Multiquip 12735 Hardened Key 3/8 x 3/4

The Multiquip 12735 Hardened Key 3/8 x 3/4 is a genuine OEM component designed for HHN and HHX series Whiteman ride-on power trowels, including the HHN31V, HHN34TVD, HHXD5, HHXG5, HHXD5-ES, HHXDF4-DF5, HHNG5, and EHHNK5. As a direct OEM replacement, 12735 meets the original engineering specification for material grade and dimensional tolerancing, ensuring a proper fit within the drivetrain. DHS Equipment supplies this part as an authorized Multiquip OEM distributor, so you can order with confidence knowing the part number has been verified against current Multiquip parts documentation.

Key Features

• OEM-Grade Hardened Steel — Manufactured to the same material hardness specification as the original, maintaining shear resistance and wear life under trowel drivetrain loads.
• Exact Dimensional Fit — Cut to 3/8 x 3/4 inch to seat correctly in the keyway without shimming, filing, or adjustment during installation.
• Broad HHN and HHX Series Coverage — Confirmed fitment across HHN31V, HHN34TVD, HHXD5, HHXG5, HHXD5-ES, HHXDF4-DF5, HHNG5, and EHHNK5 ride-on trowel models.
• Drivetrain Torque Transfer — A correctly sized and hardened key keeps the shaft and hub locked in alignment; a worn or undersized key allows slippage that accelerates damage to both mating components.
• Genuine Multiquip OEM Part — Supplied under part number 12735 directly from the Multiquip OEM parts catalog, not a generic substitute.

A hardened key is a small but critical drivetrain component that sits in the keyway between a rotating shaft and a hub or gear, locking both parts together so torque transfers cleanly from one to the other. On a ride-on power trowel, this connection must withstand continuous rotational load across the blade gearbox or drive assembly. When a key wears, deforms, or shears, the shaft and hub begin to slip relative to each other, causing vibration, loss of blade control, and accelerating damage to the surrounding keyway surfaces — making prompt replacement essential to restoring full trowel performance.

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.