Brass CW614N (CuZn39Pb3)

Physical properties

Laser processing

Extremely toxic. CW614N contains 3% lead (Pb). Lead fumes (lead oxide) are neurotoxic and carcinogenic, causing cumulative and irreversible neurological damage even at low doses. Zinc fumes are also present. Extraction with HEPA+activated carbon is mandatory. Processing without extraction in a closed room is illegal in many countries. Machine operators must wear a mask with P3 filter for lead.

CO₂: Not cuttable. CW614N is a free-machining brass with 3% lead. Same CO2 reflection limitations as CW508L. Never direct a CO2 beam at a polished brass surface without a protective absorbent coating and approved safety bypass on the machine's optical control system.

Diode: Marginally possible on painted surface with 20W+ diode, but the lead content (3%) makes the material significantly denser and thermally absorbent. Results are slightly worse than CW508L. The lead tends to vaporise unevenly, creating pitted edges. Not recommended.

Fiber: Fiber laser cuts CW614N excellently up to 4mm. The 3% lead content improves cut quality because the lead absorbs heat, forms low-melting micro-particles, and acts as a lubricant in the cut channel. Excellent edge finish with nitrogen assist. Fibre engraving gives a permanent, dark mark that can be varied by parameters. CW614N is the best brass for fiber laser work.

CNC / milling processing

Excellent CNC machinability. This is the traditional 'free-machining brass' used for screw-turned parts. The lead acts as a chip breaker and internal lubricant. It is the easiest brass alloy to mill; use standard high-speed parameters. Minimal burr; long, well-broken chips. Choose CW614N when production speed and surface finish are critical.

Post-processing

Sanding: Sands easily, very similar to CW508L. The lead content provides slight lubrication but the fine dust is toxic. Use wet sanding or extraction during dry sanding. Never leave lead-containing dust in the work area: vacuum immediately with a HEPA filter-equipped cleaner.

Primer: mandatory. Same recommendations as CW508L. Metal primer for non-ferrous metals. Some primers may show slight discolouration over time due to lead surface migration.

Gluing: Similar to CW508L, but the lead content may slightly reduce epoxy strength on non-sanded surfaces. Sand the joint area before gluing or use anaerobic adhesives (Loctite-type) designed for metal threads.

Seasoning: Same as CW508L. Storage in dry conditions. Wash hands thoroughly after contact due to lead content. Do not use for food-contact or skin-contact products.

Over time: Similar darkening patina to CW508L. Lead can cause a slightly faster dark-grey initial oxidisation. If left unprotected, lead-oxide forms a bloom-like surface haze. More critical to seal with clear lacquer for aesthetic projects.

Common defects

• Immediate oxidation and dark fingerprints on the surface if handled with bare hands without gloves
• Dispersion of fine metallic dust containing lead during fast dry machining (extractor recommended)

Safety

Recommended PPE: mask_p3, eye_protection

Lead is toxic in all forms. Lead-containing dust and fumes are cumulative poisons. Always wear P3/FFP3 mask and extract. Wash hands after handling. Do not eat, drink, or smoke in the workspace. CW614N is not RoHS-compliant: do not use for products sold in the EU for consumer use.

Availability and formats

Commercial formats: flat bars, round bars for turning, sheets 1–10mm

Related materials

Sources

• EN 12164 — Copper and copper alloys (free-cutting brass specifications)
• MatWeb — CW614N Brass Datasheet