Tension Setting - How do they get the diamond in?

[kenny]

How they get the diamond in is kind of a brainteaser for me.
It is like pondering the proverbial ship in a bottle.

Idea #1
They make the ring with a gap for the stone.
They pull the ring open and drop in the stone.
Then let go.
Somehow the metal just springs back to grip the stone.

Idea #2
The metal is heated to become liquid.
It is poured into a mold that already contains the diamond.

Idea #3
The ring is made in two parts, each with a grove cut out for the diamond.
Then the other ends are somehow connected together, perhaps by welding.

Idea #4
The ring is made with a gap wider than the diamond, but with extra thickness near the diamond.
Then that thick metal is somehow pushed towards the stone to grip it.

I hear there are 3 companies who are respected for doing it right, Neissin, Steven Kretchmer, Gelin Abaci - yet a zillion jewelers will be happy to do it for you.
I hear the proper process is top secret.
Do you suppose that only these top three know the secret process and the rest do it a less reliable way?

 

[strmrdr]

spread em and slip it in.

 

[strmrdr]

lol that sounded dirty but your #1 idea is correct.
They make the opening slightly smaller than the diamond cut some shallow groves for the diamond.
Then pry it open and pop the diamond in.
It springs back in and holds the diamond.
The problem is getting an alloy that will retain enough tension to hold it in over the long term.
Gold and plat are not well suited for it TI is much better.

 

[kenny]

Why does the metal spring back?

So if I were to take a finished ring and spread em it would spring back again?
Or does the ring have to be heated or cooled to increase the springieness?
Don't worry I won't try this at home.
I just have an inquiring mind.

You make it sound pretty simple.
If so, why do these three companies charge so much more than the corner jeweler?
Just sucessful marketing?
So, any jeweler can do it just as well?

 

[pyramid]

I don''t know but I always thought it was a secret in the alloy mix. Like a good baker has a secret recipe.

 

[strmrdr]

Getting the right alloy is the biggest issue.
Heat treatment of the alloy could also be a factor.
But its inner related with finding the right alloy.

Tension settings work because the ring wants to close the gap and the diamond is holding it open.
Therefore the no diamond state of the ring has to be with a smaller opening.

 

[kenny]

strmrdr wrote: "Gold and plat are not well suited for it TI is much better."

So why is titanium not offered by the big 3 tension setters?

Let me guess.
The mind of the public.
The public is not of a mind to go with what is mechanically superior.
Rather they insist on the tradition and the romance of gold and platinum.

Guess two: There is more profit in gold and platinum than in titanium.

I hear there is a company in Canada that does tension settings called Absolute Titanium.
Is there a well respected one in America?

 

[strmrdr]

http://www.boonerings.com/

Yep tradition mostly.
TI is seen as a less romantic material.

 

[MissAva]

Very cool....

 

[kenny]

So gold and platinum don''t hold tension as long or as well as titanium.
Any advice for owners of tension settings in gold and plat?

Is tension in metal a property that can "wear out" like magnetism?
Are there things that would relieve some of the tension that we should avoid doing?

Might the following things affect the tension:
Putting an outward expanding force on ring, such as when making a tight fist that makes fingers expand.

Exposing the ring to heat or cold, take the ring off when showering or washing hands in hot water or swimming in cold water.
Never leaving in a hot or cold car.

Avoid impact to the metal.

Or will these things have no effect?

 

[mepearl53]

Gold and platinum are perfect for tensions settings. I''ve had experience with them for 18 years and only two diamonds have come out both caused by a serious blow to the hand. Most jewelers don''t consider the other metals "fine jewelry" and that''s why you don''t see them much other than craft or alternative shops. The advantage to tension setting is there are no prongs and you can''t catch them on your clothing, husband, or children. They show off a diamond better than any other setting but the style is more industrial but I love the look. More metal actually touches the diamond than a traditional prong ring. 60% metal touch is the minimum of the designer we use. A traditional 4 prong ring has about 1600 lbs of pressure and although it varies the designer we use has 12,000 lbs of pressure. This is per square inch. The spring to the metal is produced by a specially developed alloy blended to reduce the possibilities of stress fracturing. The metal colors are vivid and the surface is very hard. The rings are "aged" in a furnace to reduce brittleness.

The debate is, "who is the best" of the three major players in this design category? Kretchmer, Galin, or the German fellow (never could spell his name)

 

[mepearl53]

Date: 7/22/2005 11:17:53 AM
Author: kenny
So gold and platinum don''t hold tension as long or as well as titanium.
Any advice for owners of tension settings in gold and plat?

Is tension in metal a property that can ''wear out'' like magnetism?
Are there things that would relieve some of the tension that we should avoid doing?

Might the following things affect the tension:
Putting an outward expanding force on ring, such as when making a tight fist that makes fingers expand.

Exposing the ring to heat or cold, take the ring off when showering or washing hands in hot water or swimming in cold water.
Never leaving in a hot or cold car.

Avoid impact to the metal.

Or will these things have no effect?

I don''t believe titanium has been around long enough to form that opinion. The tension does not wear out. Pressure from your finger, heat, cold, swimming, washing, or leaving it in your car will have no impact on the metal. Of course a major blow to the ring could have a effect but this would be true with any metal.

 

[JCJD]

Curious... so is setting a diamond in a tension setting as risky (potentially chipping the stone) as channel setting, less risky, or more risky? Obviously, experience will remove much of this risk as well as the stone''s shape (round vs princess for example), but in general?

Great topic!

 

[kenny]

Good question JCJD.

Speaking of risk during setting, do all 3 major tension setters insure for damage during setting?
I know Gelin Abaci does.
Bill, you carry Steven Kretchmer, does he?

And what percentage of prong-setters insure their work?
50%?
20%?
80%?

I know all 3 tension setters must approve the stone themselves prior to accepting the job.
Integrity of stone is critical to withstanding the pressure.
I think they also examine internal stresses with a polariscope.

I think this is where the rubber meets the road, the setter's willingness to insure their labor.
Actually, this may not be a fair comparison since the tension setters will only accept the safer stones.

 

[mepearl53]

Date: 7/22/2005 5:26:22 PM
Author: JCJD
Curious... so is setting a diamond in a tension setting as risky (potentially chipping the stone) as channel setting, less risky, or more risky? Obviously, experience will remove much of this risk as well as the stone''s shape (round vs princess for example), but in general?

Great topic!

No, but it depends on the diamond. Most tention rings are spread with a seat cut into them to match the girdle of the diamond being used. When the diamond is set the mounting is slowly let go and it softly clasps the diamond. It is recommended to use VS2 clarity or above but some SI stones with inclusions located in the center of the diamond can be used. Cleavages don''t work well and this is where most problems occur. A ideal cut diamond also works best. I''m not a expert on channel setting but our bench people have chipped far more diamond with this method than our tensions but diamonds set in channel are usually smaller.

Someone mentioned in another thread that these rings cannot be sizes and this is true. A very slight alteration can be made maybe 1/4 size. So I tell people this. I''ve been married for 32 years. I married my wife for many reasons one of which is her beauty. She is as beautiful today to me as she was then. We stay active and in shape. It''s good for the body and good for our love affair. We are the same size as we were when we married. SO, no need to alter anything All the health chatter is more pounds need to come off! If your getting a ring like this stay in shape. I can assure you it will go a long way in your health and feelings about yourself.

 

[mepearl53]

Date: 7/22/2005 5:41:05 PM
Author: kenny
Good question JCJD.

Speaking of risk during setting, do all 3 major tension setters insure for damage during setting?
I know Gelin Abaci does.
Bill, you carry Steven Kretchmer, does he?

And what percentage of prong-setters insure their work?
50%?
20%?
80%?

I know all 3 tension setters must approve the stone themselves prior to accepting the job.
Integrity of stone is critical to withstanding the pressure.
I think they also examine internal stresses with a polariscope.

I think this is where the rubber meets the road, the setter''s willingness to insure their labor.
Actually, this may not be a fair comparison since the tension setters will only accept the safer stones.

This was a discussion on another thread awhile back and my opinion was that the jeweler has 100% of the risk if they accept the job. We do and that is all I can talk to. We do represent Steven Kretchmer, my friend, and the man when it comes to metallurgy IMHO. We accept 100 % of the risk if we accept the job so prong work is no different. The other people who accept outside work will have to chime in hear for I cannot speak for them. The tension guys have no choice but to examine the diamonds and accept those diamonds that will work best with their work. The polariscope will determine the ability of a stone to be set safely.