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Boyd 3.0" NPSM Loose CNC Machined Aluminum Cap

Boyd 3.0" NPSM Loose CNC Machined Aluminum Cap

Availibilty : Typically In-stock, Additional QTY's available Contact us

10 in stock


Regular price $48.75
Regular price Sale price $48.75
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Shipping calculated at checkout.
Cap Vent Option

-Material =  CNC Machined 6061 ALUM
- Threads = 3” NPSM  Loose 8TPI
-Vented= Yes/ No  Based on your selection
-Lanyard = Yes, Stainless Steel 8” W Alum Crossbar
-Gasket = FKM VITON
This Cap Will only Fit our 3.0" NPSM Neck

Overall height when using our 3.0" NPSM Neck 1.5" Long will be 2" overall with the cap threaded all the way on.

SEE SKU # 81039 FOR THE NECK. Shop Neck Here

NOTE:  THE VENTED VERSION OF THIS CAP IS SIMPLY A MACHINED GROOVE THAT BYPASSES THE GASKET IT WILL LEAK WHEN LIQUID SPLASHES AGAINST IT.  It's recommended that you choose a NON Vented cap and utilize a fitting on the tank as your tank vent.


What does NPSM Loose Mean?  NPSM stands for National Pipe Straight Mechanical.  Loose means that we machine these on the higher end of the tolerance to account for Weld distortion to the neck and expansion and contraction throughout the seasons.  

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Customer Reviews

Based on 5 reviews
brandon lee
Boyd caps

Not only are boyd caps very nice as far as fit and finish. They are always on top of getting shipping out the door fast.

Brett Roberts
Just as described

My Part is beautiful! Couldn’t be happier. Thank you!

Jim Gewinner

The cap looks very nicely produced, but the finish on the aluminum is dull (like a hardware store mill finish). Expected a nicer polish or machined finish for the cap.