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3-16/18" Hex Nut 6541-689 - Bubbles Supply

3-16/18" Hex Nut 6541-689

Part #: 6541-689

$0.99
In stock β€” ships today
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πŸ”’ Secure checkout↩️ 30-day returnsβœ… 1-year warranty
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1-year warrantySame-day ship before 3pm CTPerfect Fit Guarantee30-day returns

About this hardware/other

This 3/16-18 hex nut is an original equipment manufacturer (OEM) hardware component designed for Sundance Spas systems. This precision-threaded fastener features standard 3/16-18 threading and provides reliable secure connections for various spa components and assemblies. As genuine Sundance hardware, this hex nut maintains the exact specifications and quality standards required for proper system operation.

At Bubbles Supply, we guarantee this OEM hex nut delivers an exact fit for your Sundance spa with our comprehensive 1-year warranty backing every purchase. Our same-day shipping ensures you'll receive this essential hardware component quickly to complete your repair or maintenance project. Whether you're securing pump assemblies, mounting brackets, or other spa components, verify thread specifications match your application before installation to ensure proper fit and function.

Exact part number

6541-689

Save this for ordering or warranty claims

Also known as / Replaces

This part replaces or is interchangeable with:

  • 3/16-18 hex nut
  • hex nut 6541-689
  • Sundance OEM hex nut

Looking for an older part number? Check our supersession lookup tool

Common symptoms this part fixes

If your spa is showing any of these signs, this part is likely your fix:

  • Loose or vibrating component assembly
  • Stripped or damaged fastener requiring replacement
  • Leaking connection point due to failed hardware
  • Component mounting failure caused by degraded nut

Not sure if this is your problem? Try our diagnostic centre or .

Before you buy β€” quick checklist

  • Confirm the thread specification on your existing nut or mating bolt is 3/16-18 before ordering
  • Inspect the mating bolt or stud for thread damage β€” a new nut on a damaged bolt will not seal or hold correctly
  • Verify this is the correct hardware SKU for your specific Sundance model by cross-referencing your spa's parts diagram or service manual
  • Check whether a washer or other hardware is also required for your repair β€” this listing covers the nut only

Reading the checklist now prevents 90% of returns. Worth the 60 seconds.

Install difficulty: Easy β€” DIY-friendlyTypically 5-15 minutes

Warranty

1 year manufacturer warranty against defects

Covers manufacturing defects. Does not cover improper installation, normal wear, or accidental damage.

Warranty claims: warranty@bubblessupply.com

Perfect Fit Guarantee

Ordered with our help and the part doesn't fit? Contact us before installation. We'll resolve it with an exchange, replacement recommendation, or return approval.

Learn about our Perfect Fit Guarantee β†’

Shipping

We ship across the US and Canada. US orders ship from our US warehouse to US customers; Canadian orders ship from our Canadian warehouse to Canadian customers β€” no cross-border shipping, no surprise duties. In-stock orders placed before 3pm CT ship same day. Standard shipping $9.95 flat rate. Free shipping on orders over $200. Express options available at checkout.

Returns

30-day hassle-free returns on unused parts in original packaging. Contact us before returning to receive your RMA number.

Frequently asked questions

Check the Compatibility section above to confirm fitment for your spa brand and model. If your model is not listed, use our fitment selector at /pages/find-my-part or ask our parts AI for a personalized recommendation.

In-stock orders placed before 3pm CT ship the same day. You will receive tracking information by email as soon as your order ships.

We accept returns within 30 days of delivery for unused items in original packaging. Email returns@bubblessupply.com with your order number to start a return. Installed electrical parts cannot be returned for safety reasons.

Yes, all new parts come with a 1-year warranty against manufacturing defects. Warranty does not cover damage from improper installation or normal wear and tear.

Customer reviews

AI Fitment Assistant

Tell us your spa model and we will confirm this part fits before you buy.

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