Alloys: LEONI Histral® H72

Copper based alloy, CuSn0.3

Technical data

Nominal values: Tempered Hard
Resistivity* (Ohm mm2/m) 0.0216 0.0240
Electrical Conductivity* (% IACS) 80 74
Tensile Strength* (N/mm2) 250 600
Elongation* (%) 20 1
Temperature Coefficient of Resistance (1/°C) 0.00290 0.00290
Density (g/cm3) 8.9 8.9

* Data depend on coating conditions, degree of cold working and thermal treatments during manufacturing process 


  • LV112-4 DRAFT
  • DIN CEN/TS 13388


  • Coating: Bare, Silver, Nickel, Tin, Gold
  • Temper: Tempered or hard
  • Single end conductors
  • Stranded conductors
  • Bunched conductors
  • Concentric lay conductors
  • Single end size ≥ 0.025 mm (AWG 50)
  • Other diameters or special constructions are available

** Depending on material combination & construction

Excellent properties

High electrical conductivity

Due to the alloy portion in LEONI Histral® H72 being very low, there is just a slight decrease in resistance if compared with pure copper. Thus, the material preserves its high electrical conductivity while also featuring a great mechanical strength. Therefore, the material lends itself perfectly to strands where the very low diameter or cross-section must not lead to inadequate tensile strength.

Good mechanical strength

LEONI Histral® H72 is counted among the so-called „low-alloyed copper products“, the copper portion of which is 99.7 % of copper, with no more than the remaining 0.3 %  covered by alloy additives (mainly tin in this case). Having been hard-drawn, its mechanical properties even improve, without the very good electrical qualities being impaired. This phenomenon allows for a significant reduction of cross-sections. Consequentially, Histral® H72 lends itself well to applications in which reduced weight plays a primary role. A prime example for this are signal cables, but also shielding braids, both of which require an above-average mechanical strength in order for the actual conductor to be sufficiently protected.

Flex Life properties

Alloys are usually employed in hard condition. LEONI Histral® H72 boasts excellent Flexlife properties, which ensure highest stability in any environment that is exposed to a lot of vibration and motion.

Contact properties

The crimp qualities of LEONI Histral® H72 correspond to those of pure copper in hard condition. However, the tools applied have to be adapted to the lower cross-sections.

Reduced weight

The outstanding properties of LEONI Histral® H72 translate into much lower cross-sections supporting the same breaking load if compared to pure copper. For a breaking load of 70 N a pure copper strand must have a cross-section of 0.35 mm2, whereas the comparable value for a strand made out of  Histral® H72 is 84 N at a cross-section of only 0.13 mm2, by means of which a weight reduction by 63 % can be achieved!
Using weight as a reference value, a copper strand requires 0.0445 (g/m) per each 1 N of breaking load, with Histral® H72 attaining the same breaking load at a weight of just 0.0136 (g/m).

Thermal stability

Pure copper in hard condition is susceptible to re-crystallization even at room temperature, at which it already begins to soften again resulting in a loss of mechanical strength. Adding on small quantities of alloys will suffice to vastly increase the point of re-crystallization of hard-drawn materials so that the greater strength is maintained in the event of higher ambient temperature, too. LEONI Histral® H72 has a much better thermal stability than pure copper. Hence, it is also suited for those applications that are subjected to elevated temperatures.


LEONI Histral® H72 has a slightly higher resistance than pure copper, while still boasting a conductivity of 80 % IACS (in soft condition).

Special applications

Automotive industry

The emphasis is more and more shifting towards environmental protection and husbanding of resources, with the focus revolving around the minimization of weight and consumption accompanied by heightened standards of safety and comfort. The growing use of electronic assistance systems constitutes a major step in this direction, which entails an increasing demand for signal cables. At the same time, the space accorded to cable harnesses is declining because of optimized safety systems. Signal cables made from LEONI Histral® H72 have the potential to render an important contribution to overcoming this predicament.

Data cables / Signal cables

Its small alloy portion reduces the resistance value of  LEONI Histral® H72 no more than a little, as compared with pure copper. Thus, the very good electrical conductivity of the material remains unaffected whilst its excellent mechanical strength persists. This makes it a perfect fit for data cables and signal cables featuring very low diameters and cross-sections, but also a sufficient tensile strength.

Automation technology / Industrial applications

LEONI Histral® H72 boasts excellent Flexlife properties, which ensure highest stability in any environment that is exposed to a lot of vibration and motion.


The connection cables of loudspeaker membranes are exposed to extremely strong vibrations. LEONI Histral® H72 lends itself well to this application owing to its great mechanical strength in combination with a very good conductivity, in particular as a substitute for cadmium-containing alloys used in the past.


On account of its outstanding mechanical properties, LEONI Histral® H72 will not pose any problems when processed downstream into wires as fine as 0.025 mm (AWG 50). It keeps its conductivity level and remains an alloy that is highly suitable for being electro-plated.

Quality & Environment

There are no restrictions whatsoever on using Histral® H72 in the automotive sector.

Custom solution services

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