Tag Archives: steel jewelry manufacturer

Stainless steel jewelry production, wire-cut EDM

Are you curios to know how we cut steel pendents in stainless steel jewelry production?

Is there any alternative ? what are the advantages using wire cut in Stainless steel jewelry production?

How it effect the price and delivery time?

Read about one of the most used fabrication methods in stainless steel jewelry production.

The wire-cut EDM is electrical discharge machine that uses CNC controller and continuous-traveling vertical wire under tension as one of the electrode to produce the desired shape.

The wire in wire-cut EDM is about as thick as a small diameter needle which allows creating a very delicate parts or shapes. In the stainless steel jewelry industry this fabrication method mostly used to cut flat parts out of steel sheets i.e. dog tag pendants.

Wire cut in stainless steel jewelry production considered to be a slow fabrication methods.  As the industry advanced and if the thickens of the steel jewelry product we produce allowed. We prefer to use laser or plasma cutting. Which speed the process.

Another disadvantage of wire cut is the finish of the part edges. in most cases it will require longer and costly polish process.

Wire-cut EDM  Machining According to Wikipedia.org:

“In wire electrical discharge machining (WEDM), also known as wire-cut EDM and wire cutting, a thin single-strand metal wire, usually brass, is fed through the workpiece. The wire, which is constantly fed from a spool, is held between upper and lower guides. The guides move in the X-Y plane, and sometimes the upper guide can also move independently giving rise to transitioning shapes (circle on the bottom square at the top). This gives the Wire-cut EDM  the ability to be programmed to cut very intricate and delicate shapes. The wire-cut uses water as its dielectric with the water’s resistivity and other electrical properties carefully controlled by filters and de-ionizer units…”  [View Wikipedia Entry]

Wire-cut EDM Machining Process

Wire-cut EDM  machining also known as Electrical Discharge Machining is an electro thermal production process in which a thin single-strand metal wire in conjunction with de-ionized water (used to conduct electricity) allows the wire to cut through metal by the use of heat from electrical sparks.

Due to the inherent properties of the process, Wire-cut EDM  can easily cut complex parts and precision components out of hard conductive materials.

How Wire-cut EDM Works with stainless steel jewelry

Wire-cut EDM  machining also known as spark EDM  works by creating an electrical discharge between the wire or electrode, & the work piece. As the spark jumps across the gap, material is removed from both the work piece & the electrode.

wire-cut-steel-jewelry-pendant

steel pendant in wire cut machine

 

To stop the sparking process from shorting out, a non conductive fluid or dielectric is also applied. The waste material is removed by the dielectric, and the process continues.

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Hulpf team

 

Toxic substances in stainless steel jewelry

Toxic substances in stainless steel jewelry , international standards.

  1. Definition
  2. Limits
  3. Test methods
  4. Test report example

I’ve seen a lot of arguments back and forth on the issue of toxic substances in stainless steel and fashion jewelry,  and one thing that really jumps out at me is how much confusion and misunderstanding there is regarding what the standards related to jewelry really mean. This is an attempt to clear up some of the confusion including simple instruction and up to date jewelry lab report examples.

High metal contamination in low-cost jewelry is a widespread problem. While the U.S. and Canadian legislation put emphasis on lead exposure prevention, other toxic elements like cadmium in jewelry are not regulated except in paint and coatings. After much discussion and consultation the European Commission has completed amendments to Annex XVII of Regulation1907/2006 (REACH), and published an Updated as on February 2016.

What regulations do we follow?

We at Hulpf jewelry follow the European Regulation and the REACH Annex XVII in specific as the EU legislation  regarding Toxic substances in stainless steel jewelry is more comprehensive and updated.

What substances related to steel jewelry we test for?

  1. Lead (Pb) content. Read more
  2. Cadmium (Cd) content. Read more
  3. Nickel (Ni) release. Read more…
  4. AZO dyes. Read more…

Where do we test  for Toxic substances in stainless steel jewelry ?

There are numerous independent internationally recognized labs and organization. We use SGS to test for toxic substances in stainless steel jewelry that we manufacture.

What the regulations mean to me as a customer?

Lead and its compounds in jewelry.

Section 63, Annex XVII of REACH will restrict the concentration of lead to 0.05% by weight. This will apply to any individual part of stainless steel jewelry articles, imitation jewelry, fashion jewelry, and hair accessories, including bracelets, necklaces and rings; piercing jewelry, wristwatches and wrist-wear; brooches and cufflinks.

63. 7439-92-1 231-100-4 Lead and its compounds

Shall not be placed on the market or used in any individual part of jewelry articles if the concentration of lead (expressed as metal) in such a part is equal to or greater than 0.05 % by weight.

(i) “jewellery articles” shall include jewellery and imitation jewellery articles and hair accessories, including:
(a) Bracelets, necklaces and rings;
(b) Piercingjewellery;
(c) Wrist watches and wrist-wear;
(d) Brooches and cufflinks;
(ii) “Any individual part” shall include the materials from which the jewellery is made, as well as the individual components of the jewellery articles.

Cadmium and its compounds in jewelry

Section 23, Annex XVII of REACH will restrict the concentration of Cadmium to 0.01% by weight.
This will apply to any individual components and assembled stainless steel and fashion jewelry articles.

23. 7440-43-9 231-152-8 Cadmium and its compounds.
Shall not be used or placed on the market if the concentration is equal to or greater than 0, 01 % by weight of the metal in:
(i) Metal beads and other metal components for jewellery making;
(ii) Metal parts of jewellery and imitation jewellery articles and hair accessories, including: bracelets, necklaces and rings, piercing jewellery, wrist-watches and wrist-wear, brooches and cufflinks.

Nickel release in jewelry.

Nickel and its compounds may pierce the skin and cause allergic contact dermatitis. The EU Directive 2004/96/EC was issued on 27 September 2004 to restrict the use of nickel in consumer products that may have contact with skin such as buttons, fashion jewelry, sunglasses and belt buckles. After REACH took into force, the directive was replaced by the Regulation (EC) No. 1907/2006 (REACH). Nickel release was then added to the REACH Annex XVII – REACH Restriction List.

The Requirements of REACH Restriction are for the release of the nickel in a given time and not the absolute content. There are 2 main jewelry categories.

  1. Articles that intend to pierce the human body for example ear studs and should release less than 0.2 µg/cm 2/week.
  2. Articles that intend to come into direct contact with the human skin should release less than 0.5 µg/cm 2/week.

7. 7440-02-0 231-111-4 Nickel and its compound
Shall not be used:
(a) in any post assemblies which are inserted into pierced ears and other pierced parts of the human body unless the rate of nickel release from such post assemblies is less than 0,2 µg/cm 2/week (migration limit);
(b) In articles intended to come into direct and prolonged contact with the
skin such as: earrings, necklaces, bracelets and chains, anklets, finger rings, wrist-watch cases, watch straps and lighteners, rivet buttons, lighteners, rivets, zippers and metal marks, when these are used in garments, If the rate of nickel release from the parts of these articles coming into direct and prolonged contact with the skin is greater than 0,5 µg/cm2 / week.

AZO dyes in jewelry.

AZO dyes are the name of the group of synthetic dyestuffs based on nitrogen that are often used in textile industry. Some AZO dye stuffs may separate under certain conditions to produce carcinogenic and allergenic aromatic amines.
Since Annex XVII of REACH came into force in 2009, the AZO Directive 2002/61/EC has been replaced by REACH regulation. AZO dyes are put on REACH Restriction List.  Leather and textile components in jewelry articles made of colored leather or other synthetic materials should contain less than 30 mg/kg.

43. 405-665-4 Azocolourants&Azo Dyes
2. Azodyes, which are contained in Appendix 9, ‘List of azodyes’, shall not be placed on the market or used for colouring textile and leather articles as a substance or constituent of mixtures in concentrations higher than 0,1 % by mass.
1. Azodyes which, by reductive cleavage of one or more azo groups, may release one or more of the aromatic amines listed in Appendix 8, in detectable concentrations, i.e. above 30 mg/kg (0,003 % by weight) in the articles or in the dyed parts thereof, according to the testing methods listed in Appendix 10, shall not be used, in textile and leather articles which may come into direct and prolonged contact with the human skin or oral cavity, such as: clothing, bedding, towels, hairpieces, wigs, hats, nappies and other sanitary items, sleeping bags, footwear, gloves, wristwatch straps, handbags, purses/ wallets, briefcases, chair covers, purses worn round the neck, textile or leather toys and toys which include textile or leather garments, Yarn and fabrics intended for use by the final consumer

How jewelry test reports look like?

This jewelry custom project involved different types of materials and components that related to all the above substances we mentioned in this post. For one of the bracelets we use synthetic colored polyester and we test for 22 different AZO dyes. In this bracelet AZO test report you can notice that the limits allowed is 30mg/kg and the result shows that none of the substances were deducted.

The silver color bracelet made of Brass and was tested for Cadmium content. In this bracelet Cadmium test report the results show content of 26mg/kg which is below the limit defined by REACH Annex 0.1% or 100 mg/kg.  For lead content test we choose to test several beads from the same jewelry project. The test report shows content of 22mg/kg much below the limit of 0.5% allowed by the EU regulation for stainless steel or fashion jewelry. For the nickel release test we choose different beads from the same project. This Nickel release report shows that the beads release less than the 0.5 µg/cm 2/week the max allowed rate for jewelry that come into direct contact with the human skin.

I hope that in this post I was able to clear some of the confusion surrounding REACH regulations  and make  toxic substances in production of stainless steel and fashion jewelry easier to understand.

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stainless steel jewelry manufacturer ad Hulpf

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How to clean stainless steel jewelry info

Stainless steel jewelry is made of a steel alloy that contains minimum of 10.5% chromium and less than 1.2% Carbon content.
The advantage is that it doesn’t corrode or rust.
Although it is also very durable, steel jewelry may get scratched and stained.
Bellow some simple rules to keep your stainless steel jewelry in good condition.

Things You will Need

1. Bowl

2. Dish-washing or window-cleaning liquid

3. Fabric

4. Towel

5. Toothpaste(optional)

6. Jewelry polish or polishing cloth(optional)

7. Bags or pouches(for maintain)

Stainless Steel Jewelry Cleaning

Stainless steel jewelry is pretty easy to clean. Simply follow below steps:

1. Pour some warm water in a little bowl, and add some mild dish-washing or window-cleaning liquid.

2. Dip a soft, lint-free fabric in the soapy water, and then gently wipe the stainless steel jewelry with the damp fabric til the piece is clean. Once cleaning it, rub the jewelry along its polish lines.

3. Wipe the remaining soap off your jewelry using a wet fabric dipped in clean water.

4. Dry the jewelry well with a clean towel, and then leave your pieces to air dry.

After your stainless steel jewelry is cleaned, you will be able to use a jewelry polish or a polishing cloth to shine it.

Some people use toothpaste to clean the especially dirty spots of their stainless steel jewelries. Keep in mind, however, that toothpaste is abrasive. If you decide to use it for cleaning, make sure it is a non-whitening brand that does not contain silica, and use a soft cloth to rub the paste onto your pieces. Don’t forget to rinse the jewelry thoroughly after you are done.

An alternative to these cleaning methods is to purchase a stainless steel cleaner from the store and follow the instructions on the package.

Stainless Steel Jewelry Maintaining and Storing

Although stainless steel jewelry doesn’t tarnish or corrode and doesn’t need special care, it will scratch. That’s why you should wear and store your pieces in a way to minimizes any contact with other items that can damage your stainless steel jewelry. If your jewelry does get scratched, you can always have it professionally polished by a jeweler.

Store your stainless steel pieces individually from jewelry made of other metals. It is best if you retain your stainless steel jewelry in individual bags or pouches.

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Hulpf teamStainless steel jewelry-earring by Hulpf

Steel jewelry casting How to?

Investment casting is one of the oldest known metal-forming techniques. In general, the jewelry cast part obtained by allowing molten steel to solidify in a mold then clean and removed to polish and further assembly if necessary.

Steel jewelry castings allow the production of irregular shapes that usually can not be done or are too costly and time-consuming to produce using CNC machine, one of the main fabrication methods for stainless steel jewelry.

Steel jewelry casting is a process of making jewelry pieces that involves the pouring of liquid steel into a mold. It is usually referred to as lost-wax casting because the casting mold is created using a wax model that is melted away to leave a hollow chamber in the middle of the mold. The technique has been used for thousands of years, and is still widely used today to make reproductions of stainless steel jewelry.

The steps in steel jewelry casting

1. Choose a model for casting. A model could be a piece of jewelry that you want to make a mold out of. You can use any piece of your own jewelry that you are interested in reproducing.

2. Build a rubber mold using your model.

  • (1) Prepare an un-vulcanized rubber molding compound. You can purchase it at your local arts and crafts supply store.
  • (2) Press your model into a appropriately sized mass of the rubber molding compound. Make sure to surround the model entirely to ensure an entire mold for casting jewelry. The compound are going to be soft and pliable till you cure it, therefore we don’t need to  worry about damaging your model.
  • (3) Subject the rubber mold to heat according to manufacturer’s directions so as to vulcanize, or cure, the rubber. The finished product can similar in consistency to a rubber bouncy ball.
  • (4) Use a surgeon’s knife to dissect the model out of the mold. Slice down the middle of the rubber mold, length-wise on the model, making a mold that opens like a book. Watch out at this stage not to harm your model with the surgical knife.
  • (5) Remove the model, being very careful to stay the mold intact, as any imperfections in your mold can lead to a imperfect wax casting.
  • (6) Cut a shallow channel into every face of the mold, resulting in the hollow chamber left by the model. The two channels ought to meet once the mold is closed along, making a tunnel in which you will insert the syringe.

3. Inject the mold with melted wax. Use any kind of crater’s wax that you purchase from an arts and crafts supply store. There are many different types of wax, and they each have different melting points, therefore experiment with a variety to find one you like the most.

  • (1) Melt the wax in a double-boiler, referring to the package directions for the proper melting temperature.
  • (2) Use a medication dosing syringe to inject the melted wax into the closed mold, inserting the syringe through the divot channel you created within the jewelry casting mold.

4. Allow the wax to cool completely. Cooling times vary, base on the particular wax you purchase. Follow package guidelines for cooling times.

5. Take away the wax model from the rubber mold. This may currently be your model for the lost-wax jewelry casting process.

6. Make a stand for the model. Cut a thin stick of hardened wax, simply large enough to support the wax model, and fix it to the model with melted wax.

7. Secure the wax model stand to the bottom of a casting flask, using more melted wax. The model ought to be propped up within the flask. It’s ready for the jewelry casting process.

8. Combine the dry ingredients of the gypsum plaster-based investment mold material with water, as per manufacturer’s directions.

9. Pour the investment mold molten steel mixture into the flask, compassing the model completely. 10. Enable the investment mold to set.

11. Place the entire flask in a kiln set to close to 1100 degrees F (600 degrees C). This may harden the mold and melt the wax away, leaving a hollow chamber within the center of the cast jewelry mold.

12. Remove the mold from the flask. 13. Pour the casting.

  • (1) Place your metal of choice in a pouring crucible, then melt it inside a foundry. The melting temperature and time are going to be determined by the sort of metal you are using.
  • (2) Pour stainless steel liquid metal from the pouring crucible into the mold through the tunnel left by the melted wax support stick.

14. Enable the metal to cool.

15. Tap the mold gently with a hammer to break away the mold and reveal the jewelry casting.

16. Buff out any irregularities on the jewelry piece using a metal buffing wheel.

Please note that the above method will enable you to produce steel jewelry using casting process but you probably encounter quality issue such s porosity, shrinkage etc..

For high quality steel jewelry casting  the process must be carefully monitor and should be done using Vacuum casting machine specially designed for stainless steel jewelry.

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Hulpf team