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 broader and squared
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
For the narrow and pointed base, create a small divot in the
The rounded base requires a slightly wider divot in the top
of the ring.
The squared base requires a wide divot with less rounding.
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
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
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
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.
|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
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.