Tungsten bar is mainly used to found ingredient of material, cutter and heads, tungsten wire for lights instruments, electric contact points and conductor of heat, crankshaft and cylinder barrel of advanced automobile, ingredient of kinds of heat-resistant steel. Also used for making special steels, to make guns, artillery rockets, satellite airplane and ship. Tungsten bars have a luster rather like that of silver in uniform color. Though the whole tungsten bars may slightly curve, the maximum height of the bend should not be more than 7mm.
The most popular application of tungsten bar is in steel making industry. Tungsten bars are used to improve the property of steel.
Tungsten bar with impurities is used to procedure bulb filaments or electron tube filaments, which are guaranteed to have remarkable resistance to high temperature.
Grade of tungsten bar:
In reference to different chemical components and applying requirement, the grades of products are divided into four categories:W1, W2 , W3, W4.
Dimensions of tungsten bar:
(10-14)×(10-14)×(400-600) mm
The length of the finished tungsten bar for W1, W2, and W3 should not be less than 300mm, and that for W4 should not be less than 30mm.
Appearance of tungsten bar:
The appearance of tungsten bar turns to be metallically gray or dark gray. Hygroscopy is not allowed on the appearance of W1 , W2, and W3 tungsten bars.
Surface State of tungsten bar:
Any oxidation, contamination, and severe excessive fusion, bubbling, delamination, or crack is not allowed for product W1. Camber should be no more than 10mm. Any excessive fusion, bubble, delamination, crack, surface bulky crystallization or severe oxidation &contamination are not allowed for products W2 and W3. The length of the spalls should not be more than 8mm, width no more than 3mm, depth no more than 1mm; The diameter of mechanical pitting should not be more than 1mm, depth no more than 0.5mm; Camber should be no more than 4mm.
Any oxidation or contamination is not allowed for product w4.
The cartridge of the vertical sintering part should be cut off, and the section is not allowed to be loose or intermingled.
Physical property of tungsten bar:
The density for W2, W3 tungsten bars is more than 17.5g/cm3.
Measured data for the section grain size of W2, W3 can be provided. If the buyer has any other special demand, it can be discussed on the base of mutual negotiation.
Quality Guarantee:
The buyer should take an acceptance inspection on the goods in accordance with this standard in three months from the day of getting the goods. If the inspecting results do not meet the grade criteria set on the Quality Guarantee, the products is still regarded as unqualified after the unsuccessful mutual test.
Package:
The products should be package in wooden boxes with inner shaped foam, 6-12 pieces and 40kgs max. net each.
Transportation:
During the transportation, the goods should be moisture proof and clear of violent collision.
Storage:
Storage place: dry, ventilated, acid & alkali proof, anti-oxidant. The storage time should be limited in six months.
