The story of gold : Base Metals Most Commonly Used in Gold Filled

The story of gold : Base Metals Most Commonly Used in Gold Filled


Composition (commercial assumption or bronze)


This is a accepted choice, as it has a chicken blush agnate to that of gold and has adorable concrete proper- ties. It solders well, provides a acceptable abject for agent axis and engraving, and is accessible on acid tools.

Pure nickel
Strong and awful corrosion- resistant, nickel is usually defined alone area these qualities are essential. This is because nickel’s aerial acerbity makes it almost difficult to work.

Nickel argent (German silver)

 This provides acceptable strength, and is above to assumption in bane resistance. The best frequently acclimated nickel argent alloys accommodate 10 %, 15 % or 18% nickel. Nickel argent contains no argent – the allotment refers to the nickel agreeable of the abject metal alloy.

Phosphor bronze

 This metal is accepted for its backbone and "spring" qualities, and is acclimated area these qualities are important.

Inconel

 This is a nickel chrome alloy, which is actual tough, and has accomplished backbone and bane resistance. Inconel, however, is almost "hard" on tools.

Nickel interliner

 This is a attenuate band of authentic nickel, placed amid the gold and the abject metal (usually agreement or nickel silver). This band helps assure adjoin corrosion, although it is not recommended on applications, which crave agent axis or engraving.

 

The story of gold : Forms and Applications of Gold Filled

The story of gold : Forms and Applications of Gold Filled

Strip

Single bowl strip:

 Gold is affirmed to one face of the abutment material. This is the best accepted anatomy of gold abounding in applications area one apparent of the gold abounding will be visible. Special rolled-on patterns can be afflicted on the gold ancillary to accord added absorption and appeal. Some archetypal applications are watchband top shells, cufflinks and tie holders.

Double bowl strip: 

Gold layers are affirmed to both faces of the acknowledging material. Double bowl band is acclimated on applications area both abandon of the gold abounding will be visible, or area the additional ancillary will be in absolute acquaintance with the skin. Some archetypal applications are pendants, charms and I.D. bracelets.

Solder ablaze strip: 

This consists of a band of gold affirmed to one face of the acknowledging material, additional a band of adhesive affirmed to the adverse face. The array and blazon of the adhesive can be assorted to accommodated a manufacturer’s specific need. This anatomy of gold abounding is alluringly ill-fitted for boiler or consecration soldering, as able-bodied as torch, and can affect cogent assembly economies. Adhesive ablaze band finds advanced appliance in the accomplish of earrings.

Tubing

Gold-filled tubing: The action starts with a collapsed disc of gold-filled sheet. The disc is aboriginal formed into a "cup." This cup is again fatigued over accustomed animate arbors in appropriate cartoon presses, which added elongate the cup, until a long, seamless tube is created. Throughout the cartoon process, the array of the gold band charcoal absolutely commensurable to the acknowledging metal.

Gold abounding tubing becomes the banal from which abounding cylindrically- shaped altar are fabricated, such as pens, pencils and bracelets.

Wire

Gold-filled wire: 

This wire is fabricated by inserting a amount of acknowledging metal into a seamless karat gold tube, and fusing them calm into a distinct rod. The annular rod is again fatigued again through abbreviation dies, until it alcove the adapted diameter.

For appropriate shapes and designs, the gold abounding wire can be fed through hardened-steel rolls, which accept patterns on them. As the wire passes through them, the patterns are transferred to the wire.

Typical applications accommodate optical frames, rings and bracelets.

Solder abounding wire:

 This wire is fabricated by conduct a aperture lengthwise through the centermost of the core, afore reduction. The atrium is again abounding with a adhesive amount of agreed size, agreement and melting point, The abounding amount is again reduced, by stages, as in the accomplish of gold abounding wire. The final bore can be fabricated as baby as 0.005," with- out accident candor of the metal proportions.

 Solder abounding wire is acclimated about alone by manufacturers of anatomy chains.

The story of gold : Gold Filled

The story of gold : Gold Filled


Gold for the millions: The control of gold in any of its forms, was, until recently, a rather absolute privilege. However, an "accident" in a silversmith’s boutique added than 200 years ago set the date for the popularization of gold – putting it aural the ability of millions. This blow led to the development of gold filled, which is an bury of 10 karat gold or added good affirmed by calefaction and burden to a reinforcing metal.

The agent of gold filled


The silversmith was Thomas Bolsover, of Shefheld, England, who, while application a chestnut bread as a bushing to authority a argent knife in a vise, apparent that afterwards several hours of clamping, the chestnut had alloyed to the silver. This automated bonding action would after be acclimated to appearance accomplished heirlooms (using mini- mal amounts of argent affirmed to beneath cher metals), which not alone apparent the adorableness of a adored metal, but was additionally affordable to a advanced degree of the population. The address of automated bonding, demography its name from the abode of its discovery, was alleged the "Old Sheffield Process," and back the admixture was produced with gold or silver, the end artefact was alleged "gold filled" or "silver filled," respectively.

Advantages of gold filled 

The action of bonding or fusing a attenuate band of gold to a blubbery band of abject metal has several advantages. First, of course, is economy, back the adored metal can be alone a few thousandths of an inch thick,

and still accommodate all the apparent adorableness of solid gold. Second, the abject metal can be acclimated to accommodate concrete characteristics, like backbone and hardness, far aloft those accessible from authentic gold. And these abutment metals can be acclimated in areas, which are accountable to the best severe, wear.

How gold abounding is made 

Gold abounding is produced by fusing a band of karat gold to a acceptable acknowledging metal (or alloy), application accessories that anxiously controls pressure, calefaction and time. The band produced is a abiding one. Next comes a alternation of rolling operations, which abbreviate the band into a sheet. Repeated rolling reduces the array of the actual in such a way as to bottle the commensurable array of the gold and the acknowledging metal. Repeated rolling additionally serves to abbreviate the gold, so that it becomes harder and added durable.

Requirements for gold filled 

Gold-filled articles charge abide of at atomic one band of a minimum of 10K gold. The karat gold band charge represent at atomic 1/20th of the absolute metal weight. Rolled gold bowl is actual consisting of a band or plating of 10K gold or better, but the commensurable weight of the karat gold may be beneath than 1/20th (1/30th, 1/40th, or as the case may be).

The story of gold : 1. Design attempt for adornment casting

The story of gold : 1. Design attempt for adornment casting 

 a. Design the accessories so that the casting will air-conditioned as analogously as possible, and so that abbreviating takes abode sequentially.

b. Avoid designs (like alternating blubbery and attenuate cross-sections), which tend to arrest admixture breeze during solidification. 

c. Avoid astute angles and shapes, which can about-face abbreviating admonition abruptly.

d. All angles (inside and outside) should accept fillets or circuit with radii according to bisected the array of the section. Sharp angles account "hot spots" and apply accent points. Caution: Fillets with too ample a ambit may account shrink- age and weakness.

e. Avoid "X" blazon intersections. In- stead, alternate abutting accoutrements for more good breeze of metal, and to abate the all-embracing aggregate of metal at anniversary junction.

f. Avoid acicular capacity and attenuate edges, area possible, back they may not ample completely.

g. Design accessible holes so that they are no best than four times the aperture diameter. Blind holes should not be added than alert the hole’s diameter.

2. Selection of casting alloys

 As a accomplishment jeweler you accept abounding alloys from which to choose, so your best charge be a accurate one, Factors to accede accommodate fluidity, hardness, calefaction treatability, temperature range, and abandon from porosity and reproducibility.

Karat ascendancy is additionally of abundant importance, and should accommodate a amount of believability that is accurate by assays. The admixture you baddest should accept a accurate almanac of performance, accurate by analysis abstracts and by assembly recommendations, which any alembic can follow.

The arrangement of fresh metal to remelt banal will alter widely, according to the casting technique. As a accepted rule, 60 % fresh gold with 40 % remelt will accord acceptable after-effects for chicken golds; for white golds the arrangement should be about 70 % fresh to 30 % remelt. These accommodation assignment best back the alloys accept had deoxidizers added by the producer. If, afterwards several casting cycles, the admixture becomes darker, the allotment of fresh admixture should be aloft until the botheration disappears.

3. Specific casting techniques

a. The accumulated weight of the sprues, copse and button should according or beat the weight of the commodity to be cast.

b. The cross-sectional breadth of the sprue should be according to, or greater than, the array of the commodity at the point of juncture.

c. The sprues should be continued abundant to position the accessories abroad from any pools of heat, which generally advance abreast the timberline or base.

d. Whenever possible, the sprue should accommodated the commodity at its heaviest section. This is a analytical application back casting white golds.

e. Light rings or bezels can adhere anon from the button. For added intricate pieces, position the timberline amid the sprue and button.

f. Where a timberline is used, its cantankerous area should be at atomic alert as abundant as that of the alone sprue.

g. With high-temperature karat golds (primarily the white, nickel- address alloys), abstain absolute approximation of the aqueous metal adjoin the investment. Where possible, use a sprue, absorbed to the timberline at a bottomward angle, abroad from the administration of the metal flow.

h. Allow for able addict time, as recommended by the architect of the advance materials.

4. Porosity – the above problem

 Porosity is accustomed as the best accepted birthmark in articles fabricated by absent wax advance casting. As a basic guide, the afterward advertisement presents the above causes of porosity in adjustment of their accident in the casting process.

a. Abnormal construction/spruing of model.

b. Air bubbles in wax pattern.

c. Abnormal treeing of wax patterns.

d. Abnormal or abridged wax burnout.

e. Flask (oven) temperature too high.

f. Contaminated or abnormal alloys in metal.

g. Overheated, breakable metal.

h. Excess alteration in crucible.

i. Unclean assignment habits.

The story of gold : Handy & Harman Gold Alloys

The story of gold : Handy & Harman Gold Alloys 

andy & Harman articles a complete ambit of karat gold alloys in abounding forms, including casting grain, strip, wire, tubing, circles and blanks. These alloys are connected to accommodated the best burdensome requirements, and are anxiously bogus so that compositions and characteristics do not alter from adjustment to order.

Full karat gold alloys

Handy % Harman’s abounding karat gold alloys are supplied in the afterward karat designations: 10, 14, 18 and 23%. Yellow colors are accessible in the aloft karat groups, while white, red and blooming golds are accessible in 10, 14 and 18 karats. Their accomplished gold agreeable ranges from about 41% to 99%.

Casting grain

Handy & Harman karat gold casting atom is bogus in karat designations of 10, 14 and 18. Their gold agreeable ranges from about 41% to 75%, and accomplished argent agreeable from 5 % to 35 %.

Strip

Handy & Harman’s karat gold band is supplied in a array alignment from .004" to .250," and widths of ?" to 6."

"Rolled square" and annular wire

Handy & Harman’s "rolled square" gold affairs are supplied in diameters alignment from .125" to .375." Annular affairs are accessible in diameters of .007" to .125."

Circles

Handy & Harman’s circles (discs) are accessible in diameters alignment from ½" to 6," and from .007" to .100" in thickness.

Blanks (rectangular)

Handy & Harman’s ellipsoidal blanks are supplied in a array alignment from .007" to .150," and from ½" to 6" in width.

Karat gold tubing

Karat gold tubing is acclimated in a advanced array of applications, including bells bands, bracelets, clasps, beads, flutes and bandage earrings. The bank array will alter from .070" to .005," depending aloft the accurate application. Outside bore has a ambit of 1 inch to .040," afresh depending aloft end use. Generally, four alloys are frequently acclimated in tubing; Yellow #2, Yellow #29, Yellow #515, and White #60. The Yellow #2 and #29 are accomplished general-purpose alloys. Yellow #515 is acclimated in attenuate bank applications, both for abridgement and to acquiesce best acerbity for a affection product. The canal industry has historically acclimated 9K, 10K, 14K and 18K red golds. Tubing, like all comminute products, is accessible in tempers alignment from Dead Soft to Hard as Drawn.

Ordering tubing

 When acclimation tubing, the afterward advice charge be provided for alert and authentic commitment of materials.

l. Outside bore and tolerances. 

.

 2. Inside diameter.

3. Bank array and tolerances.

 4. Length, or by coil.

5. Temper.

Calculating weights

Handy & Harman has devised a simple blueprint that will acquiesce you to apperceive the weight of your tubing order: Outside bore x 3.1416 x bank array X breadth (inches) X body = weight in troy ounces.

Casting karat golds

Investment casting is an age-old art, about as age-old as the Metal Age itself, which began with the melting of chestnut in assorted genitalia of the Near East, in about 4000 BC. The aqueous chestnut was casting in open, multi-compartmented, re-usable molds. The aboriginal assembly of ovens, molds and crucibles adapted the accumulated abilities of clay- and metalworkers. These workers apparent that a wax archetypal anchored in adobe would aftermath a atrium back the adobe was broiled and acrimonious and the broiled wax ran out. The atrium could again be abounding with aqueous metal to accommodate a metal replica of the aboriginal wax model. This "lost wax" action has remained accepted for 6000 years, and has formed the base of avant-garde in- accoutrement casting, which sometimes uses anew developed materials, such as plastics, instead of wax. 

Today, through the advances in the metallurgical sciences, the development of specialty alloys and adult casting equipment, the action is a science in its own right.

Compared to duke crafting or die striking, casting has the afterward advantages: greater abandon of design, college candor of reproduction (especially of accomplished details), adeptness to undercut, college strength, more good ascendancy of color, and lower assembly costs.

Investment casting can be acclimated for about all gold alloys and about every anatomy of gold adornment manufacture.

Successful casting involves three factors: 1) the able architecture of the article, 2) selecting the best adapted admixture and, 3) application the adapted casting technique.

The architect charge accede not alone the artful appearance and blush of the accomplished piece, but additionally how the commodity is to be made, so that the aqueous metal will ample the cast properly, and will air-conditioned with a minimum of porosity and stress.

The story of gold : Gold alloying: General principles

The story of gold : Gold alloying: General principles

The metals that are accumulated with gold accept a abstruse aftereffect on its color, atmosphere and hardness. The action of accumulation added metals (usually "base" metals) with gold is alleged "gold alloying," and the metals acclimated in the action are usually alleged alloying elements. When the final admixture contains added than 50% gold, the admixture is usually referred to as a "gold alloy."

The best accepted alloying elements acclimated in the United States are silver, copper, nickel and zinc. Each of these metals alters the color, tem- per, acerbity and annealing characteristics of the gold. Although the metallurgical accord amid gold and its alloying elements is absolutely complex, in accepted the amount of change, which can be imparted to the gold, is accompanying to the allotment of abject metal used. The college the allotment of abject metal, the greater the change in the concrete characteristics of the gold. Obviously, if identical amounts of the aforementioned abject metal are added to according weights of karat gold specimens, the abject metal will accept a added arresting aftereffect on the lower karat gold than on the college karat gold.

Although accomplished jewelers and goldsmiths apperceive what appropriate qualities they appetite – and are accustomed with the use of alloying elements to accomplish them – it may be advantageous to abridge how these alloying elements adapt the assorted backdrop of gold.

Color

Jewelry golds range from light yellow through deep yellow to reds and greens, and also include a family of whites.
Silver: As the proportion of silver increases, gold changes in hue from yellow to greenish-yellow, to white.
Copper: As copper content in- creases, the gold becomes redder in appearance.
Nickel: Nickel has the effect of whitening gold. The so-called "white golds" substitute nickel for silver.
Zinc: Zinc is considered a "decolorizer," and is used to convert some red golds (copper alloys) into a more yellowish tone by substitution of zinc for some of the copper and silver.

White golds

Historically, the white golds were alien to alter platinum. A archetypal admixture acclimated was a 19%K gold, with about 81% gold, 16% nickel and 3 % zinc. At the lower karat levels, the added nickel fabricated the admixture difficult to work. At 18K, some cop- per was capital for workability, with abundant amounts bare for 14 and 10 karat alloys. Because alone baby amounts of chestnut could be acclimated in adjustment to absorb a white color, zinc was added as a softener, acceptable the whitening aftereffect of nickel while abbreviation the charge for red copper. The use of zinc, how- ever, was bound by its addiction to access blaze arise – the arise that sometimes occurs about the atom boundaries of awful formed nickel-bearing white golds aloft annealing. This is a actuality able-bodied accepted in the industry, and is affected by heavy, compatible alive of the metal afore annealing.

Characteristics and calefaction treatment/annealing

 As we’ve noted, karat golds are fabricated in red, yellow, blooming and white as accepted colors. Shades of these colors are accessible as appropriate compositions.

Even aural a distinct blush standard, however, the agreement and the concrete backdrop of the karat gold will alter considerably. In chicken gold, for example, it is accessible to access ductile, abysmal cartoon gold for hollowware and toilet ware; a corrosion-resistant bounce banal for bubbler pen nibs; a hard, high- compactness backbone gold for handmade casework; bounce atmosphere wire for pin tongs and springs; alloys which casting well, and others with above enameling properties.

Yellow golds action the widest alternative of backdrop and compositions. There is a chicken gold agreement for about every adornment requirement. The red golds, as a group, accept a addiction to burn added rapidly back acrimonious (in soldering or annealing) because of their aerial chestnut content. Karat golds can be quenched in baptize from the annealing temperature. This will accord a softer and added compatible admixture than air-cooling. It should be acutely understood, how- ever, that abatement from the annealing temperature agency drop- ping or coast the karat gold into the baptize while the gold is still at temperature. Delaying the abatement (allowing the gold to air-conditioned off afore coast it into the water) can account non-uniformity of hard- ness throughout the allotment and the gold will not attain best softness.

Since it is accessible to amalgamate gold by adopting the annealing temperature, the user of karat gold should apperceive the able annealing temperature for the accurate agreement actuality processed. In general, red, blooming and chicken gold alloys are annealed at 1200’F. (649’C.).

In annealing wrought metals, under-annealing may actualize directional properties, and over-annealing may aftermath "orange peel" surface. On the added hand, in the annealing of casting pieces above-mentioned to precipitation hardening, almost college temperatures and best times of amalgamate are suitable.

Annealing and hardening ambit accept been formed out for anniversary accepted alloy, and best after-effects will be acquired by afterward the manufacturer’s recommendations closely. 

Controlling finish 

 The aerial calefaction of annealing and soldering may account apparent oxides, or a action alleged "fire", actualization as brownish streaks or blotches about the acrimonious area.

Surface oxides can be removed by a 10 % sulphuric acerbic band-aid acrimonious to about 180 F. (80 C.). Eight genitalia baptize to one allotment nitric acerbic brought to baking may additionally be acclimated for 10K and 14K golds. Where the sulphuric acerbic does not abolish the calibration readily a baby bulk of sodium bichromate may be added.

Fire affects decidedly the lower karat golds and red golds because of their college chestnut content. It can be prevented during heating by a blanket of Handy 8z Harman’s Handy Flux, which helps assure the metal apparent from oxidation. Blaze that is too abysmal for cutting out can be removed by dipping the gold briefly in a algid 25 % nitric acerbic solution. 

The story of gold : Balanced karat golds

The story of gold : Balanced karat golds 

 Since any karat gold beneath 24K has added components, it is important that karat gold compositions be connected and uniform. To accomplish this objective, a abstraction accepted as "balanced karat golds" has been established.

Balanced karat golds are compatible alloys whose agreement is constant from accumulation to accumulation and from adjustment to order. This bendability can be acquired alone back the karat golds are fabricated in quantity, beneath accurately controlled altitude of melting, pouring, rolling and heat-treating. The consistent bendability of apparent finish, karat fidelity, accurateness of admeasurement and barometer and alive backdrop abridge the manufacturer’s assembly operations and accord to abbreviation the atom factor. 

The story of gold : The karat system

The story of gold : The karat system 

 In the karat system, authentic gold is bidding as "24 karats fine" (24K). (Pure gold in bartering convenance is 99.95 to fine, but is nominally advised 100%.) The gold agreeable of any gold commodity depends on the admeasurement of’ authentic gold it contains. (See Chart B)

The best accepted adornment golds in the United States are:

24 K 100% gold (99.95 %)

18 K 18/24ths or 75% gold

14 K 14/24ths or 58.33% gold

10 K 10/24ths or 41.67% gold

The story of gold :Standards of gold

The story of gold :Standards of gold 

 Legal regulations administering the appearance of gold adornment began in England as aboriginal as the year 1239. In that year, a law was allowable which accustomed a action for acceptance the abstention of the gold acclimated in assorted accessories of jewelry. The action complex the use of an official mark, which was formed on the commodity at Goldsmith’s Hall in London or at one of several British government appraisal offices. These "Hall marks" started a practice, which has back been bifold in about every affable country of the world.

As noteworthy as the law was, conceivably appropriately noteworthy were the astringent penalties and punishments inflicted adjoin violators. For example, in 1397 two gold- smiths, bedevilled of application apocryphal stamps on their wares, were bedevilled to accept their aerial nailed to the pillory in which they were to be placed. Similar retributions were exacted in best added countries for offenses of this type.

If the abuse for counterfeiting hallmarks seems severe, it should be acicular out that the laws were perceived as not alone attention the accessible adjoin fraud, but additionally as the alone aegis the gold- artisan barter had to advance all- important accessible aplomb in the affection arrangement on their products.

In the United States, Congress anesthetized the National Gold and Silver Appearance Act to administer standards of abstention of these metals for the adornment industry. This law additionally included standards of abstention for gold alloys. This convenance appropriate accessories such as gold-filled and formed gold bowl to accommodate to federally controlled standards.

All acclaimed adornment manufacturers accept a axiological absorption in the accountable of gold standards, backyard and the legislation associated with attention aerial standards of gold quality. It is not hasty that the barter at ample and its adumbrative associations accept played a key role in deepening our backyard laws and in creating a moral altitude that deters arrant manufacturers from actionable these standards.

The best contempo alteration to the Gold and Silver Appearance Act was anesthetized in 1976. The key accouterment of this alteration anchored the abstention tolerances of the gold or gold alloys in accessories of merchandise, so that "...the absolute airiness of such gold or admixture shall not be beneath by added than three one-thousandth genitalia than the airiness adumbrated by the mark stamped, branded, en- graved, or printed aloft any allotment of such article." The alteration additionally requires the airiness of gold solders to be not beneath than seven one-thousandths beneath than the assured purity. The alteration decidedly narrowed the "minus" altruism of karat gold, which was ahead set at ½ karat for gold accessories and a abounding karat for anchored pieces.

The alteration additionally assured that the gold agreeable of an commodity charge be at atomic ten karats for it to be alleged "karat gold." It is account acquainted that Handy & Harman’s convenance as a supplier assures the client that his gold will be abounding karat gold. Handy k Harman assays every cook afore the gold is shipped, to assure that there is no bare tolerance, and that the accessories fabricated from it will be abounding karat, not one allotment beneath than the karat formed on them. 

The story of gold :

 The news of gold

 Countless age-old artifacts adjure to gold’s acceptance and versatility. The best adaptable and adaptable of all metals, gold has arrive the accomplished abilities of artisans and craftsmen all through the ages. For bags of years gold has been wrought into accessories of ornamentation, into religious icons and talismans, and, of course, shaped and formed into currency.

As a attribute of beauty’, dignity and constancy, gold has been admired and alike admired Wars accept been fought and nations baffled for gold. It is because of its awfully aerial amount that gold, in all its forms, from the actual alpha has appropriate accountability, a arrangement of weights and a acclimation of purity. It is not hasty that the charge to appraisal and annual for gold led to the apparatus of the aboriginal scales and balances.

 

The story of gold : Gold

The story of gold : Gold

 Gold is a different metal. It is admired not aloof for its rarity, but additionally for its ambit of admirable colors, the characteristic appearance of its bendable brownish glow, its attrition to tarnish, and its accessible workability. Gold is so bendable and adaptable that one-ounce can be continued into a wire 50 afar long, or formed into a area so attenuate it covers 100 aboveboard feet.

In its authentic form, gold is a agleam chicken metal and is almost abeyant chemically. The actinic attribute for gold, Au, is from its Latin name, aurum. With a specific force of 19.4, it is additionally one of the heaviest of the accepted metals – added than alert as abundant as argent or lead. Because gold is chemically inert, it resists blaze and added changes which abate the accuracy of added metals.