Brass is one of the most widely used copper-based alloys in the world, prized for its machinability, corrosion resistance, and workability. Whether you’re sourcing 90/10 brass strips and coils for industrial fabrication, evaluating brass cups manufacturers for cartridge case production, or simply trying to understand the chemical composition of brass metal, this guide covers everything you need to know.
Brass is a metal alloy made primarily of copper (Cu) and zinc (Zn). Unlike bronze (copper + tin), brass gets its golden color and unique properties from the copper-zinc ratio. Small amounts of other elements lead, tin, iron, manganese, aluminum, or silicon are sometimes added to improve machinability, strength, or corrosion resistance for specific applications.
| Element | Percentage Range |
|---|---|
| Copper (Cu) | 55% – 95% |
| Zinc (Zn) | 5% – 40% |
| Lead (Pb) | 0% – 3% (for machinability) |
| Iron (Fe) | Trace – 0.35% |
| Tin (Sn) | Trace – 1% (for corrosion resistance) |
The exact brass composition determines the alloy’s color, hardness, ductility, and end use from decorative fittings to precision-engineered cartridge cases.
90/10 brass, also called gilding metal, contains 90% copper and 10% zinc. This composition strikes a balance between copper’s ductility and zinc’s strength, making it one of the most important alloys in cartridge and ammunition manufacturing.
Key properties of 90/10 brass:
Because of these properties, 90/10 brass strips and coils are the primary raw material used in manufacturing brass cups the intermediate product formed into cartridge cases.
Brass strips and coils are flat-rolled brass products supplied in continuous rolls or cut lengths, used across:
Strip and coil thickness, temper (hardness), and width are customized based on the downstream forming process deep drawing, stamping, or extrusion.
Brass cups are cup-shaped blanks punched from 90/10 brass strips or coils — the first stage in cartridge case manufacturing. The process typically follows these steps:
Reputable brass cups manufacturers maintain tight tolerances on wall thickness and composition consistency, since even minor variances in the 90/10 copper-zinc ratio affect pressure tolerance and case reliability during firing.
Brass foils are ultra-thin rolled brass sheets (often under 0.1mm), used in:
The brass foils industry relies on precision rolling mills capable of maintaining uniform thickness and surface finish at micron-level tolerances.
A brass weight calculator estimates the mass of brass strips, coils, sheets, rods, or cups using this general formula:
Weight (kg) = Volume (cm³) × Density (g/cm³) ÷ 1000
Brass density typically ranges from 8.4 to 8.73 g/cm³, depending on the copper-zinc ratio (higher copper content generally means higher density, closer to pure copper’s 8.96 g/cm³).
Example – Brass Strip: Weight = Length × Width × Thickness × Density
For coils, manufacturers also factor in coil width, strip thickness, and total coil length (derived from outer/inner diameter and core diameter) to estimate total tonnage per coil.
The copper-to-zinc ratio isn’t just a technical detail — it directly determines:
Manufacturers select specific brass grades (e.g., C220 gilding metal, C260 cartridge brass, C360 free-cutting brass) based on the mechanical and chemical demands of the final product.
Rashtriya Metal manufactures precision brass strips, coils, cups, and foils tailored to exact composition and tolerance requirements for industrial, electrical, and ammunition applications.
Brass is primarily composed of copper and zinc, typically ranging from 55–95% copper and 5–40% zinc, with trace elements like lead, tin, or iron added depending on the required application and grade.
90/10 brass refers to an alloy containing 90% copper and 10% zinc, also known as gilding metal. It’s known for high ductility and corrosion resistance, and is the standard material used to manufacture cartridge case cups.
In ammunition manufacturing, 90/10 brass strips and coils are punched into cups, then drawn and ironed through multiple stages to form finished cartridge cases used in bullets and shell casings.
Brass weight is calculated by multiplying the volume (length × width × thickness) by the material’s density, which typically ranges between 8.4 and 8.73 g/cm³ depending on the copper-zinc ratio.
Brass strips are flat-rolled brass in cut lengths, coils are continuous rolled brass wound for high-volume feeding into presses, and foils are ultra-thin rolled brass sheets (often under 0.1mm) used for shielding, decorative, and precision applications.