The Ultimate Guide to Precision Laser Cutting Jewelry: Gold, Silver, and Brass

A jeweler loads a 0.5 mm 18‑karat gold sheet onto a generic CO₂ laser and attempts to cut a filigree pendant. The laser either reflects off the surface and fails to cut, or it finally couples, burns a wide, blackened kerf, and melts the delicate scrollwork into a blob. The same shop tries a multi‑mode fiber laser. The cut is ragged, the edge is discolored, and the scrap rate on 500 pendants exceeds 40%. The gold dust trapped in the machine’s extraction filters is worth more than the labor saved.

The direct answer to why precious metals are difficult to laser cut is their extreme room‑temperature reflectivity at 1,070 nm—95% for gold, 97% for silver, 93% for polished brass—combined with high thermal conductivity. For gold and silver, the power density of a multi‑mode fiber laser is insufficient to initiate a stable keyhole within microseconds. The energy is reflected back into the optics or conducted away into the sheet, causing widespread heating, melting, and warping before a cut begins. The corrective approach is a single‑mode fiber laser with a pulse duration of 20–50 ns and a focused spot under 40 µm. At this intensity, the keyhole ignites almost instantly, absorption jumps to near‑100%, and the heat‑affected zone shrinks to less than 40 µm. The cut is clean, the edge is bright, and the scrap rate falls to under 1%.

This article provides the parameter windows, assist gas strategies, and workholding requirements for precision laser cutting of gold, silver, and brass in thicknesses from 0.3 mm to 1.5 mm. All parameters are validated on a YIHAI LASER XC2030 precision fiber laser cutter, a 200 × 300 mm machine that delivers 0.03 mm positioning accuracy and a single‑mode beam quality suitable for micron‑level kerf control.

The Reflectivity Threshold and Power Density Requirement

Gold, silver, and brass are among the most reflective metals at the fiber laser wavelength. The table below lists their room‑temperature absorptivity, thermal conductivity, and the minimum power density required to form a keyhole within 10 µs, which is the threshold for a clean, narrow kerf.

Metal	Absorptivity at 1,070 nm (cold)	Thermal Conductivity (W/m·K)	Keyhole Initiation Power Density (W/cm²)
18K Gold (Au‑Cu‑Ag alloy)	5–8%	120–150	8 × 10⁷
Fine Silver (99.9% Ag)	3–5%	430	1.2 × 10⁸
Sterling Silver (92.5% Ag)	4–6%	360	1.0 × 10⁸
Cartridge Brass (70% Cu, 30% Zn)	7–10%	120	5 × 10⁷

A single‑mode fiber laser with a 40 µm spot and 1.5 kW average power delivers a power density of 1.2 × 10⁸ W/cm², exceeding the keyhole threshold for all three metals. A multi‑mode laser with a 120 µm spot at the same power delivers only 1.3 × 10⁷ W/cm²—insufficient for gold and silver. This is the fundamental physical reason why a single‑mode laser is mandatory for precious metal cutting, not merely preferable.

Once the keyhole forms, multiple internal reflections trap the beam, and the effective absorption rises to over 90%. The energy is deposited in the kerf walls, not in the surrounding sheet. The challenge then shifts to controlling the pulse duration so that the heat‑affected zone is minimized and the kerf width is consistent.

Optimized Cutting Parameters for Gold, Silver, and Brass

The table below provides validated cutting parameters for a YIHAI LASER XC2030 equipped with a 1.5 kW single‑mode MOPA fiber laser (Maxphotonics MFSC‑1500) and a 40 µm focused spot. All cuts use nitrogen assist gas at 99.995% purity and a coaxial nozzle with a standoff of 0.6 mm. The material thickness range covers the common sheet gauges used in jewelry fabrication.

Material	Thickness (mm)	Average Power (W)	Pulse Duration (ns)	Pulse Frequency (kHz)	Cutting Speed (mm/s)	Kerf Width (µm)	Edge Quality
18K Yellow Gold	0.3	400	30	70	350	28	Bright, no discoloration
18K Yellow Gold	0.5	550	35	60	220	32	Bright, no dross
18K Yellow Gold	0.8	700	40	50	140	38	Bright, slight bottom burr removable by hand
Fine Silver (99.9%)	0.3	450	25	80	300	25	White, matte edge
Fine Silver	0.5	600	30	65	180	30	White, no oxidation
Sterling Silver	0.5	550	30	65	190	30	Bright, no tarnish
Sterling Silver	0.8	750	35	55	120	35	Slight edge softening; acceptable for post‑polish
Cartridge Brass	0.5	500	40	60	250	32	Bright, minimal zinc evaporation
Cartridge Brass	0.8	650	45	50	160	36	Bright, slight edge rounding
Cartridge Brass	1.0	800	50	45	110	40	Good edge, very slight discoloration

All parameters are starting points. The operator should verify the kerf width on a test coupon and fine‑tune the compensation offset in the WSX controller. For gold alloys with varying copper content (rose gold, 14K, 10K), slight adjustments to pulse energy may be required because copper increases the absorptivity and reduces the keyhole initiation threshold.

Key observations from the table:

• Fine silver has the highest reflectivity and thermal conductivity, demanding the highest power density and shortest pulses. The edge is matte white but free of oxide.
• Sterling silver (92.5% Ag) contains copper, which lowers the reflectivity slightly and improves the cut quality. The edge is brighter than fine silver.
• 18K gold alloyed with copper and silver cuts reliably. Pure 24K gold, if required, would need a slightly higher power density but is rarely laser‑cut in jewelry.
• Brass cuts cleanly, but the zinc content is volatile at high temperatures. The pulse duration is kept short and the cutting speed high to limit zinc evaporation and edge rounding.

Assist Gas Selection for Precious Metals

Nitrogen at 99.995% purity is the required assist gas for all precious metal cutting on the XC2030. It serves three functions:

1. Melt ejection. The 10–12 bar nitrogen jet clears the molten metal from the kerf. Without this, a recast layer builds up and narrows the kerf.
2. Oxidation suppression. Gold does not oxidize, but silver and brass do. Silver reacts with atmospheric oxygen to form a dark silver oxide film. Brass forms a zinc oxide layer that discolors the edge. Nitrogen displaces oxygen from the cut zone, leaving a bright, oxide‑free surface.
3. Cooling. The cold nitrogen gas convectively cools the surrounding metal, limiting the heat‑affected zone. This is especially important for thin gold sheet, where even a slight temperature rise causes warping.

Compressed air must never be used for silver or brass cutting. The oxygen in the air will tarnish silver instantly and produce a black, rough edge on brass. For gold, air is technically possible but produces a slightly matte edge and increases the recast layer. Nitrogen is the standard.

Workholding and Heat Management for Thin Sheet

Jewelry parts are often cut from sheets smaller than 100 × 100 mm and as thin as 0.3 mm. These sheets are prone to thermal buckling and to being moved by the assist gas jet. The following workholding practices are mandatory:

• Use a honeycomb or pin‑bed support table. The open structure allows the gas jet to pass through without reflecting back and lifting the sheet. The XC2030’s standard table provides this.
• For the thinnest gold (0.3 mm) and fine silver, use a low‑tack adhesive backing sheet. This holds the parts in place during cutting and prevents the gas jet from blowing away small, delicate components after they are cut free. The adhesive residue is removed with a brief solvent rinse after cutting.
• Enable the “thin sheet” height sensing mode in the WSX controller. This reduces the capacitive sensor gain and prevents the Z‑axis from oscillating on the flexible sheet. The XC2030’s sensor system is factory‑calibrated for this mode.
• The optional water‑bed table on the XC2030 is recommended for continuous production of silver and brass parts. The water conducts heat away from the sheet, keeping the bulk temperature below 35°C and eliminating warping.

Economic Impact: Recovery of Precious Metal Dust

One of the most overlooked economic factors in laser cutting jewelry is the recovery of precious metal dust. Conventional machining, filing, and sawing generate metal swarf that is collected and sold to refiners. Laser cutting vaporizes a small amount of metal, which is captured in the fume extraction filter. The filter media must be sent to a refiner for precious metal recovery. The XC2030’s sealed fume extraction system captures over 99% of the vaporized material in a HEPA filter cassette, which can be exchanged and shipped to a refiner. The value of the recovered gold, silver, and platinum group metals often offsets a significant fraction of the machine’s operating cost.

YIHAI LASER Application Note

The YIHAI LASER XC2030 precision laser cutter is a 200 × 300 mm flatbed system equipped with a single‑mode MOPA fiber laser (Maxphotonics, Raycus, or JPT options) and a WSX CNC controller preloaded with a “Precious Metals” parameter library. The library contains the cutting schedules listed above, plus additional settings for platinum, palladium, and filled gold alloys. The machine’s integrated fume extraction and optional water‑bed table make it suitable for continuous jewelry production. For jewelers evaluating the transition from hand‑fabrication or stamping to laser cutting, YIHAI LASER’s application laboratory processes sample metal sheets at no cost and returns cut samples with a complete process report, including edge micrographs and dimensional data.

Frequently Asked Questions

Can a CO₂ laser cut gold and silver jewelry?
No. CO₂ lasers operate at 10.6 µm, which is almost totally reflected by gold, silver, and copper alloys. A fiber laser at 1,070 nm, particularly a single‑mode source with a small spot size, is required to achieve sufficient power density to initiate a keyhole and cut these metals.

What laser power is needed to cut 0.5 mm gold sheet?
A single‑mode fiber laser delivering 550 W average power with 35 ns pulses cuts 0.5 mm 18K gold at 220 mm/s with a bright, dross‑free edge. The machine power rating (e.g., 1.5 kW) is higher than the average cutting power because the laser operates in pulsed mode and the rated power is the maximum continuous‑wave capability.

Why does silver tarnish during laser cutting?
Silver reacts with oxygen in the air to form silver oxide (Ag₂O), which is dark gray to black. Using nitrogen assist gas at 99.995% purity displaces the oxygen and prevents tarnishing. The cut edge remains matte white and requires no post‑cut cleaning.

Can the XC2030 cut platinum and palladium?
Yes. The XC2030’s preloaded parameter library includes settings for platinum and palladium. These metals have higher melting points and lower thermal conductivity than gold and silver, requiring higher pulse energy and slower cutting speeds. The single‑mode laser with adjustable pulse duration can process them with the same edge quality.

References

1. YIHAI LASER, XC2030 Precision Laser Cutting System Datasheet, 2026.
2. WSX CNC Controller User Manual, Shanghai Friends Electronic Technology Co., Ltd., 2025.
3. Maxphotonics, MFSC‑1500 Single‑Mode MOPA Fiber Laser Datasheet, 2025.
4. Steen, W.M., Mazumder, J., Laser Material Processing, 4th ed., Springer, 2010, pp. 279–305 (Reflectivity and keyhole dynamics of precious metals).
5. Davis, J.R. (ed.), Metals Handbook: Desk Edition, 2nd ed., ASM International, 1998, pp. 1115–1130 (Thermal and optical properties of gold, silver, and copper alloys).
6. ISO 9013:2017, Thermal cutting — Classification of thermal cuts.