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3/8 in. Dia. x 3-1/2 in. L Bolt with Large Flat Washer Kit for Dock Float Drum Installation (12-Pack)

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  • Manufactured to preserve frame edges and float flanges
  • Large washer features a 7/16 in. hole to fit 3/8 in. bolt
  • Small washer helps keep the dock bottom lip protected
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Product Details

About This Product

Make sure to have the right fasteners for your aluminum dock when installing the floats. These bolt kits are designed to protect the edges of the aluminum frame and the polyethylene flange of the floats. The 1.75 in. large flat washer has 7/16 in. hole to fit perfectly on the 3/8 in. hexagonal bolt.


  • Super-sized flat washer will protect the flange of the float from the lock washer and spread the stress of the bolt on a larger surface, protecting the float's integrity
  • Smaller washer will prevent the aluminum dock bottom lip from being crushed by the bolt's head
  • Lock washers and nut will secure the whole assembly
  • Get the right combination without having to mixed flat washers with different hole sizes to achieve a stable attachment
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Product Information

Internet # 313689534

Model # 22203

Additional Resources

Shop All Multinautic


Dimensions: H 3.5 in, W 1.75 in, D 1.75 in


Product Depth (in.)

1.75 in

Product Height (in.)

3.5 in

Product Length (in.)

1.75 in

Product Width (in.)

1.75 in


Dock Hardware Type


Duty Rating


Marine Supplies Product Type

Other Marine Hardware


Galvanized Steel

Product Weight (lb.)

0.15 lb



Warranty / Certifications

Manufacturer Warranty

1 year

Questions & Answers

Typical questions asked about products:

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  • What are the dimensions of the product?

Customer Reviews

3 out of 5

  • 3 out of 2 reviews
  • 0% recommend this product
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Showing 1-2 of 2 reviews
The bolts washers & nuts were what I needed but the packing for shipment was terrible. The package broke open in the shipping box and I only had 10 bolts 11 of the larger washers 10 lock washers and 10 nuts. My project only needed 10 and so I went on and completed it as it would have taken to long to try and do a return and have the same problem getting a new package of bolts.
Response from MultinauticMar 29, 2024
Hello John,
Thank you for having taken the time to give us your feedback. Although we are happy that the bolts and parts were what you required, we are disappointed that the package arrived damaged. All items leave our facilities in a well-packaged manner, but unfortunately the boxes sometimes get bounced around while in the transport companies' trucks. We work hard to make quality products, so we are not happy to hear that your total experience was negatively affected by a logistics issue. Would you be able to send us photos of the box, so we can see how we can address the situation to prevent a re-occurrence? Our email address is Info@Multinautic.Com. Our phone number is 1-800-585-1237, ext. 218 if you wish to speak with us. Should you or anyone reading this ever need missing parts or have questions, we are always available to help. Sincerely, Peter; multionline
  • Verified Purchase
This bolt/washer combo pack for attaching multinautic floats to a...
This bolt/washer combo pack for attaching multinautic floats to a floating aluminum dock. Combo pack included all parts for 12 attachment points. Not cheap, but worked well with the doc and floats.
Response from MultinauticApr 6, 2021
Hi, we are happy to see that you loved our hardware. Thank you very much for the good review. multionline
  • Verified Purchase
Showing 1-2 of 2 reviews