Genie and Terex models, this is a high-utility hardware item well worth keeping in stock.

Key Features

• Genuine OEM Material and Dimensional Spec — Manufactured to the exact outer diameter, inner diameter, and thickness Genie specifies, so load is distributed correctly across the fastener joint without risk of pull-through or surface damage.
• USS Series Standard — The USS designation means this washer follows the United States Standard series for larger outer diameters relative to the bolt size, providing broader bearing surface coverage than SAE-series equivalents of the same nominal size.
• Direct Hardware Replacement — Drops straight into any 1/4" fastener assembly where the original washer is worn, distorted, or missing, with no modification to mating hardware required.
• Exceptionally Wide Fitment — A single part number covers GS scissor lifts, S and SX telescopic booms, Z and ZX articulating booms, GTH telehandlers, AL and TML light towers, GR and AWP personnel lifts, and Genie material lifts and hoists — reducing the number of hardware SKUs you need to manage.
• Fastener Joint Integrity — A correctly sized, undistorted washer prevents fastener loosening under vibration and cyclic loads — critical in aerial equipment that operates at height and experiences repeated platform and chassis movement.

A flat washer serves as the bearing surface between a fastener — bolt head or nut — and the material being clamped. By spreading the clamping load over a larger surface area, it prevents the fastener from pulling through or damaging softer or thinner substrates, and it helps maintain consistent clamp force over time. On equipment like aerial lifts, telehandlers, and light towers, washers appear throughout structural, hydraulic, electrical, and panel assemblies, meaning a worn, undersized, or missing washer can compromise joint integrity across a wide range of systems. Replacing a distorted or corroded washer with the correct OEM-specified part restores proper clamp load and helps prevent premature fastener loosening under the vibration and dynamic loads these machines routinely experience.

Part Details

Compatibility & Fitment

Verify Before You Order

Fitment is machine-number and revision-specific; always confirm your model and serial number against the fitment list.

Why Buy From DHS Equipment

Every part is verified against the manufacturer's part number before it ships, so what you order is what arrives. We carry parts from leading OEM brands and our own DHS Quality Parts line of professional aftermarket components. Need help finding the right part? Our team is available to confirm compatibility whenever you need it. Orders are processed fast to keep your jobs on track. We don't just sell parts. We keep you jobsite ready.

Questions? Contact our team at [email protected] or 866-611-9369 — DHS Equipment is here to help you maintain peak performance.