CNC produces popular and commonly used alloys in grain for the jewellery manufacturing industry for the purpose of casting and rolling with special attention given to color, brightness and hardness. These alloy grains are much easier to work with and can be sold in varying quantities.

Also, we are the North American sole representative of Heraeus Ltd. a renowned producer of high quality alloy products for the jewellery manufacturing industry with formulations for all karats ,colors, and tempers. With this partnership we are able to supply sophisticated master alloys for different applications with the highest standards of product quality guaranteed.

Ni-Containing White Alloy

This alloy is termed as a universal alloy for 9-18KW.  Due to its high silicon content, this alloy is only suitable for casting only and not recommended for cold working purpose.  Also, it is more suitable for casting with torches or primitive equipments.  The 22% of nickel in the alloys renders a bit hard for stone setting but its color is regarded as whiter than the average.  This alloy is generally good for 14KW and 18KW.  This alloy can be recommended if the customers asking for better whiteness.  This alloy is excellent for stone casting.  It suffers usually oxidative porosity upon oxidation.

This alloy is a modified version of H-142.  This alloy contains less zinc and silicon which makes this alloy more suitable for the casting with advance casting machines.  The 22% of nickel in the alloys renders a bit hard for stone setting but its color is regarded as whiter than the average.  This alloy is generally good for 14KW and 18KW.  This alloy can be recommended if the customers asking for better whiteness.  This alloy is excellent for stone casting.  It suffers usually oxidative porosity upon oxidation.

This alloy is one of the popular KW alloys in far-east market due to its high fluidity and whiteness.  The alloy is excellent for casting.  This alloy is mainly suitable for 18K.  If the customers occasionally produce 14KW item, this alloy is also suitable.  Though this alloy contains 30% of nickel, its 14-18KW resultant alloys are still EN1811 proved.  Since the alloy contains lesser zinc contents, it seldom has oxidative porosity problem.  However, again due to the low content of zinc, this alloy is easy to have hard spot problem which is a very head-ache problem for our customers upon improper use.  H-145 is regarded as an intermediate product between H-142 and H-106B or H-107. 

This alloy is a modified version of H-145.  The addition of 15% silver lowers the melting temperature of the resultant alloy rendering a better performance in stone in place casting.  Similar to H-145, it is suitable mainly for 18KW casting but it can also be applied to 14KW.  For other properties, it is closely the same as H-145 except it has a bit lower hardness.  However, upon oxidation and improper handling, this alloy may easily have the hardspot which is difficult to be removed.

This alloy is a modified version of H-145.  The slightly increase of the zinc content can significantly reduce the hardspot problem upon improper casting.  This alloy is suitable for stone in place casting especially for 18KW.  Due to the higher zinc content, the porosity problem of this alloy is relatively more abundant than in H-145 if there is oxidation.  The alloy gives very white color for 14KW and even no rhodium plating is required.  However, the hardness of 14KW is a bit at high side.

This alloy gives the whitest color for the 18KW gold.  Besides, this alloy is also suitable for making 21-22KW jewelry.  Due to the high nickel content, the resultant 18KW alloy does not require any rhodium plating.  In general, this alloy gives much better casting performance than the “Precious White” alloy from Cobb.  But due to the nickel content, this alloy is very hard rendering stone-setting is a bit difficult. 

This alloy is originally designed for 14-18KW but in practice, it is mainly used for 18KW due to its high hardness of 200HV.  This alloy is very popular among the local Chinese jewelry manufacturers who require brilliant white color for white gold.  It is also regarded as the first white alloy that the Chinese jewelry manufacturers ever encountered.  Due to its high hardness, it is only used for casting.  If customers requested something with lower hardness, H-107 or H-145B can be recommended though it is comparatively not as white as H-106B.  This alloy usually has oxidative porosity or brittle problem if it is casted improperly.

This alloy is a modified version of H-106B.  This alloy has lower casting temperature and lower hardness than H-106B.  However, it is still only suitable for casting.  Although the color of this alloy is not as white as H-106B but it is already one of the whitest among our alloys.  This alloy can be used for stone-setting as well.  Compared with H-106B, this alloy has less porosity problem and it is easier to be used.  However, if the customers complained its hardness, the H-145B or H-145 has to be suggested.

This alloy used to be the most popular one for making 18KW due to its low hardness.  However, its low Ni content of 17% makes the resultant KW alloy too yellow and easy to have porosity problem.  This alloy is mainly used for casting.  For cold working purpose, it is only conditionally accepted.  The high zinc content also renders oxidative porosity, brittleness and high melt-loss upon improper application. 

Ni-containing white alloy is seldom used for cold working purpose due to its relatively high hardness and fire-cracking problem.  H-148A is in fact an exceptional example of the Ni-containing alloy suitable for 14-18KW cold working purpose such as pressing, hollow jewelry and wiring.  Due to the presence of special grain refiner, this alloy gives very dense and shiny surface after cold working.  Also, the appropriate ratio of the nickel and zinc renders this alloy almost free from fire-cracking problem.  However, this alloy is only suitable for cold working purpose only.  If this alloy is applied for casting, the presence of grain refiner may lead to hard-spot problem. 

Usually the Ni-white alloy for cold working purpose bears insufficient whiteness.  This alloy contains 28% of nickel which renders similar whiteness as normal H-145 and H-147A but the hardness is still in an acceptable range of around 170HV.  Also, due to the low silicon content, the ductility is relatively good and it is suitable for both casting and cold-working purpose.  Again due to the low silicon content, the recycling time of this alloy is limited and it may have more porosity upon numerous recycling. 

Usually, nickel containing alloys have hardness in the range of 150-200HV.  It is very difficult to have the nickel containing alloys with the hardness similar to the green gold.  H-6610A has the hardness of only at 125HV which is even softer than some green gold.  This makes the alloy is extremely good for stone-setting and it is very easy to be used for casting.  With the addition of 5-10% silver, the alloy is excellent for stone casting due to the improved fluidity.  Upon improper use, this alloy may associates with porosity and cracking problem.

This alloy is a universal alloy for casting better than H-142.  The slightly less nickel content of only 20% in this alloy makes the alloy more suitable for stone casting and stone setting.  This alloy contains relatively lower zinc content and therefore the oxidative porosity problem will be less upon recycling.  In order to obtain a better surface in casting, addition of 2-5% of silver in the master alloy is strong suggested.

This alloy is a newly developed Ni-containing alloy for cold working and casting purpose.  This alloy contains only 16% of Ni and it is very soft.  It is suitable for producing white gold from 8K – 18K without any difficulty.  This alloy is extremely gold for 8-14K for the sake of softness and ductility.  For 18KW, although this alloy is a bit off-white, it is generally accepted.

This alloy is similar to H-143C.  However, H-102B has a fluidity and this alloy contains less zinc. It makes the alloy has less oxidative porosity problem.  Also, there will be less melt loss during the casting.  This alloy also gives denser surface and more shiny surface to the cast.

Colored Alloys

This alloy is designed for 8-14KY casting.  It is almost identical to LUX116 from Progold.  Its color is regarded as greenish and it is very suitable for the Turkish market.  A lot of customers prefer this color for making low karat green gold items.  Similar to other low karat alloys, the zinc content of this alloy is quite higher.  It indicates the alloy may be easy to be oxidized especially if it is handled improperly.  H-112 contains more silicon than H-112B.  It indicates that the alloy H-112 has much better recycling time than H-112B but the new alloy may be easier to have cracking problem due to the surplus silicon in the alloys.

H-126 is suitable for 8-14KY casting.  The color of this alloy is regarded as pinkish yellow which is one of the popular colors for EU market.  Comparing with other alloys for low karat gold, this alloy contains relatively less zinc indicating it has less oxidative porosity problem.  To cope with different production method, this alloy has some derivatives such as H-126A which contains less silicon rendering it suitable for casting with better facilities.  The silicon free version, H-126R is developed for cold working purpose.

H-136A is suitable for 8-14KY casting.  It bears a greenish yellow color which is very popular for the US market.  Similar to other normal low karat alloys, its relatively high zinc content renders a higher chance of getting oxidative porosity upon improper use To cope with the different production method, derivatives such as H-136B and H-136D are developed.  H-136D has the same color but it is developed for the cold-working purpose.

H-139 is suitable for 8-14KY casting.  This alloy gives a slightly more rich greenish yellow color than H-136A.  It is also very popular for the US market.  However, due to its slightly higher silver content  than H-136A, it is more expensive than H-136A.  This alloy is almost identical to M5123I from Advance.

H-210 is suitable for 8-14KY casting.  It has a pale yellow color which is one of the popular colors for the EU market.  Together with H-126 and H-136A, these three items can be regarded as the most frequently requested alloys.  This alloy is very easily to handle.  Compare with H-136A, it has less porosity problem.  The cold-working version of H-210 will be developed upon requested by customers.

H-160C is suitable for 8-14KY casting.  Its deep yellow color is especially popular for the Indian market.  It is equivalent to the well-known alloy, UA1 in India.  Some Indian customers also used it for 18KY although it is not recommended here.  The alloy contains less than 10% of zinc indicating the ductility of this alloy is very good.  Besides, the oxidative porosity is less due to the presence of zinc.  Similar to other yellow alloy, it also has derivatives with different amount of silicon.  H-160D has the same color as H-160C but it is designed for cold-working purpose.

H-188B is suitable for 14-18KY casting and some customers even extend its application to 10KY.  The color of this alloy is regarded as Hamilton yellow, which is very popular in US market.  Similar to the alloys mentioned above, this alloy also has different derivatives containing different amount of silicon.  The silicon free version, H-188D is specially designed for cold working purpose.  However, due to the presence of high percentage of zinc, the alloy may have oxidative porosity upon improper use.  Also, the ductility of the resultant alloy is worse and it may have cracking problem during casting.  Also, due to its high silver content, the selling price of this alloy is relatively higher.

H-188B is suitable for 14-18KY casting and some customers even extend its application to 10KY.  The color of this alloy is regarded as Hamilton yellow, which is very popular in US market.  Similar to the alloys mentioned above, this alloy also has different derivatives containing different amount of silicon.  The silicon free version, H-188D is specially designed for cold working purpose.  However, due to the presence of high percentage of zinc, the alloy may have oxidative porosity upon improper use.  Also, the ductility of the resultant alloy is worse and it may have cracking problem during casting.  Also, due to its high silver content, the selling price of this alloy is relatively higher.

This alloy is an improved version and our intensive trials showed that this alloy is less sensitive towards the intermetallic s formation.  This indicates that the alloy is not easy to become brittle.  This alloy is suitable for 10-18KR casting and it gives the typical red color (5N).  This alloy is also good for continuous casting.  But of course, the ingot from continuous casting must be cooled effectively and rapidly after casting. 

This alloy gives the deepest red color for 18KR.  It is also suitable for 10-14KR casting.  However, due to its high copper content, the alloy is easy to crack if the casting is not handled properly.  If the customers always have cracking problem with this alloy in 18KR casting, they are suggested to quench faster or they have to consider an alloy with lighter color.

This alloy contains 15% of silver. This makes the alloy is easy to cast and easy to do machining.  The color of this alloy is sometimes referred as “Russian Red”.  The alloy is not very sensitive towards intermetallics formation resulting its ductile nature.  This alloy can be used for cold-working purpose without too much problems.  However, due to the higher silver content, its color is bit paler.

This alloy is also for 10-18KR casting.  Due to its relatively high silver content, it gives only a pink color.  But at the same time, this alloy is the most user-friendly.  It can be used as normal yellow gold except still a bit difficulty in stone casting.  If the customers do not care too much about the color or they want some pink gold which is easy to handle, H-152 should be their choice.

H-177A is suitable for 18KY casting.  Its yellow color is regarded as standard yellow or equivalent to 3N color.  It gives the most popular color among all the yellow gold no matter for EU or US market.  According to different production, we also developed a series of derivatives such as H-177B and H-177C, which contains less amount of silicon.  Since this alloy has higher percentage of silver indicating it is more sensitive towards the presence of silicon which is not soluble in silver.  Therefore, the customers should be advised to consider changing to the one with less silicon once they experience cracking problem.  Due to the low content of zinc, the alloy seldom has oxidative porosity problems.  For cold-working purpose, the customers can use H-177R. 

H-179B is suitable for both 18KY casting and cold working purpose.  The color of this alloy is regarded as greenish yellow or equivalent to 2N color.  Sometimes this color is also termed as Italian yellow.  It is popular for EU market and Japanese market.  Since the alloy contains high content of silver, silicon is not added for deoxidizing purpose except one of its derivatives, H-179F.  But usually, this alloy seldom has cracking problem unless improper handling.  H-179B used to be very popular among the market.  However, due to its silver content and the change of the fashion trend, it is no longer as popular as in the past.  Anyway, if the customers asked the alloy with less greenish tint,

H-177A can be suggested.  In contrast, if they asked for something with even more greenish color, H-186 can be suggested.

This alloy is suitable for 10-18KY casting and cold-working purpose.  Its color is regarded as green yellow or champagne yellow.  It is very green comparing with other typical yellow color.  However, due to its high silver content, the operating temperature is relatively higher rendering high risks of getting gas porosity and rough surface problem.  In contrast, this alloy seldom has oxidative porosity problem due to its low zinc content.

H-172C is suitable for 14-18KY casting and cold working purpose.  The color of this alloy is regarded as reddish yellow, which is very popular among the Asian market.  The local customers in China prefer H-172C more than H-177A since H-177A is too greenish for them.  In general, this alloy has no obvious application problem but cracking problem is occasionally found when we applied this alloy for stone casting.  The cracking is attributed to the relatively high zinc content for 18KY.  In fact, no matter what the alloy is, 18KY alloy should not contain too much zinc metal.

This alloy is suitable for 18-22KY casting and cold working purpose.  The color of the resultant 22KY alloy is regarded as deep yellow or rich yellow.  This color is very popular for the Middle East market.  The hardness of this alloy is only of around 90HV.  It is a normal hardness for 22KY though the customers usually ask the alloy with higher hardness.  Due to the high content of gold, the customers usually have no application for 22KY items at all no matter they use only raw silver and copper.  Since the market of this alloy is limited, if the customers ask alloy with different color, we do have different recipes but we may not consider to produce unless they request in larger quantity.

Sterling Silver

H-330 is another brass-based master alloy for making sterling silver and its resultant sterling silver alloys are called O-DAG.  Similar to H-PAT, it has substantial anti-tarnishing ability and oxidation resistance.  Due to the presence of silicon, it gives even better deoxidizing ability to the alloy.  Unlike H-PAT, it can also be used for torch melting or casting with relatively primitive facilities.  This reveals that this alloy is suitable for most Chinese customers who have usually only primitive equipment.  The resultant alloy is suitable for both casting and cold-working purpose.  Upon oxidation, the alloy usually has oxidation porosity problem and some red-stain problem if it is heavily oxidized.  In general, the number of recycling of this alloy is better than H-PAT.  In some cases, if the customers have cracking problem with this alloy, you should consider whether there is too much silicon for their application since excessive silicon in the silver alloy can cause severe cracking problem.  If this is the case, you should use the alloy with less silicon or even silicon free.  Moreover, the presence of silicon may cause also hard spot problem upon oxidation.

H-550 is a copper based master alloy for making sterling silver and the resultant alloy is called O-SAG.  Despite its high copper content, it contains also a high percentageof silicon, which gives a very good anti-oxidation ability to the resultant sterling silver.  Besides, the presence of silicon can harden the alloy.  The measured hardness of this alloy can be up to 70HV, which is significantly higher than those of O-DAG and O-AAG.  The silicon can also enhance the anti-tarnishing ability of the sterling silver.  Unless severe oxidation, the alloy seldom has oxidative porosity problem but may associate with some red-stains.  But due to the high content of silicon, upon oxidation, the alloy may have sometimes hard spot problem which caused difficulty in polishing.  Since silicon is not soluble in silver, too much silicon in the alloy can cause cracking problem resulting from the segregation of the silicon from the alloy especially upon slow cooling.  If the customers do not satisfy with the red-stain problem in this alloy, O-DAG should be suggested.

H-449 is another master alloy with high zinc content for making sterling silver and its resultant sterling silver is called O-ZAG.  Similar to other sterling silvers, it bears also substantial anti-tarnishing ability.  Owing to its high content of zinc, it seldom has red-stain problem and it can even be regarded as red-stain free alloy.  Also, this alloy is suitable for torch melting.  Though the presence of zinc gives the above advantages, it at the same time gives some drawbacks too.  O-ZAG has relatively lower hardness of only 53 HV but it only causes problem when we cast filigree items.  Upon oxidation, the alloy may have oxidative porosity problem or even cracking problem due to the accumulation of zinc oxides.  If the customers found difficulties in handling this alloy, they should consider to change the alloy to H-430 and also they have to consider up-grading the casting facilities and/or review the casting procedure that they currently use.

H-336 & O-BAG

H-430 is a newly developed master alloy with high zinc content for making sterling silver.  Similar to other sterling silver from Heraeus, it bears excellent anti-tarnishing ability.  Owing to its high content of zinc, it rarely has red-stain problem and it can even be regarded as red-stain free alloy.  Also, this alloy is suitable for torch melting.  Though the presence of zinc gives the above advantages, it at the same time gives some drawbacks too.  Upon oxidation, the alloy may have oxidative porosity problem or even cracking problem due to the accumulation of zinc oxides.  If the customers found difficulties in handling this alloy especially because to the hardness, they should consider to change the alloy to H-632 or H-550.