Brass laser cutting

Thin brass cuts cleanly with nitrogen; thicker sections need slower speeds and careful focus to avoid dross. Lead-bearing brass produces fume that must be extracted. The cut edge on brass is usually acceptable for electrical use but may need deburring where a contact surface or a coating follows.

The commercial consequence is that brass is priced on its own material line, not blended into a steel rate. Material grade, thickness, tolerance and finish are quoted separately from conversion, so a change of specification is visible in the price.

Ganesh quotes to the drawing first and to ISO 2768 general tolerances where the drawing is silent. For brass laser cutting, the practical starting points are in the table below. They are starting points, not a guarantee: the part geometry, thickness and fixturing decide what can actually be held, and the quotation states the tolerance offered.

Cut quality depends on assist gas, focus position and nozzle condition more than on the headline power; nitrogen gives an oxide-free edge on stainless and aluminium. Lead-bearing CuZn39Pb2 machines and shears more freely but is restricted in some markets under RoHS and REACH, so the grade has to be chosen against the destination market, not only the drawing. The route is quoted as one sequence so the customer does not have to coordinate a cutter, a former, a welder and a coater.

Laser cutting is the wrong process where the part needs a coined or coined-and-formed profile; that is a press job regardless of volume.

A manufacturability review before quotation is the cheapest place to find this out. Send the drawing, material, finish and annual quantity and the review comes back in writing.

• Busbar links
• Terminal plates
• Decorative panels
• Gaskets and spacers

Use laser cutting when the design is still moving, when the volume does not justify a tool, or when the part is large enough that a press tool would be uneconomic. It is also the right first operation for a part that will be formed and welded, because a nest can carry several different parts at once. It stops being the cheapest route when a flat part with stable geometry runs in high volume, at which point a blanking die wins on piece price and generally on edge quality too. For brass the practical constraint is alloy restriction and tarnish: the grade has to satisfy the destination market's substance rules, and the surface needs protection if it must stay bright. Brass is usually a volume material by nature, so the process decision is often already made by the part family; the real choice is the alloy and the temper, and whether the destination market permits the lead content.

Send a DXF with the cut contour on its own layer, no duplicate or open entities, and a drawing that states material grade, thickness, tolerance and finish. State which edges are cosmetic and which are weld prep, because the assist gas and the deburring requirement follow from that. If the part is long, say the maximum length: a 4,450 mm panel that fits the 40 ft bed in one piece does not need a joint.

Inspection covers the cut contour against the DXF, overall size, hole position, squareness and edge condition. Burr is checked visually and by touch on cosmetic edges. Material is traceable to the mill certificate where the customer requires it. First article parts are inspected before a repeat run.

Cost splits into material, machine time, handling, deburring and any secondary operation. Material is quoted at the prevailing rate for the grade and thickness, on the nest area consumed rather than the finished part area. Machine time is set by cut length, thickness, pierce count and nesting density. Deburring is a separate operation and is often the line that surprises a buyer. On brass, material is quoted as its own line at the prevailing rate for the grade and thickness, so a change of specification is visible rather than hidden in a blended rate.