Working with Peg Heads

October 1998

For Your Staff:Selling Quality

Working with Peg Heads

Knowing the proper way to connect peg heads to mountings demonstrates another aspect of quality in your shop

by Mark B. Mann
Director of Professional Certification
Jewelers of America

Over the years, I've had calls from several jewelers and consumers relating stories of diamonds lost after falling out of rings. But I was astonished the first time a caller said the diamond and the head were lost.

The consumer was wearing her two-month-old ring with a 0.50-ct. diamond set into a peg-style head when the diamond and the head fell off unnoticed and were lost. Afterward, close inspection showed the peg head was not soldered into the mounting properly and broke off after being bumped a few times during normal wear.

The illustrations here and on the next page show some typical peg heads and how they are assembled correctly and incorrectly.


Different Peg Head Styles

Typically, a peg head is die-struck and mechanically formed. When soldered correctly onto a ring, it offers a quality mounting in which to set diamonds. It's essential, however, for the peg head to have full contact with the shank &150; contact from the base of the peg to the base of the head.

 

Base very narrow & pointed

 

Base rounded

 

Base broader and squared


Assembled Correctly

To ensure a safe and secure assembly, each of the following examples requires a slightly different preparation and soldering technique. The proper preparation &150 shown at right &150 ensures a secure mounting for your customers' stones.

For the narrow and pointed base, create a small divot in the ring.

The rounded base requires a slightly wider divot in the top of the ring.

The squared base requires a wide divot with less rounding.


Assembled Incorrectly

In each of these examples, the peg is the only portion of the head that comes in contact with the ring mounting and, when soldered, provides a less-than-secure assembly. As these examples encounter normal wear, the heads will bend and eventually break off.


Replacing Ring Assembly

In some cases, the manufactured ring assembly must be replaced because it is insufficient for soldering a peg head.

 

The bar is very thin and the ring into which the peg head is to be inserted is too thin and too large in diameter for the peg.

 

The proper solution is to remove the bar and circle provided by the manufacturer and hand-make and install a new assembly.


Beware of Partially Soldered Heads

 

Solder covers only the bottom of the peg.

 

Solder is incomplete, covering only a portion of the peg and not the base.


Closeup of Properly Prepared Mounting & Peg Head Assembly

Arrow # 1
The solder must flow from the bottom of the peg.

Arrow # 2
Solder must flow up to and secure the bottom of the base of the peg head. Use a 10x loupe to be sure this has been done. Look for a bond between the base of the head and the ring.

 

 

 


JA Quality Assurance Guide
Working With Peg Heads

Properly Executed Head
and Shank Assembly

1. There is complete contact at the union of the peg head and mounting.

2. The solder joint is complete – with no pits – and covers the base of the peg to the top of the base of the head.

3. The assembly of the head is symmetrical and even with the design of the shank.

4. The finish and polish of the prongs is free of any evidence of die striking and other tool marks.

5. The stone is set properly (Professional Jeweler, February 1998, pp. 183-184 for the features of a quality prong setting). Please turn the page for examples of potential problems with head and shank assemblies.



Potential Problems

Head Above Surface of the Shank
Only the peg (and not the base) of the head is in contact with the shank. The head eventually will break off, and the head and stone could be lost. This is due to errors in workmanship.

Die-Striking Lines on Inside of Prongs
Die-striking lines and other tool marks are not removed. The surface of all sides of each prong should be smooth and even.

 Head & Shank Not Aligned

The prongs should be positioned properly with the shank and in alignment from several viewing angles.

 Too Much of Shank Removed

Too much shank has been removed and contact is inadequate, resulting in a weak assembly with no shank support. Also, too much of the head is covered, resulting in a poor appearance.


Base of Peg Is All That's Soldered

The head and shank have been properly prepared, but the head is soldered only at the base of the peg and not on the base of the head. You must use a 10x loupe or gemological microscope to confirm that a proper union has been made.

 

 


Illustrations by Lainie Mann

©1998 Jewelers of America
This information is required for the second level of the JA® Certified Bench Jeweler program



Copyright © 1998 by Bond Communications.


 

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