G250V Jam Nut (Flat Sided) Source

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JohnnyOTS

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Location
Phoenix, AZ USA
# of dives
25 - 49
Previous threads have discussed replacing the splined jam nut on Scubapro G250V regulators. One proposed solution was to use the jam nuts for the Halcyon Halo as a drop-in replacement.
It appears to work well.
Splined Jam Nut.jpg
Flat Sided Jam Nut.jpg


I was able to source mine through Scubadelphia - Justin obligingly created a link on their products page specifically for this jam nut. Link and comparison pictures below:


JN Comparison 1.jpg
JN Comparison 2.jpg
JN Comparison 3.jpg
 

Attachments

  • JN Comparison 2.jpg
    JN Comparison 2.jpg
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Credit for this really deserves to go to:
  1. buddhasummer for enlightening me on the joys of splinelessness
  2. geo7 for finding and sharing a reliable and helpful source
  3. Justin at Scubadelphia for making it easy to buy the parts
  4. The Vast Experience and Shared Knowledge of our fellow Scubaboard members
Thank you, one and all! :wink:
 
OOD, Absolutely.
Hose to Jam1.jpg
Hose to Jam2.jpg


Image JN Comparison 3 from my original post was my attempt to show the edge of each jam nut where they engage the o-ring. The original splined nut has a small vertical drop and then an angle inward - the halcyon nut doesn't have that vertical drop - it just angles inward. The o-ring is completely hidden when the hose is put on for both nuts.
 
I recall right that Scubapro makes the Halcyon regulators and that the parts kits can be used on either.
 
OOD, Absolutely.
View attachment 722283View attachment 722284

Image JN Comparison 3 from my original post was my attempt to show the edge of each jam nut where they engage the o-ring. The original splined nut has a small vertical drop and then an angle inward - the halcyon nut doesn't have that vertical drop - it just angles inward. The o-ring is completely hidden when the hose is put on for both nuts.
your nut looks exactly like the ones I had made. Are they made from stainless steel?
 
The Halcyon Jam nuts are not magnetic so either they're made from an austenitic stainless steel or they're not stainless steel at all.
Brass weighs more than stainless steel so I broke out the food scale (I don't have anything more precise) and got the following numbers in imperial since the scale had two digits of precision in ounces versus only one digit in grams:
Jam Nut Weights.jpg

I have one of your flat-sided jam nuts for the older G250 series so I included a comparison of that with a Scubapro splined original for the G250 as well.

The shapes are obviously different between a splined and flat sided jam nut, but based on the G250 numbers it looks like a stainless flat sided jam nut should be lighter than the chromed brass Scubapro splined. Since the Halcyon Jam Nut is not any lighter than the Scubapro G250V Jam Nut, I believe the Halcyon isn't stainless steel at all. My best guess is it's chromed brass, just like the Scubapro one is. I'm not willing to scratch one of them up to confirm that though.
 
https://www.shearwater.com/products/teric/

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