Mercury - Engine Mounting Screw - 10-8M2021918
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The Mercury Quicksilver Engine Mounting Screw 10-8M2021918 is an OEM structural fastener used in select Mercury/MerCruiser engine mounting applications. This screw is commonly associated with MerCruiser sterndrive engine mounting diagrams, including 3.0L Alpha One style setups, where the correct fastener length and thread pattern are important for secure engine mounting.
Key Features
- Genuine Mercury/Quicksilver engine mounting screw
- Part number: 10-8M2021918
- Also referenced as 8M2021918
- Thread size: 7/16-14 coarse thread
- Length: 4-5/8"
- Listed dimensions: .437-14 x 4.625"
- Used in select engine mounting and bracket/cradle assemblies
Engine Compatibility
Used on select Mercury/MerCruiser sterndrive engine mounting applications, including MerCruiser 3.0L Alpha One configurations where this screw is shown in the engine mounting parts diagram.
Serial Number Fitment Notice
Verify fitment by engine serial number and mounting diagram before ordering. Engine mounting hardware can vary by engine package, mount style, bracket design, and production range.
When This Part Needs Replacement
Replace this mounting screw if it is bent, stretched, corroded, stripped, seized, missing, or damaged during engine mount or bracket service.
Installation Notes
Confirm thread size, length, and mounting location before installation. Inspect the mating threads, mount bracket, engine cradle, and surrounding hardware. Use Mercury service procedures for torque requirements and any approved thread treatment.
Alternate/Superseded Part Numbers
Replaces Mercury 10-32557 and 32557.
Parts Desk Insight
Engine mounting fasteners are not ideal to substitute by length alone. The thread, grade, coating, and exact mounting location all matter because this hardware supports alignment and absorbs engine vibration.
Shipping: Ships same or next day for fast Canada wide shipping. ⚓
Shipping information
In-stock and OEM parts: ship same or next business day.
Locally warehoused items: ship within 3–4 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.