Processes For Cutting Jewellery Designs

7 Apr 10

ManufactureLink receives enquiries on a regular basis from jewellery designers needing precious metals cut who are not sure what process works best. Common enquiries are along the lines of needing jewellery cutting, sterling silver cutting, platinum cutting, or cutting of delicate patterns in stainless steel.

Often the jewellery designer has begun cutting their designs out by hand but business has increased to the point where they need to find a faster method. But cutting of delicate patterns in metals like sterling silver can be difficult and you need to choose a suitable process to achieve the results you need. So what are the best methods to cut jewellery? The following is a general outline of the methods available along with links to find suplpiers who have each process.

Laser Cutting

Laser cutting is often passed over as either too 'rough' or not able to cut precious metals. But Laser cutting can be used as long as you select the correct laser process. The one you want for sterling silver cutting, platinum cutting, stainless steel cutting, titanium cutting etc is the Nd:YAG process or what we term on our network as 'fine laser cutting'.

Companies that specialise in this type of cutting are typically engaged in cutting of delicate parts in thin metals for the medical or electronics industries. The Nd:YAG laser cutting process can cut incredibly delicate parts with very precise accuracy in a wide variety of materials. Almost no heat is imparted to the parent metal and there is no distortion.

While most materials can be cut, softer metals can leave a small amount of dross on the edges of the cut. But the laser cutter is typically adept at using mechanical techniques such as tumbling or vibratory deburring, or chemical techniques such as pickling to remove the dross.

Click here to locate a laser cutter with the Nd:YAG laser cutting process.

Waterjet Cutting

Waterjet cutting is often the process jewellery designers ask about. Most have enough knowledge of the process to know it can cut a very wide range of materials very cleanly. Waterjet cutting is also excellent for cutting soft materials.

Waterjet cutting can cut just about any precious metal a jewellery designer uses but there are some drawbacks. Firstly, the accuracy is not as good as for other processes. As a general rule of thumb, a tolerance of 0.1mm is the best you can achieve with this process.

The second drawback is most waterjet cutters are not doing delicate work and may not have clamping systems or work holding systems available for this type of work. So the types of cuts they may be able to perform may be limited to larger pieces.

Click here to locate suppliers who perform waterjet cutting.

Photo Chemical Machining (PCM)

Photo Chemical Machining works by printing the design onto the surface of the sheet metal. The are that is printed is the part you want to keep. The printing is called 'photo resist' and when the sheet is placed in the chemical etching bath, the non-printed areas are chemically etched away leaving the desired components.

This process is well suited to producing extremely delicate parts as there are no cutting forces or heat. Many parts can be cut from a single sheet simultaneously.

The drawbacks are the materials that can be photo chemically machined are limited. The parts must be cut from flat sheets and the accuracy is not as good as Nd:YAG laser cutting and the cutting speed is much slower. The design also needs to incorporate small tabs to hold the completed parts in position until etching is complete (a good idea for all processes anyway).

Click here to find manufacturers who do photo chemical machining.

Wirecutting

Often thought of as for cutting of tool steels only, wirecutting is an excellent process that can be used to cut almost any metal. Cutting is achieved by eroding the metal away using a current passed through a wire. The wire is precisely controlled using computer numeric control.

Wirecutting is a good process for delicate parts as there are no cutting forces and practically no heat imparted to the workpiece. Another key advantage of wirecutting is that it is common and toolmakers with wire cutting capability are easy to find.

The drawbacks are that cutting can be slow and the wire needs at least a hole to start in if the design is not open.

Click here to find toolmakers with wire cutting capability.

Die Cutting and Stamping

If the volumes you want to produce are high enough, or the designs are simple, you may want to consider die cutting, stamping or punching your parts out.

For thin metals, a die cutting knife can made to cut the parts from a sheet. This is the same process used to cut seals and gaskets from thin metals, rubber or fiber materials as well as the method used to cut cardboard shapes. To die-cut your jewellery parts you need to get a die cutting knife made and have the parts cut by someone with a press.

Stamping can mean either hand stamping or stamping in a turret punching machine. The automated stamping process is used to produce higher volumes of parts. Stamping tools can be expensive but part production is fast and low-cost. In addition to punching out basic shapes (blanking), stamping or metal forming can be used to put surface features on the parts, bend them, fold them, and form functional features all in one tool (progressive stamping tool).

ManufactureLink is often asked about making hand stamps by jewellery designers. The stamps are used to either cut out small designs or stamping patterns or logos onto the metal surface by striking with a hammer.

Stamping tools whether they be for automated production of hand stamps are produced by toolmakers.

Click here to find toolmakers who make stamping tools.

Click here to find companies that do die cutting.

High Speed Machining

Sometimes with delicate jewellery designs, you need extreme precision, fast cutting speed and absolutely no dross or burrs. You may need to consider high speed machining as an option if the other processes won't suit.

The theory with this type of machining is that by using very high spindle speeds with small cuts at high feed rates, very little cutting forces and heat are generated but you benefit from the accuracy machining can provide. By high spindle speeds we mean 20,000rpm or greater and not all machinists who claim to perform high speed machining have the required spindle speeds available.

Setup and clamping of the parts can be difficult with this process (and expensive) but the results with machining soft precious metals such as platinum can be very good.

Click here to locate high speed machinists.

Part Design For Production

What ever process is chosen, it pays to think a little about your component design when moving to higher volume production. Often intricate jewellery designs have very delicate features. When designing you parts for production, consider supporting delicate features with small 'tabs'. These tabs hold the design together or hold the completed part in the sheet stock during cutting. This helps support the part and assists material handling and part delivery.

You receive the parts still held in the sheet by the tabs. Parts are removed from the sheet and supporting tabs removed by using sharp cutters or a sharp knife.

Talk to your chosen manufacturer about designing your parts better for production as it can save you a lot of money in the long run.

More Help

If you are still not sure which process will best suit your parts to be cut, ManufactureLink provides personal assistance free-of-charge to help you and help you find the right manufacturer. Or simply start talking to one of the many suppliers in our network that you will find on our manufacturing directory.

Click here to contact ManufactureLink and request assistance.

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