Nichrome/Tophet “A”

Nominal Composition

Carbon 15% Max
Manganese 5% Max
Sulfur 0.1% Max
Silicon 0.5-1.5% Max
Chromium 19-21%
Nickel (+Cobalt) 77-79%
Iron 1.0% Max

Nichrome/Tophet “A” is a nickel-chromium resistance alloy for operating temperatures up to 2150° F. It is non-magnetic, highly corrosion resistant and has a lower coefficient of resistance than other heater element alloys. Typical Applications for the material include flat irons, ironing machines, quartz tube heaters, cartridge elements, etc. The lack of reactivity to MgO refractories make it the most suitable alloy for enclosed heater elements especially in higher temperature ranges.

Typical Mechanical Properties

Ultimate Tensile Strength:
Hard Temper 200,000 PSI
Stress Relieved 175,000 PSI
Annealed 100,000 PSI
Modulus of Elasticity
(x 10e6 PSI)
31
Magnetic Response Non-magnetic

Typical Physical Properties

Density .304 lbs/cu in
Melting Point 2552° F Approximately
Specific Gravity 8.41
Electrical Resistivity @ RT 650 ohm/cir mil/ft
Thermal Expansion Coefficient
70-200°F 7.3 x 10-e6
201-1500°F 9.6 x 10-e6
Thermal Conductivity  0.113 W/cm/°C

Forms

H. Cross Company can provide Nichrome/Tophet “A” in wire, ribbon, strip, sheet and foil sizes to suit your particular needs. Please refer to our Typical Dimension and Tolerances page for general size ranges of products. If you do not see your required size list Contact Us by or email phone for further information or assistance.