CMP Global Zinc Propnut Anode G-Style 1-3/4" Shaft - ZPN-GZ
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The CMP Global ZPN-GZ Zinc Propnut Anode is a zinc-only replacement sacrificial anode designed for compatible G-style propnut assemblies on marine propeller shafts. It installs over the existing propnut hardware to help protect underwater running gear from galvanic corrosion in saltwater or brackish-water service.
This anode is intended to sacrifice itself before more expensive metal components such as propellers, shafts, nuts, and related running gear are attacked by corrosion.
Key Features
- CMP Global zinc replacement propnut anode.
- Part number: ZPN-GZ.
- Designed for compatible G-style propnuts.
- Fits 1-3/4 in. propeller shaft applications where the G-style propnut assembly is used.
- Zinc-only replacement anode.
- Intended for saltwater and brackish-water corrosion protection.
- Mil-spec zinc anode material reference: Mil-A-18001.
- Designed to install onto existing compatible propnut hardware.
- Helps protect bronze, stainless steel, and other underwater metals from galvanic corrosion.
- Suitable for commercial, recreational, and industrial vessel running gear where this size and style are specified.
Technical Specifications
- Part number: ZPN-GZ
- Material: zinc anode material
- Application style: G-style propnut anode
- Target shaft size: 1-3/4 in.
- Length: 3.5 in.
- Weight: 2.5 lb / 1.13 kg
- Water type: saltwater and brackish water
- Replacement style: zinc-only anode for existing compatible propnut hardware
Propnut Compatibility
Common application context includes vessels using a compatible G-style propnut on a 1-3/4 in. propeller shaft, including:
- Inboard propeller shaft assemblies.
- Commercial vessel running gear.
- Recreational boat propeller shaft protection.
- Industrial and workboat shaft-line applications.
- Propnut anode systems requiring a zinc-only replacement element.
Use this anode only where the propnut style, shaft size, anode length, and mounting hardware match the existing installation.
Fitment Notice
Confirm compatibility by shaft diameter, propnut style, existing anode shape, mounting hardware, and clearance around the propeller nut before ordering. This is a replacement zinc anode only and is intended to fit a compatible existing G-style propnut assembly. It is not a complete propnut hardware kit unless specifically supplied that way.
Zinc anodes are best suited for saltwater or brackish-water use. For primarily freshwater operation, confirm whether magnesium or an aluminum-alloy anode is the correct choice for the vessel and water chemistry.
When This Part Needs Replacement
Replace the anode when it has worn to approximately 50% of its original size, has become loose, heavily wasted, cracked, missing, painted over, or no longer making clean electrical contact with the propnut assembly. Inspect shaft and propnut anodes regularly during haulout, diver service, or seasonal maintenance.
Uneven or unusually rapid anode wear may indicate stray current, bonding issues, mixed anode materials, or poor electrical continuity.
Installation Notes
Clean the propnut sleeve and the inside contact surface of the anode before installation. Remove paint, scale, marine growth, oxidation, and corrosion residue so the anode has direct metal-to-metal contact with the propnut assembly. Poor contact can prevent the anode from protecting the running gear properly.
Install the anode securely using the correct existing hardware. Do not paint the anode. After installation, confirm that the anode is tight, aligned, and clear of the propeller and surrounding running gear.
Alternate / Cross-Reference Part Numbers
- CMP Global ZPN-GZ — primary part number
- ZPN-GZ — zinc-only G propnut anode reference
- G-style propnut zinc anode — product description reference
- 1-3/4 in. shaft propnut anode — application reference
Parts Desk Insight
Propnut anodes protect best when they are clean, tight, and electrically connected to the hardware they are protecting. Paint, marine growth, loose mounting hardware, or the wrong anode material can reduce protection. For saltwater use, zinc is a common choice; for freshwater, confirm the correct anode material before installation.
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.