Multiquip 21869 Cap Screw 5/16-18 x 5/8 Self Tap Button

The Multiquip 21869 Cap Screw 5/16-18 x 5/8 Self Tap Button is a genuine OEM fastener designed for Whiteman ride-on power trowels and roller screeds across the HTX, STX, LD, HHX, and WRS series. As a direct OEM replacement, this screw meets the exact thread specification and drive geometry of the original hardware — so it seats and torques correctly the first time. Confirmed fitment includes models such as HTX6H, HTX44K4, HTX44K5, HTX44Y4, HTX44Y5, STX6H, STXDF, LD60, HTXG6DF, HHXG5, HHXD5, HHXD5-ES, HHXDF4-DF5, WRS5200, WRS5200DFPU, and WRSPUDF. Keep a few on hand — fasteners like this are among the most commonly needed items during routine service and panel removal.

Key Features

• Genuine OEM Thread Spec: — Manufactured to the exact 5/16-18 thread pitch and 5/8-inch length spec, ensuring correct torque engagement without stripping or over-driving.
• Self-Tapping Button Head Design: — The self-tapping thread form cuts cleanly into the receiving material on installation, making panel and cover reassembly straightforward.
• Broad Ride-On Trowel and Screed Fitment: — Compatible with HTX, STX, LD, HHX, and WRS series machines, covering a wide range of Whiteman hydrostatic trowels and roller screeds.
• Correct Drive Interface: — Button head profile matches the original fastener geometry, so standard tooling seats the screw flush without clearance issues on panels or guards.
• OEM Sourced Hardware: — Supplied as a genuine Multiquip part under part number 21869, ensuring the material grade and finish match what left the factory on your machine.

A self-tapping cap screw is a hardened fastener designed to form or cut its own mating thread as it is driven into a pre-drilled or unthreaded hole. The button head profile spreads clamping load across a wider bearing surface than a standard hex head, which helps secure sheet metal panels, guards, and covers without distorting thinner material. When this type of fastener is stripped, missing, or substituted with an incorrect size, panels can shift, vibrate loose during operation, or leave internal components exposed to concrete slurry and debris — making correct replacement hardware more important than it might initially appear.

Have a question about fitment? Contact DHS Equipment to confirm this part is correct for your machine's serial number before ordering.

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.