29HK / Kovar Plate/Rod Fe Ni alloy barGeneral Description
Kovar is a nominal 29%Ni-17%Co-54%Fe alloy that is a well-known
glass-sealing alloy suitable for sealing to hard glasses. Kovar has
a nominal expansion coefficient of approximately 5 ppm/°C and
inflection temperature of ~450 °C (840 °F).
Kovar (ASTM F15) has been used for making hermetic seals with the harder Pyrex
glasses and ceramic materials. This alloy has found wide
application in power tubes, microwave tubes, transistors, and
diodes. In integrated circuits, it has been used for the flat pack
and the dual-in-line package.
Chemical Composition| Grade | C% | P% | S% | Mn% | Si% | | Cu% | Cr% | Mo% | Ni% | Co% | Fe% |
| Kovar | Max 0.03 | Max 0.020 | Max 0.020 | Max 0.50 | Max 0.30 | | Max 0.20 | Max 0.20 | Max 0.20 | 28.5-29.5 | 16.8-17.8 | Bal. |
| Grade | UNS | Werkstoff Nr. | ASTM |
| Kovar | K94610 | 1.3981 | F15 | |
| Grade | Density | Melting Point |
| Kovar | 8.17 g/cm3 | 1449°C |
| Grade | Tensile Strength N/mm² |
| Soft | 1/4 Hard | 1/2 Hard | 3/4 Hard | Full Hard |
| Kovar Strip | <570 | 520-630 | 590-700 | 600-770 | >700 |
| Kovar Wire | <585 | 585-725 | 655-795 | 725-860 | >860 |
| Alloy | Linear Coefficient of Thermal Expansion ā,10-6/ºC |
| 20-200ºC | 20-300ºC | 20-400ºC | 20-450ºC | 20-500ºC | 20-600ºC | 20-700ºC | 20-800ºC |
| Kovar | 5.9 | 5.3 | 5.1 | 5.3 | 6.2 | 7.8 | 9.2 | 10.2 |
Size Range:*Sheet---Thickness 0.1mm~40.0mm, width:≤300mm,Condition: cold
rolled(hot), bright, bright annealed
*Round Wire---Dia 0.1mm~Dia 5.0mm,Condition: cold drawn, bright,
bright annealed
*Flat Wire---Dia 0.5mm~Dia 5.0mm,length:≤1000mm,Condition:flat
rolled, bright annealed
*Bar---Dia 5.0mm~Dia 8.0mm,length:≤2000mm,Condition:cold
drawn,bright, bright annealed
Dia 8.0mm~Dia 32.0mm,length:≤2500mm,Condition:hot rolled,bright,
bright annealed
Dia 32.0mm~Dia 180.0mm,length:≤1300mm,Condition:hot forging,peeled,
turned, hot treated
*Capillary---OD 8.0mm~1.0mm,ID
0.1mm~8.0mm,length:≤2500mm,Condition: cold drawn, bright, bright
annealed
*Pipe---OD 120mm~8.0mm,ID 8.0mm~129mm,length:≤4000mm,Condition:
cold drawn, bright, bright annealed
