Mercury MerCruiser Quicksilver Washer 20533 – Pack of 5
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Mercury / MerCruiser Quicksilver Washer 20533 – Pack of 5
Part Number: 20533 | Service Format: 12-20533 | Outside Diameter: ~9/16 in. | Pack Quantity: 5 washers | GTIN: 745061129924
Genuine Mercury / MerCruiser OEM flat washer used across a wide range of Mercury and MerCruiser engine, cooling, exhaust, electrical, and mounting assemblies. Documented applications include water-pump housing studs, exhaust-manifold hardware, ECM and electrical-box mounting, throttle-body and bracket assemblies, and legacy Mercury outboard top-cowl handle studs. Required quantity varies by assembly — the Pack of 5 is a sales quantity, not a universal per-engine requirement. Always confirm the diagram part number and quantity for your specific application before ordering.
Specifications
- Brand: Mercury / MerCruiser / Quicksilver
- Part Number: 20533
- Service Format: 12-20533
- Type: OEM flat washer
- Outside Diameter: ~9/16 in. (per legacy cowl hardware diagram)
- Pack Quantity: 5 washers
- GTIN / UPC: 745061129924
- Weight: ~0.05 kg per pack (estimate)
- Superseded By: No confirmed newer OEM superseding number identified
Compatible Applications
Fitment and required quantity must be confirmed against the Mercury parts diagram for your specific engine model and serial number. 20533 is shared hardware — appearance alone is not a reliable match.
- MerCruiser water-pump housing and cover stud hardware — qty 2 per documented assembly
- MerCruiser exhaust-manifold assemblies — qty 8 per documented assembly
- ECM / electrical-box mounting hardware — qty 4 per documented arrangement
- Throttle-body and bracket assemblies (selected MerCruiser applications)
- Legacy Mercury outboard top-cowl handle studs — qty 5 per documented assembly
- Additional Mercury and MerCruiser assemblies where 12-20533 appears on the parts diagram
When to Replace
- Washer is bent, distorted, or no longer sitting flat against the mating surface
- Center hole is worn, elongated, or damaged
- Heavy corrosion is compromising the load-bearing surface
- Washer goes missing during disassembly — keeping a pack on hand prevents delays
- Any time the assembly is opened for service and the original washers show wear
Installation Notes
- Use 20533 only where the Mercury parts diagram specifies this washer — not all assemblies use the same flat washer
- Confirm the mating screw, stud, and nut specifications before installation
- Torque fasteners to the Mercury service manual specification for the exact assembly — do not apply a generic torque value
- Replace companion fasteners (screws, nuts, lock washers) if they show corrosion or thread wear while the assembly is apart
Related Parts & Service Items
- Mercury MerCruiser Quicksilver Seawater Pump Washer 20084 – Pack of 5
- Mercury Washer 20086 (Pack of 5)
- Mercury MerCruiser Quicksilver Washer 24664 – Pack of 5
- Mercury MerCruiser Flat Washer 2-Pack — 12-44164
- Mercury Quicksilver Split Lock Washer 13-33734 — Flywheel & Engine Mount Hardware
- Mercury MerCruiser Quicksilver Exhaust Manifold End Cap Gasket 480431
Parts Desk Insights
Best use case: 20533 is a go-to stocking washer for any MerCruiser service involving the water pump, exhaust manifold, or electrical/ECM hardware. A pack of 5 is practical because the required quantity varies by assembly — having extras on hand keeps you from stopping a job over a missing washer. Order by the diagram part number, not by size alone.
Common customer issue: Assuming all Mercury flat washers are interchangeable because they look similar. Mercury uses several different washers across these assemblies that can look nearly identical but differ in inner diameter, outer diameter, thickness, and material. The part number in your diagram is the only reliable way to confirm the correct washer. If you’re unsure which washer your assembly calls for, our parts desk can help you identify the right one before you order.
Shipping information
In-stock and OEM parts: ship same or next business day.
Locally warehoused items: ship within 1-3 business days.
Special-order items: timeline confirmed after order.
Returns & warranty
Returns & Satisfaction Guarantee
We stand firmly behind the quality of every product we sell. Your confidence matters to us — and we back it with a straightforward 30-Day Satisfaction Guarantee.
If you are not fully satisfied, you may request a return within 30 days of delivery. All returns must receive pre-approval prior to being sent back. Unauthorized returns will not be accepted.
To qualify for a return:
Item must be in new, unused condition
Product must be in its original packaging
All parts, components, hardware, manuals, and accessories must be included
Packaging must be undamaged and suitable for resale
Important:
Electronics are strictly inspected. No returns on open-box electronics. Exceptions may apply only with prior written approval. Any electronic unit that has been installed, powered, activated, or altered may not be eligible for return.
We are serious about product integrity — and equally serious about taking care of our customers. If there is ever a product issue, contact us immediately so we can make it right.
For return authorization, please contact our support team before shipping anything back.