H62 Brass Chemical Composition and Standards | 62% Copper Alloy Complete Guide

Introduction

H62 is a common brass alloy with an average copper content of 62%, balanced with zinc (Zn) as the primary alloying element. In China's GB standard system, the "H" prefix denotes ordinary brass (黄铜), and the number indicates the nominal copper percentage.

H62 belongs to the alpha-beta (α+β) two-phase brass family. The combination of copper's excellent electrical conductivity and ductility with zinc's strength and durability makes H62 a versatile, cost-effective engineering material. It is one of the most widely used brass grades for pressure forming, stamping, drawing, and general hardware manufacturing.

For applications requiring superior machinability on automatic lathes, see our guide on C3604 free-cutting brass, which contains lead additions for enhanced chip-breaking.

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Chemical Composition

Reference: GB/T 5231 (Wrought Copper and Copper Alloys)

Grade Cu (%) Fe (%) Pb (%) Sb (%) Bi (%) P (%) Zn (%) Total Impurities (%)
H62 60.5–63.5 ≤ 0.15 ≤ 0.08 ≤ 0.005 ≤ 0.002 ≤ 0.01 Balance ≤ 0.5

Key compositional notes:

  • Copper (Cu, 60.5–63.5%): Primary element providing electrical conductivity, corrosion resistance, and ductility.
  • Zinc (Zn, balance ~36–39%): Increases strength and hardness; higher Zn content than H68 or H70 gives H62 better strength at lower cost.
  • Lead (Pb, ≤ 0.08%): Controlled as an impurity (not intentionally added, unlike C3604). H62 is not a free-machining brass.
  • Bismuth (Bi, ≤ 0.002%) and Antimony (Sb, ≤ 0.005%): Tightly controlled to prevent hot shortness and embrittlement during hot working.

Physical Properties

Property Value
Density ~8.5 g/cm³
Melting Point 905–910 °C
Thermal Conductivity 116 W/(m·K)
Electrical Conductivity ~28 %IACS
Hardness (Brinell) 55–75 HB
Hardness (Vickers) ~60–80 HV
Elongation at Break 30–40%

Common Brass Grades Comparison

Grade Cu (%) Zn (%) Key Feature Typical Use
H62 60.5–63.5 Balance Good strength, cost-effective, pressure formable Hardware, stampings, mechanical parts
H68 67–70 Balance Better ductility, deep drawing Cartridge cases, complex drawn parts
H70 69–72 Balance Excellent cold workability Radiator fins, heat exchanger tubes
C3604 (HPb59-3) 57–61 Balance Free-machining (Pb 1.8–3.7%) CNC turning, automatic lathe parts

Applications of H62 Brass

  • Hardware & Building Fittings — door handles, hinges, locks, window fittings, and decorative architectural hardware
  • Electronics & Electrical — wire and cable terminals, connectors, plugs, sockets, and electronic component housings
  • Mechanical Components — bushings, sleeves, gears, and general mechanical fittings
  • Marine Hardware — door and window fittings, decorative railings, and marine hardware in mildly corrosive environments
  • Stamped & Drawn Parts — H62 is well-suited for cold stamping, deep drawing, and press forming of complex shapes
  • Plumbing & Valves — valve bodies, pipe fittings, and plumbing hardware

Fabrication Characteristics

Formability (Pressure Working)

H62 has excellent cold and hot workability. It can be processed by cold drawing, stamping, deep drawing, bending, roll forming, and casting. The α+β two-phase structure provides a good balance of strength and ductility for pressure forming operations. It is one of the most commonly used brass grades for stamped hardware components.

Machinability

H62 has moderate machinability. It can be turned, milled, and drilled, but chip-breaking is less efficient than free-machining grades. For high-volume CNC turning or automatic lathe operations, C3604 free-cutting brass (with 1.8–3.7% Pb) is the preferred choice due to its significantly superior chip-breaking characteristics.

Weldability

H62 can be welded by brazing and soldering. Fusion welding is generally not recommended due to zinc volatilization at elevated temperatures. Brazing with silver-based or copper-phosphorus filler alloys is the standard joining method.

Corrosion Resistance

H62 has good corrosion resistance in air and water environments. However, it is susceptible to dezincification in certain aggressive environments (stagnant water, acidic media) and stress corrosion cracking (SCC) in ammonia-containing atmospheres. For marine or highly corrosive environments, higher-copper grades or special brass alloys are recommended.

Surface Treatment

H62 accepts a wide range of surface treatments including electroplating (nickel, chrome, gold), lacquering, and chemical polishing. Its warm golden color also makes it suitable for decorative applications without surface treatment.


Standards reference: GB/T 5231 | GB/T 2040 (plate/sheet) | GB/T 1527 (tube) | ASTM B36 (equivalent: C26800 / C27000)

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