ineer tube 16.00-20 1.Wear and heat resistance 2. ... 00-7, 4.00-8, 4.00-10, 4.00-12, 4.00-14, 4.00-16, 4.50-10, 5.00-10, 5.00-12, 5.00 ... -14, 5.50-12, 5.50-13, 5.50-17, 6.00 ... -12, 6.00-14, 6.00 ... -16, 6.50-16, 7.00-16, 7.50-16, ... 7.50-20, 8.00-16, 8.30-20, 8.30-22, 8 ...