Multiquip EM991 Lock Washer 1/2 Med

The Multiquip EM991 Lock Washer 1/2 Med is a genuine OEM fastener hardware component used across a wide range of Multiquip equipment. This is a high-volume cross-machine fastener — confirmed for plate compactors including the MVC64VH, MVC82VHW, MVC88VTHW, MVH158GH, MVH208GH, MVH308GH, and MVH408GH; rammers including the MTX50HD, MTX60HD, MTX60HF, MTX70HD, MTX70HDR, MTX70HF, MTX80HDR, and MTR40HF; Whiteman mortar mixers including the WM70S/P; concrete mixers including the MC44S, MC64P/S, MC94P/S, and MC12PH; masonry saws including the MP1H, MP2H, MP2050E1, MP2050E3, MP2090HP, and MP1455HP; gasoline powered generators including the GA2.5HR, GA3.6HR, GA6HB, and GA6HEB; pumps including the QP3TH and QP402H; rollers including the MRH800GS, V305EH, and R2000H; trowels including the CA4HM and JWN24HTCSL/HSCSL; and additional equipment across the Multiquip portfolio. Sourcing the correct OEM hardware ensures the fastener delivers the correct clamping force and spring tension required for each application. DHS Equipment stocks this part and ships promptly to keep your work moving.

Key Features

• Genuine OEM Spring Tension — Manufactured to Multiquip's specified spring rate and hardness grade, ensuring the washer delivers the correct locking force for each fastened joint.
• Direct Drop-In Hardware — Sized to 1/2 Med specification for straightforward installation without adjustment or rework — threads engage as intended on the first pass.
• Broad Multiquip Fitment — Verified for use across plate compactors (MVC, MVH), rammers (MTX, MTR), mixers (WM70, MC series), masonry saws (MP series), generators (GA series), pumps (QP series), rollers, trowels, and more.
• Vibration-Resistant Locking — The split-ring design bites into mating surfaces under torque, resisting loosening caused by the sustained vibration common to compaction, mixing, and cutting equipment.
• Critical Fastener Integrity — A worn or omitted lock washer allows fasteners to back out under load — replacing with the correct OEM specification hardware maintains joint integrity and prevents component separation during operation.

A lock washer is a small but load-bearing piece of hardware that sits between a fastener and the surface it clamps. Its split-ring design creates a spring-like resistance that keeps the bolt or nut from loosening when the machine vibrates or cycles under load — conditions that are constant across compaction, mixing, cutting, and pumping equipment. Without a correctly rated lock washer in place, fasteners can back out progressively, leading to loose assemblies, misaligned components, and potential mechanical failure. Replacing a worn or missing lock washer with the correct OEM-grade part restores the fastened joint to its original holding strength.

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.