... melting point ,steady electric arc ,without self-consume .Tungsten increasing 0.15-4% Tho 2 ,Zro 2 ... quality of welding seam is high. 2. Export tungsten electrodes execute ISO 6848 international standard and AWS5.12.3 ... . Flat degree :not large 0.5% length of electrodes. 5. Quality of surface :smooth ,clear ,no ... and other impurity.6. The end surface of electrodes should be even ,smooth and no burrs , ...