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Could I make a carabiner's pin/rivet out of copper instead of steel?
8

Could I make a carabiner's pin/rivet out of copper instead of steel?

Could I make a carabiner's pin/rivet out of copper instead of steel?

(OP)
Hi,
I am making a carabiner which won't be suitable for climbing, but designed mainly to carry keys.

In order to achieve a beautiful contrast, I want to make the pin/rivet of the carabiner out of copper.

Would that create a problem with the longevity of the carabiner? Is copper not strong enough to sustain the everyday use of a carabiner keychain?

Best,
Panos

RE: Could I make a carabiner's pin/rivet out of copper instead of steel?

Pure Cu is too soft, and it doesn't work harden much.
Maybe you could use a brass, still has some color but more strength.

= = = = = = = = = = = = = = = = = = = =
Plymouth Tube

RE: Could I make a carabiner's pin/rivet out of copper instead of steel?

Be Copper alloy would work and the color matches that of copper.

RE: Could I make a carabiner's pin/rivet out of copper instead of steel?

(OP)
Edstainless and weldstan, thank you very much for your replies!

Edstainless, actually the manufacturer suggested brass because copper wouldn't work and we are making the first prototypes with a brass pin, but the copper looks so much sexier in our 3D renders that I wanted to dig deeper and make sure he's not bullshitting me.

Weldstan, that is an amazing suggestion. One that I didn't think of. Does the copper alloy have about the same strength as brass?

One side-question for both of you guys. I was also thinking of making another version with a pin made of gold. Does gold have the same limitations as copper? And if yes, is there a way around this, like weldstan suggested with the copper alloy?

Panos

RE: Could I make a carabiner's pin/rivet out of copper instead of steel?

Electroplate steel pins with gold or copper.

RE: Could I make a carabiner's pin/rivet out of copper instead of steel?

(OP)
Compositepro, thank you very much for your reply.

One question: Since the carabiner is made for use as a keychain, meaning a lot of rubbing and grinding against coins and keys in the user's pocket. Will the electroplated pin's finish chip or fade with use?

RE: Could I make a carabiner's pin/rivet out of copper instead of steel?

All coatings will wear at high points. Even solid metal will wear. It a question of how long you want it to last (or look good) versus what your customer is willing to pay. Copper rivets are not unusual so it may very well work for your application. It will certainly work with a steel sleeve on the pin.

RE: Could I make a carabiner's pin/rivet out of copper instead of steel?

2
I'd avoid Be copper, the Be is Beryllium, which is quite toxic, and creates a higher cost for machining due to the care taken during cutting and afterwards for disposal of the scrap.

Look at alloys C18200 (chrome copper) and 145 (Tellurium copper) if you want harder, but non toxic, copper-colored alloys, and purchase them in half-hard or higher hardness.

I don't think a plated finish would hold up well, unless you could keep the head of the rivet/pin below flush with the surface. A gold color would be easier to obtain with any number of bronze/brass alloys, and hold up well to wear/corrosion.

RE: Could I make a carabiner's pin/rivet out of copper instead of steel?

Another thought - if you just care about the appearance of the head of the rivet/pin, why not use a steel roll pin (hollow tubular shape of high hardness steel or stainless steel) and pass a soft copper wire through it, then peen the end of the wire to form a rivet head that hides the roll pin under it.

RE: Could I make a carabiner's pin/rivet out of copper instead of steel?

(OP)
Compositepro, I aim for a more luxury approach, in looks as well as in price, so I would say that looking good and lasting for about a year with normal use (if there is a way to quantify and define a keychain use as normal) as a successful outcome.

btrueblood, thank you for your input. Toxicity and the higher cost are very important factors that I need to take into consideration. I'll look at the alloys you suggested. Your reply is gold.

Panos

RE: Could I make a carabiner's pin/rivet out of copper instead of steel?

(OP)

Quote (btrueblood)

Another thought - if you just care about the appearance of the head of the rivet/pin, why not use a steel roll pin (hollow tubular shape of high hardness steel or stainless steel) and pass a soft copper wire through it, then peen the end of the wire to form a rivet head that hides the roll pin under it.

Besides the appearance, I do care about the longevity of the carabiner. But the suggestion is sneaky and clever and I like it. I'm not sure how much it would change the cost of manufacturing, but I'll look into it.

Panos

RE: Could I make a carabiner's pin/rivet out of copper instead of steel?

Beryllium copper is extremely strong and is available in small diameter bar stock. There is very little Be in the alloy.

Gold alloys are quite soft. Gold-Nickel alloys are quite strong and are available in wire & rod. I believe that South African Krueerands were alloyed with Be to harden them.

RE: Could I make a carabiner's pin/rivet out of copper instead of steel?

(OP)

Quote (weldstan)

Gold alloys are quite soft. Gold-Nickel alloys are quite strong and are available in wire & rod.

So, to my understanding, whenever I want to use a metal that is soft, I always look for alloys of that metal.

Thank you for wisdom, weldstan.

RE: Could I make a carabiner's pin/rivet out of copper instead of steel?

Pretty much the case.

Gold-Nickel alloys most likely will be White Gold.

RE: Could I make a carabiner's pin/rivet out of copper instead of steel?

There are some gold colored alloys that have little or no gold in them.
These are usually Cu-Zn alloys (brasses) some with a little Sn and/or Ni.
Too much Zn and the alloy turns white, too little and it is red. I believe that most 'gold' ones are 12-25% Zn.
Costume jewelery and architectural details are made from these alloys. A little less Zn and bit of Sn or Ni makes them stronger and keeps the color about right.
There is brass flatware sold that looks gold, the old stuff is called Dirilyte and Dirigold, but there is new stuff also.

The other option is gold filled. This is much heavier than plating, but still doesn't use much gold.

= = = = = = = = = = = = = = = = = = = =
Plymouth Tube

RE: Could I make a carabiner's pin/rivet out of copper instead of steel?

(OP)

Quote (EdStainless)

The other option is gold filled. This is much heavier than plating, but still doesn't use much gold.
And this is the kind of alloys I need to look for. I really want to avoid plating to achieve a longer longevity and combine that with a beautiful luxurious color.

Thank you very much EdStainless, weldstan, btrueblood and Compositepro for your replies. I've learned a ton and you made my life much easier.

Panos

RE: Could I make a carabiner's pin/rivet out of copper instead of steel?

I've seen similar carabiners, and they always were inscripted with something along the lines "not for climbing use".
I don't know if that's a necessity in your country, but it sure ruins the design.
Not mentioning this might possibly lead to lawsuits. I hope you have a solution for this that doesn't ruin your design.

RE: Could I make a carabiner's pin/rivet out of copper instead of steel?

I will agree to some extent with btrueblood about BeCu. I worked with the stuff in pure and alloy form 40+ years ago and have lung issues to go along with that experience. Having said that, as long as the Be is tied up in the alloy and not floating free, where either inhalation or skin contact is possible, working with it should not be a problem. When I worked with it, they didn't realize or else admit that there was a contact issue with certain people in addition to the known inhalation issue, the estimate is that 2% of the population may have that extra sensitivity, which can cause slow (30-40 yrs) to develop issues. There is a blood test for it, the Beryllium Lymphocyte Proliferation test. Cause of death is more often than not, lung cancer or heart disease, which seems to accompany it. Some useless trivia to go along with the topic of using Be bearing products.

RE: Could I make a carabiner's pin/rivet out of copper instead of steel?

(OP)

Quote (jwhit)

I will agree to some extent with btrueblood about BeCu. I worked with the stuff in pure and alloy form 40+ years ago and have lung issues to go along with that experience. Having said that, as long as the Be is tied up in the alloy and not floating free, where either inhalation or skin contact is possible, working with it should not be a problem. When I worked with it, they didn't realize or else admit that there was a contact issue with certain people in addition to the known inhalation issue, the estimate is that 2% of the population may have that extra sensitivity, which can cause slow (30-40 yrs) to develop issues. There is a blood test for it, the Beryllium Lymphocyte Proliferation test. Cause of death is more often than not, lung cancer or heart disease, which seems to accompany it. Some useless trivia to go along with the topic of using Be bearing products.

Thank you for your input, jwhit. I'll definitely keep that in mind.

Panos

RE: Could I make a carabiner's pin/rivet out of copper instead of steel?

kingnero makes a very good point. If you're making these in the U.S. and you don't want all of your profits to fund some injury lawyer's vacation home, you might have to ruin your design with that silly warning.

"On the human scale, the laws of Newtonian Physics are non-negotiable"

RE: Could I make a carabiner's pin/rivet out of copper instead of steel?

(OP)

Quote (dwallace1971)

kingnero makes a very good point. If you're making these in the U.S. and you don't want all of your profits to fund some injury lawyer's vacation home, you might have to ruin your design with that silly warning.

dwallace1971 and kingnero, thanks for the heads up, but besides not making the carabiners in the US, I've also seen a carabiner that can be used only as a keychain which is made in the US and is of a US company, and doesn't have the warning on the carabiner, but written only in the packaging and at their website, which doesn't hurt the carabiner's design in any way. I'm not sure if someone could have a case against them.

RE: Could I make a carabiner's pin/rivet out of copper instead of steel?

panosjapan,

The following link shows the variety of colors that can be obtained with different copper-based alloys. Figure III-4. Lots of options from copper to pink/salmon to yellow/gold.

http://www.copper.org/publications/pub_list/pdf/A4...

RE: Could I make a carabiner's pin/rivet out of copper instead of steel?

(OP)

Quote (TVP)

The following link shows the variety of colors that can be obtained with different copper-based alloys. Figure III-4. Lots of options from copper to pink/salmon to yellow/gold.

http://www.copper.org/publications/pub_list/pdf/A4...

Hi TVP. Thank you very much for posting this. It's incredibly helpful. I have one newbie question:

I'm trying to figure out which of those alloys shown in the .pdf are too soft to be used to make a carabiner pin and which aren't. I assume that the two kinds of strength, tensile and yield, are what matter. Is that right? If yes, do both play an important role or one of the two?

Also, what should the number be? I know that brass is a metal hard enough to be used to make a pin and the alloys that include brass in the .pdf have an over 50 tensile strength. Does that mean that the alloy that I'll choose must have an over 50 tensile strength? Or I don't know what the hell I'm saying?

Panos

RE: Could I make a carabiner's pin/rivet out of copper instead of steel?

Yield strength is where you bend something and it takes a set, Tensile (or ultimate tensile) is where it breaks.
If you make this 'biner correctly then the pin will only be loaded in shear, it can't be bent. In that case just look at the ultimate tensile strength.
My gut feel is that you are about right with 50,000psi for a strength.

How strong is the material for the body?
In that part the yield strength will matter since it could be bent.

= = = = = = = = = = = = = = = = = = = =
Plymouth Tube

RE: Could I make a carabiner's pin/rivet out of copper instead of steel?

The carabiners I've seen that were used as keychains were usually anodized aluminum. And they typically used a steel spiral ring to attach the keys, since the hole in the key was normally too small to fit the carabiner body thru.



If aluminum is strong enough for a carabiner key chain body, then any copper alloy should also work. Copper should not need any surface coating. Just the rubbing it experiences in your pocket will put a nice patina on its surface.

RE: Could I make a carabiner's pin/rivet out of copper instead of steel?

@Ed, in shear, he'll need ultimate shear strength. Don't know what it is for Cu alloys, but I'd take around 57% of ultimate in analogy with steel.

RE: Could I make a carabiner's pin/rivet out of copper instead of steel?

(OP)

Quote (EdStainless)

Yield strength is where you bend something and it takes a set, Tensile (or ultimate tensile) is where it breaks.
If you make this 'biner correctly then the pin will only be loaded in shear, it can't be bent. In that case just look at the ultimate tensile strength.
My gut feel is that you are about right with 50,000psi for a strength.

How strong is the material for the body?
In that part the yield strength will matter since it could be bent.
EdStainless, got it about the tensile strength.
The carabiner is made of Zinc alloy. We didn't care much about its strength because it was our intention from the beginning to make it for use as a keychain and not suitable for climbing. I wanted to do it in Stainless Steel, but the cost of the mold for this material was much more expensive compared to a mold for a zinc alloy carabiner. But I'll definitely see what its yield strength is.

Quote (tbuelna)

If aluminum is strong enough for a carabiner key chain body, then any copper alloy should also work. Copper should not need any surface coating. Just the rubbing it experiences in your pocket will put a nice patina on its surface.
Hi tbuelna, yes, but we are talking about the pin of the carabiner. Could it be possible that the pin in the photo you attached is made of stainless steel? About the coating, yes, we don't intend to do any treatment on the pin, that's why I wanted to use copper and take advantage of its unique color.

Quote (kingnero)

@Ed, in shear, he'll need ultimate shear strength. Don't know what it is for Cu alloys, but I'd take around 57% of ultimate in analogy with steel.
Since brass has been deemed as a hard enough material, I'll check its tensile strength and use it as a guide for any future metal choice.

Guys, thank you all for the information. I'll post updates of my project for you to take a look at it if you want.

Best,
Panos

RE: Could I make a carabiner's pin/rivet out of copper instead of steel?

Have you tried a jewelry forum somewhere?

Thomas J. Walz
Carbide Processors, Inc.
www.carbideprocessors.com

Good engineering starts with a Grainger Catalog.

RE: Could I make a carabiner's pin/rivet out of copper instead of steel?

(OP)

Quote (tomwalz)

Have you tried a jewelry forum somewhere?
Never crossed my mind. That's a great suggestion. I'll google for jewelry-making forums. Thanks, tomwalz!

RE: Could I make a carabiner's pin/rivet out of copper instead of steel?

Somewhat crass, but I have a carabiner that was attached to a promotional zipbag, and the carabiner is stamped in relatively large letters

NOT FOR CLIMBING

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RE: Could I make a carabiner's pin/rivet out of copper instead of steel?

(OP)

Quote (IRstuff)

Somewhat crass, but I have a carabiner that was attached to a promotional zipbag, and the carabiner is stamped in relatively large letters
Thanks for your reply IRstuff. I'm sure we can find examples in both cases. I've been noticing many carabiners not suitable for climbing without a warning written on them since the forum brought this matter up, so I think I'll take my chances.

RE: Could I make a carabiner's pin/rivet out of copper instead of steel?

I think if it is small enough you are pretty safe. But then I never thought anyone could win a law suit for spilling hot coffee on themselves.

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RE: Could I make a carabiner's pin/rivet out of copper instead of steel?

The carabiner I was referring to is about same across the long dimension as pictured above, but the print spans the entire diameter of one leg, in the same spot as shown in the promotional carabiner picture above.

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RE: Could I make a carabiner's pin/rivet out of copper instead of steel?

(OP)

Quote (dgallup)

I think if it is small enough you are pretty safe. But then I never thought anyone could win a law suit for spilling hot coffee on themselves.
Idiocracy. mad

Quote (IRstuff)

The carabiner I was referring to is about same across the long dimension as pictured above, but the print spans the entire diameter of one leg, in the same spot as shown in the promotional carabiner picture above.
Thanks, IRstuff. I'll take a deeper look at the whole matter.

RE: Could I make a carabiner's pin/rivet out of copper instead of steel?

There is a Wikipedia article on "carabiner" that discusses the topic. It does state that 'biners intended for climbing are mandated in Europe to have a load rating on them, and similarly for certain uses in the U.S. It would take a pretty naïve climber to use unrated equipment...

RE: Could I make a carabiner's pin/rivet out of copper instead of steel?

(OP)

Quote (btrueblood)

There is a Wikipedia article on "carabiner" that discusses the topic. It does state that 'biners intended for climbing are mandated in Europe to have a load rating on them, and similarly for certain uses in the U.S. It would take a pretty naïve climber to use unrated equipment...

That will make me sleep better tonight. Thank you, btrueblood!

RE: Could I make a carabiner's pin/rivet out of copper instead of steel?

I don't think that it's the people that would even read a load rating are the ones that you need to be worried about. Not to mention kids...

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RE: Could I make a carabiner's pin/rivet out of copper instead of steel?

(OP)

Quote (IRstuff)

I don't think that it's the people that would even read a load rating are the ones that you need to be worried about. Not to mention kids...
IRstuff, thanks for bringing this subject up in the first place. It was something worth looking into it. But I have been seeing for the last couple of days so many carabiner without a warning on them, from big and small companies, that I'm led to believe that it won't be a problem.

RE: Could I make a carabiner's pin/rivet out of copper instead of steel?

"Not to mention kids"

Right, because it's certainly not the parent's job to make sure their kids are not rapelling off the neighbor's roof with un-rated climbing gear.

To be somewhat fair, IRstuff's cautions are probably appropriate for the litigious US market, at least if a supplier intends to be in business for awhile. The reference to idiocracy was an appropriate one, and that movie seems more prescient every day.

RE: Could I make a carabiner's pin/rivet out of copper instead of steel?

(OP)

Quote (btrueblood)

To be somewhat fair, IRstuff's cautions are probably appropriate for the litigious US market, at least if a supplier intends to be in business for awhile. The reference to idiocracy was an appropriate one, and that movie seems more prescient every day.

I agree. The McDonalds example certainly calls for caution. Anyway, moving on..

RE: Could I make a carabiner's pin/rivet out of copper instead of steel?

What not PVD coat a steel pin with titanium nitride? It would be a beautiful gold color and would wear extremely well.

Maui

RE: Could I make a carabiner's pin/rivet out of copper instead of steel?

(OP)

Quote (Maui)


What not PVD coat a steel pin with titanium nitride? It would be a beautiful gold color and would wear extremely well.

Hi Maui and thanks for your reply. I didn't know about this process. I'll definitely look into it. Thanks!

Panos

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