This makes sense. And no problem about the mistranslation, this is how we learn. :+1: :beer:

[video:]Beavis And Butthead - Boing! - YouTube

@Enderman, yes, you want compressible enough springs, not too stiff. Beryllium copper 38% IACS is good in that regard. In fact, phosphor bronze and beryllium copper 38% IACS are quite good in this regard.

However, as seen by djozz in his test, springs that collapse are a problem when looking for higher conductivity, as they collapse quite easily. This is not in relation to stiffness, but elastic memory when being compressed.

We want spring with good elastic memory.

Stiffness Elastic memory goes in an increasing manner:

Copper < Beryllium Copper 45% IACS < Phosphor Bronze B-2 15% < IACS-Beryllium Copper 38% IACS ≤ Phosphor Bronze B-2 19% IACS < Stainless steel

Edit: Haha I absolutely love Beavis and Butthead. Such a great show :+1:


I made a mistranslation again. By stiff

Beryllium copper IACS 38% is a good material for a spring in terms of stiffness, and is the best balance between electrical conductivity, cost, and elastic memory. Phosphor bronze is a bit cheaper, but we already these in most sizes. A tall, not short high current spring is what’s lacking.

Well, besides a nice laugh I've had after discovering the title of hIKARInoob's linked video (to my Spanish native speaking mind that sounds :-D “moñoñoñoñoñoño”), I have an interesting question in this regards fellows: What is the relative hardness of these spring alloys versus the hardness of the usual standard carbon steel cutting pliers are usually made of? You know, if the allow is slightly softer it can be of cutting edge :-D help.

Cheers ^:)

It would be interesting to make it narrow for reverse mounts. By reverse I mean that the thick end touches battery. Lone Oceans does so to gain more space on his drivers.

Well, guys, we may have a problem.

Most of the Chinese companies got back to me, and they said that while they said Beryllium Copper 38% IACS is not much more expensive than phosphor bronze, they would have to order separetely the material, and for 200 pcs, it would probably exceed my original price point.

The only way I could get them at a reasonable price would be at onne of thr companies which sells 1000 pcs of them for 350$ everything included, since it is a custom order

Now, that would be a bit overkill. Even a group buy would be hard pressed to sell all of these units, and I do not have enough hobby money to afford all of that, and space.

So, unless someone, or many people, are willing to split the difference, I don’t think the group buy is going to be successful.

So it is a bit problematic.

Just as well. Beryllium is a nasty metal, I’ve had to use it in aerospace applications (mostly the oxide beryllia BeO for it’s thermal properties, with tight control throughout the lifecycle), but it is not something to be used ubiquitously.

It used to be used in solid rocket motors, but that was insane.

“Formation of BeO from beryllium and oxygen releases the highest energy per mass of reactants for any chemical reaction, close to 24 MJ/kg”

I doubt there is any danger in spring wire, but other alternatives are available with decent design.


I know Beryllium from the aerospace application as well, due to stupid high specific E-modulus. Odd this is not mentioned in the osha link.

The problem is the quantity.

Do you think I should make an group buy interest page for the Beryllium Copper Springs in the same size as the Djozz springs? They can handle twice the current, so they could be a replacement for spring bypasses.

If I can have enough interest in enough springs(at least 500 springs to be sold) then I will consider making the order.

My springs had a base diameter of 10mm, that was just a bit too wide for a standard tailboard, I would suggest a 9mm base diameter.

I’d buy a few :slight_smile:

You are lucky. Here are the measurements I gave to the Chinese companies:

- Material: C17530(Berrylium Copper) with IACS of 38%

- Spring upper diameter: 7mm

- Spring base diameter: 9mm

- Spring thickness: 1mm

- Spring height: 12mm

- Plating: Zinc plating/gold plating

- Total number of coils: 5

- Free length: 0 mm


I am going to make an interest list soon enough.

Maybe some retailers like MTN would be interested in getting large quantities?

I’ve also used it in F1 brake calipers. Superb, but so expensive, as for the the protection we had to use machining them … :open_mouth:

Now banned in F1, got to keep it real.

Ideal for springs though, nothing better.

Maybe you can talk to Richard at Mountain to see if he wants to buy a portion of it for his store.

Ahh that would be perfect. I did not think about Richard. He would perhaps like it. Especially now since he could sell many more springs since while the short springs are excellent, the problem is they are short.

Can the 1,000 order minimum be between two sizes?

I think 9mm base diameter is still too wide to fit onto a small board with 7135’s loaded on the same side as spring. If you could make a skinny one and one as you describe to meet the minimum that might be better

I will try to make 500 of each. Let me just update my interest post, and I will ask the Chinese company.

I’ll probably take at least 20. So for 10 lights only… I don’t think that 1000 is unrealistic number for group buy. :slight_smile:

Of course. I will add you to the list in my other post.

@djozz, how many springs are you interested in?