Performance Overview
H96 is the lowest-zinc of the common brasses, with a copper content of 95 to 97 percent and zinc making up the remainder. In rod and tube form it behaves as a near-copper material: strong enough to be handled and machined, but the weakest of the ordinary brasses and the closest of them to unalloyed copper in conductivity, colour and corrosion response. Rod is used mainly for machined components and for forming into fittings, while tube serves heat transfer, fluid handling and waveguide duty. Understanding its mechanical behaviour by temper and by diameter is essential, because H96 is one of the grades where the difference between the soft and hard conditions is large.
Mechanical Properties
| Property | Value | Condition |
|---|---|---|
| Tensile strength, rod | 205 to 275 MPa | Y, hard, 3 to 80 mm diameter |
| Tensile strength, rod | About 200 MPa | M, annealed |
| Elongation | 3 to 45% | Temper dependent, up to 45% soft |
| Hardness | About 45 to 105 HV | Tube and rod, temper dependent |
Three points follow. First, the difference between the annealed and hard conditions is modest in absolute terms, at roughly 75 MPa, compared with the much larger spread seen in H62. Second, the grade is not a structural material: designs that depend on high yield strength should move to a lower-copper brass rather than specify a harder temper, since H96 gains little strength and loses ductility quickly. Third, elongation in the soft condition is very high, which is exactly why the grade is chosen for severe forming and for cold heading.
Fatigue Behaviour
Fatigue strength scales with tensile strength. For H96 the fatigue limit is approximately 50 to 60 percent of the tensile strength, and under a stress amplitude of about 140 MPa the material sustains more than ten million load cycles without fracture. That behaviour makes the grade usable in vibrating service such as instrument and waveguide fittings and in thin-walled tube subject to pressure pulsation, provided the stress amplitude stays well below the tensile strength and the component has been stress relieved after forming.
Physical Properties and Corrosion Performance
| Property | Value |
|---|---|
| Density | 8.85 g/cm³ |
| Electrical conductivity | About 56% IACS |
| Thermal conductivity | About 230 W/(m·K) |
| Melting range | About 1050 to 1075 degrees Celsius |
The high copper content gives H96 excellent resistance to atmospheric corrosion, to fresh water and to some dilute acidic environments, and the single-phase alpha structure means it has no tendency to stress corrosion cracking in normal service. It has good thermal and electrical conductivity, which makes it suitable for conductive and heat-transfer components. It is not, however, a seawater alloy: chloride-bearing service requires a tin-bearing brass, an aluminium bronze or a cupronickel. Where the working fluid carries ammonia or ammonium compounds, even an alpha brass can suffer cracking if residual stress is present, so stress relief annealing after cold forming is good practice.
Applications
Construction: building profiles and window and door frame components that benefit from the warm colour and corrosion stability of a high-copper brass.
Mechanical engineering: machined parts, valve bodies and trim, pipe fittings and bolts.
Bearings and bushes: medium-speed, heavy-load bearing applications that benefit from automatic centring, insensitivity to shaft deflection and uniformity of bearing pressure.
Electrical and electronic equipment: conductive parts, connectors, relay components, heat sinks and lead frame material.
Heat transfer: radiator and heat exchanger tube in low-chloride service.
Communications: double-ridged rectangular waveguide tube, where the excellent plasticity of H96 supports the required forming operations.
Two processing notes are worth keeping on the shop floor record. First, H96 solders, brazes, welds, forges and tins readily in the soft condition, but welding thin tube demands good fixture support because the material is soft and distortion-prone. Second, because the grade is soft, machined rod components need sharp tooling and light feeds; work hardening is limited, so a heavy finishing cut will produce smearing rather than a clean chip.
FAQ
Q: What is the tensile strength of H96 brass rod?
Bar in the hard condition at 3 to 80 mm diameter is typically 205 to 275 MPa, and annealed bar is around 200 MPa. The actual figure depends on diameter and delivery state.
Q: Is H96 brass strong enough for structural use?
No. It is the weakest of the common brasses. Structural and load-bearing designs should use a lower-copper brass with higher yield strength.
Q: What is the fatigue limit of H96 brass?
Approximately 50 to 60 percent of the tensile strength, and more than ten million cycles at a stress amplitude around 140 MPa.
Q: What is the density and conductivity of H96 brass?
Density is 8.85 g/cm³, electrical conductivity is about 56 percent IACS and thermal conductivity is about 230 W/(m·K).
Q: Does H96 brass suffer stress corrosion cracking?
It has no tendency to stress corrosion cracking in normal service, but residual stress from cold forming should still be relieved where ammonia or ammonium compounds are present.
Q: Can H96 tube be used for seawater or marine duty?
No. Chloride-bearing service requires an alloy designed for it, such as a tin-bearing brass, an aluminium bronze or a cupronickel.
