The Multiquip 21678 is a genuine OEM Screw Flat Head Socket Cap 5/16-24 x 1-3/4 designed for Whiteman and International walk-behind and ride-on power trowel models including CA4HC, CA5BC, J36-M30, J3036H55, CS24H55E, JS36H55, JS36H90, and B46S90. As a direct OEM replacement, this fastener meets the exact thread pitch, length, and drive specification called out in the original Multiquip parts documentation. Sourcing the correct fastener ensures structural connections stay torqued and secure during operation, preventing costly callbacks or component misalignment. DHS Equipment stocks genuine Multiquip parts so you can get the right component without guesswork.
Key Features
- Genuine OEM Thread Specification — Manufactured to the exact 5/16-24 UNF thread pitch and 1-3/4 in. length required by the original design, ensuring proper thread engagement and holding strength.
- Flat Head Socket Cap Drive — Countersunk flat head seats flush with mating surfaces, maintaining clearances on trowel assemblies where protruding fastener heads would cause interference.
- Broad Trowel Fitment — Compatible with CA4HC, CA5BC, J36-M30, J3036H55, CS24H55E, JS36H55, JS36H90, and B46S90 walk-behind and ride-on power trowel models.
- Secure Structural Connection — A correctly sized and properly graded fastener maintains the clamping load needed to keep trowel components aligned under continuous vibration and load cycling.
- Direct OEM Source — Part number 21678 matches the Multiquip parts catalog exactly, eliminating the risk of substituting an incorrect thread form or length that could back out or strip under torque.
A flat head socket cap screw is a precision fastener with a countersunk conical head and an internal hex drive, designed to sit flush or below the surface of the mating component when fully seated. On power trowels, fasteners like the Multiquip 21678 are used where a raised fastener head would obstruct movement, clearance, or the fit of adjacent parts. When a fastener of this type is missing, damaged, or substituted with an incorrect thread pitch or length, the joint loses clamping force, components can shift under load, and accelerated wear or mechanical failure of surrounding parts follows.
For help confirming this part fits your specific unit, contact the DHS Equipment parts team with your model and serial number.
Part Details
| Part Number | 21678 |
|---|---|
| Brand | Multiquip |
| Part Type | Genuine OEM |
| Description | Screw Flat Head Socket Cap 5/16-24 x 1-3/4 |
Compatibility & Fitment
| Name | Model |
|---|---|
| Whiteman Walk-Behind Power Trowels | CA4HC/CA5BC |
| Whiteman Walk-Behind Power Trowels | J36-M30 |
| Whiteman Walk-Behind Power Trowels | J3036H55 |
| Whiteman Walk-Behind Power Trowels | J36-M30 Series |
| International Walk-Behind Power Trowels | CS24H55E |
| International Walk-Behind Power Trowels | JS36H90 |
| International Walk-Behind Power Trowels | JS36H55 |
| Whiteman Walk-Behind Power Trowels | B46S90 |
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.
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