I Just went past Asutin's Dive shop looking for a shaft for my custom gun build. has anyone had any experience with Wong's new line of shafts? They are spring steel and have some sort of plating. They are pretty cheap as far as shafts go about 30 dollars cheaper than an equivalent Riffe shaft. Also from the other builders out there how well will a 7.5 mm shaft shoot through a 5/16 track? I know some builders will use an oversized bit for extra clearance.
Thanks
When you refer to track do you mean open or ET ? I've used coated spring steel shafts but not DW's.
If you don't mind the wash and dry after the hunt they are less expensive, harder to bend then 17/4 ph.
Cheers, Don
Are these the same shafts that Florida Freedivers was selling for a while as "KJ" shafts? I think they're the same shafts made in the same factory in SA.
My experience with them is that they aren't completely deburred everywhere, so the mono loop through the sharkfin can get chewed up after just one trip.
That said, I only bought one shaft, so my results might not be typical. Also, for what it's worth, I bent the hell out of the shaft, but while it was straight, it shot like a dream due to the extra rigidity vs. 17/4.
Sorry I meant an ET. I have not problem with taking a little extra care with my gear and Im sure DW' product is as good as any in its class.
Thanks Don
There are allot of Spring Steel shafts out there. It used to be that Cor-Sil was common, C1085 wire, Sae9254,
9260 and 9259 are just a few. Rust preventive coatings and plating process vary as well.
I just have no idea what DW uses, but I would image he did his research, 17/4 SS is getting very expensive these days so that may also be part of his motive.
Cheers, Don
Wong shafts are identical to the "KJ" Shafts sold at FL Freedivers. I snapped a 9/32 wong shaft and he offered to pay for a replacement. Mr. Wong is a stand up guy and backs his gear 100%. I noodled my KJ shaft soo bad it looks like a corkscrew...lol
All common iron based alloys have about the same spring rate, called Young's Modulus, and will deform about the same amount under the same load. What is different is how far they will deform before they take a permanent set.
Edit -
I did a quick test, just to see if that theory would hold.
On the left is a 9/32" stainless shaft, with a measured diameter of 0.280". On the right is a 7.5mm spring steel shaft, with a measured diameter of 0.292".
Stiffness of shafts is proportional to diameter to the fourth power. So the spring steel shaft "should" deflect a little bit less by virtue of its larger diameter. (0.280/0.292") to the fourth power is 0.85. So the spring steel shaft "should" deflect about 85% as far.
The stainless shaft deflected 5-1/2", and the spring steel shaft deflected 4-3/4", wich is 86%.
The word is that DW coated shafts rust quickly. I'm only repeating what I've been told, albeit by a reliable source, as I wouldn't bother with non stainless steel shafts and so have no experience with DW shafts. Then again there can be batches of shafts with different characteristics, so it depends which production of the same line of shafts you're getting, maybe the problem was since addressed. This thread is a reminder to get off my butt and stock some full size sharkfin tabbed shafts.
Jeff, thank you for that test. So if the stainless steel shaft was 7.5mm they'd bend the same?
Jeff, thank you for that test. So if the stainless steel shaft was 7.5mm they'd bend the same?
Right.
This confirms what I've been saying for a while now; that when I straighten a bent coated shaft it doesn't seem to require any more force than a stainless steel shaft. Will you please explain again in simple words what guys who say that coated shafts are more bend resistant are actually experiencing?
Assume that I have two shafts (one stainless, and one spring steel) that are identical in every way except for the material.
If I hang the same load on each shaft, as in my experiment, they will bend the same amount. But only up to a point.
As the shaft is bent, the steel itself is stressed, and the further the shaft is bent, the higher the stress in the steel. As long as the stress remains below a certain point, called the "yield stress", the shaft will go back to its original shape when the load is removed. If I bend the shaft until the stress in the steel exceeds the yield stress, then the shaft will stay bent, and will not return to its original shape when the load is removed.
Different steels have different yield stress, and spring steel has a higher yield stress than 17-4 stainless (generally). What this means is that I can put a heavier load on a spring steel shaft, and though it will continue to bend, it will still remain below the yield stress and will go back to the original shape when the load is removed.
So basically there is no advantage to the coated shaft other than that they are cheaper?
The advantage to a spring steel shaft, depending of course on the type of spring steel, is that it can withstand greater stress than a stainless shaft while still remaining in the "elastic" range and returning to its original shape when the load is removed.
Thanks tin I was going to give Dan a little talk, Now I can sip on my after dinner martini with out having to type.
:D:thumbsup2:
Cheers, Don
Enjoy your martini Don 
It's interesting to consider which fish will put the exact amount of stress on a shaft, that falls within these brackets; from the point where a SS shaft exceeds the yield stress, to just before a coated shaft exceeds it. To me it seems the window is too small for it to happen often and it's mostly hype. I mean a 20lb grouper that will hole up after being shot may bend whatever shaft.
Xan, the way I see it all shafts will bend. I just straighten them. Once thing I can't be bothered with is rust, so I'll pay another $20 for a shaft.
Dan, tomorrow our after dinner topic will be Hastelloy C and sea water.:D;)
Cheers, Don
I never purposefully clean or treat my SS shaft and knife to prevent rust. I do rinse my speargun because when I leave it salty I don't like how it feels when I handle it at home. I never had rust problem with shaft or knife.
This was the hot ticket for me in the late 70's, but big grouper bent them just the same, of the ten I made I only have one left.
Cheers. Don
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