The Multiquip EM603 1" Lock Washer is a genuine OEM fastening component designed for the C30HD series concrete pumps, including the C30HD, C30HDNI, C30HDNI Precision, C30HDNI Zenith, C30HDG, C30HDGA, C30HDZ, and C30HDZ variants. As a direct Multiquip OEM part, the EM603 is manufactured to the same specifications as the original hardware, ensuring correct fit and function within the fastener assemblies where it is used. Confirm your model code against the fitment list above before ordering to ensure this is the right washer for your machine.
Key Features
- Genuine OEM Hardening and Temper — Manufactured to Multiquip's original material and hardness specifications, so the washer bites and holds the way the fastener assembly was engineered to perform.
- Direct-Fit Hardware — Sized at 1" to seat correctly against the mating fastener and surface without shimming or adaptation, dropping straight into the existing assembly.
- Broad C30HD Series Coverage — Confirmed for C30HD, C30HDNI, C30HDNI Precision, C30HDNI Zenith, C30HDG, C30HDGA, and C30HDZ concrete pump models.
- Maintains Clamping Force Under Load — A functioning lock washer prevents fastener back-off caused by vibration during pump operation; a worn or flattened washer allows joints to loosen and can lead to leaks or component misalignment.
- OEM Part Number Traceability — Ordering by the EM603 part number ensures you receive the exact Multiquip-sourced component, not a generic substitute that may differ in inside diameter, outside diameter, or bite angle.
A lock washer is a small but critical fastening component placed beneath a nut or bolt head to prevent the fastener from loosening due to vibration, thermal cycling, or dynamic loading. On a concrete pump like the C30HD series, where hydraulic pressures and mechanical forces are constantly at work, fasteners that back off can result in fluid leaks, structural loosening, or component failure. When a lock washer becomes flattened, corroded, or deformed, it loses its spring tension and no longer applies the friction needed to keep the fastener torqued — making routine inspection and replacement an important part of preventive maintenance.
For fitment questions or help confirming compatibility with your specific C30HD model, contact the DHS Equipment parts team directly.
Part Details
| Part Number | EM603 |
|---|---|
| Brand | Multiquip |
| Part Type | Genuine OEM |
| Description | 1" Lock Washer |
Compatibility & Fitment
| Name | Model |
|---|---|
| Mayco Pumps | C30HDNI |
| Mayco Pumps | C30HDNI Precision |
| Mayco Pumps | C30HDN |
| Mayco Pumps | C30HDNI Zenith |
| Mayco Pumps | C30HDG |
| Mayco Pumps | C30HDZ |
| Mayco Pumps | C30HDGA |
| Mayco Pumps | C30HD |
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.
