BLF Interest List: EX3 High Current Beryllium Copper Silver Plated springs - Still selling my springs :)

I’m in for-
12)-FD2 SST-20
10)–3rd gen BeCu (L)
10)–3rd gen BeCu (Sm)

Added to the list:

Did you see my test in that thread? I have an email out to Hank to see what tint bin he used for the D18. It seems to be something different than what he advertises in his store as FB4.

Either that or i’m doing something wrong with my tests.

Any 2nd generation springs still for sale? Only 4 coils in the big 2nd gen one, does that means it ends up deformed like phosphor bronze springs?


Yes, they are still available, and while not as extreme as the Fasttech phosphor bronze springs, it does go down from 12mm right down to 9,2mm.

I’m in for:
10 L BeCU v3 springs
10 S BeCu v3 springs
6 budget springs
10 FD2s

Added to the list:

Would you please add 5 big and 5 small Rev 3 springs for me in line 6? Thanks. :laughing:

No problem.

We are at 365 SST-20 FD2s!

Only 135 more needed!

Quite a few people are springing for these!


5 of each spring type and 10 sst20 please

10 SST20’s please! 5 large and 5 small gen 3 springs as well.


I may be having a daft moment but wouldn’t reversing the direction of the wind then cause gouging when removing the tailcap?

I see.
Some further ideas:

  1. You have a strong material on the inside and weak on the outside. Mechanically the opposite would be much better.
    If you started with a thin solid copper wire and then plated it with LOTS of beryllium copper, the spring would be much stronger.
    Or, better, start with a slightly thicker (but still thin) solid copper wire and plate it with a little less beryllium copper. You would retain mechanical properties while improving mechanical properties slightly.
    I know.
    This would be crazy expensive.
    What if you started with thick C17500 spring and reinforced it with 20+ µm C17530? Would that be even possible? Would 20 µm be enough to make the difference?
  2. Have you considered reducing contact resistance with the help of contact plates? Would that make sense?

Well, maybe. The reversing of the tail-cap might cause a reverse gouge. But then, when you’re loosening the tail-cap, you are also relieving the pressure of the spring against the end of the cell. So, it might not be as bad as when you’re compressing the spring.

All that aside, BlueSwordM will be making the new generation springs without a loose end to damage cells. The end will be bent inward.

I use a 30 caliber gas check soldered to my springs to prevent damage and to provide maximum contact with the cells in high current lights.

1. Your idea is nice, but wouldn’t work actually, for multiple reasons.

For the 1st reason being that it’s not necessary.
I’ve done the calculations, and asked the manufacturer, and a 25um layer radius wouldn’t affect the mechanical properties in any way.

Second reason being that plating such large thickness would not only be expensive, impractical, but also BAD, because doing such a thick layer(50um) would require multiple baths, and start introducing crystalline imperfections at over say 100um.

And you can’t actually plate Beryllium copper. Due to having different properties of metals in the solution, the metals will plate out selectively, and the properties we want will be completely wasted, and the spring would become toxic if ever sanded, unlike the current copper alloy.

Finally, starting with BeCu C17500 would result in worse mechanical properties than what I want, and plating BeCu C17530, which is impossible, would not help in any noticeable way, and would be a worse option anyway. And using a copper wire as the base would be a very bad idea for obvious reasons.

2. Would be nice, but would cost more and require additional manual labor.
Would help if it was gold plated.

TLDR: Plating copper(20-25um)+silver on a BeCu C17530 38% IACS spring is our current best bet without going for the experimental BeCu C17550 60% IACS that is stupidly and crazily expensive, and in small quantities now

@Marc E and DavidEF, that’s it.

In for 12 of the unicorn emitters.