DESCRIPTION Graphite electrodes nipples are used to connect two or more electrodes into column. And the purpose of that is to realize continuous use of electrodes in electric arc furnace steelmaking process. Nipples, with conventional external threads surface, are the important clamping device to extend the electrode length. Doing this avoids the unproductive consumption in smelting. As a technical manufacturer, we know that the mismatch between the graphite electrode body and the nipple will lead to the electrode breaking during use. This not only just is an unproductive consumption in smelting, but also increases the amount of carbon in the molten steel. For these reasons, all electrode nipples are produced by our factory, not purchased. FEATURE High bulk density, precision thread accuracy. Check the tolerance of nipples one by one. Bending strength limits are measured. High machining accuracy, good surface finishing. Outstanding resistance to breakage. Original factory production, not outsourcing. APPLICATION SPECIFICATION Table 1 Technical Specification of Graphite Electrode Nipple   Item Resistance Density Flexure Strength Elastic Modulus Ash Content CTE (≤, µΩ·m) (≥, g/cm3) (≥, MPa) (≤, GPa) (≤, %) (100 °C – 600 °C) (≤, 10-6/°C) Regular power 6.0 1.72 15 14 0.3 2.5 High Power 5.0 1.75 18 18 0.3 2.2 Ultra High Power 4.2 1.78 20 22 0.3 1.4 Dimensions of nipple & socket Table 2: Dimensions of Nipple & Sockets (TPI 3) Electrode Dia. Nipple Designation Nipple Socket Major Dia. Length Pitch Dia. Depth Thread Length (mm) (mm) (mm) (mm) (mm) (inch) (mm) d1 l1 d4 l2 l3 9 225 139T3N 139.7 203.2 135.49 107.6 103.6 10 250 155T3N 155.57 220 151.36 116 112 12 300 177T3N 177.16 270.9 172.95 141.5 137.5 14/16 350/400 215T3N 215.9 304.8 211.69 158.4 154.4 14/16 350/400 215T3L 215.9 355.6 211.69 183.8 179.8 16/18 400/450 241T3N 241.3 338.7 237.09 175.3 171.3 16/18 400/450 241T3L 241.3 355.6 237.09 183.8 179.8 20 500 273T3N 273.05 355.6 268.84 183.8 179.8 20 500 273T3L 273.05 457.2 268.84 234.6 230.6 22 550 298T3L 298.45 457.2 294.24 234.6 230.6 * Pin pitch diameter d2 is equal to socket pitch diameter d4. * Socket minor diameter d3 is equal to pitch diameter d4 minus 3.16 mm. * Other combinations of nominal diameter and joint are to be agreed upon between the supplier and user. Table 3: Dimensions of Nipple & Sockets (TPI 4) Electrode Dia. Nipple Designation Nipple Socket Major Dia. Length Pitch Dia. Depth Thread Length (mm) (mm) (mm) (mm) (mm) (inch) (mm) d1 l1 d4 l2 l3 9 225 139T4N 139.7 177.8 136.54 94.9 90.9 10 250 152T4N 152.4 190.5 149.24 101.3 97.3 12 300 177T4N 177.8 215.9 174.64 114 110 14 350 203T4N 203.2 254 200.04 133 129 14 350 203T4L 203.2 304.8 200.04 158.4 154.4 16 400 222T4N 222.25 304.8 219.09 158.4 154.4 16 400 222T4L 222.25 355.6 219.09 183.8 179.8 18 450 241T4N 241.3 304.8 238.14 158.4 230.6 18 450 241T4L 241.3 355.6 238.14 183.8 179.8 20 500 269T4N 269.88 355.6 266.72 183.8 179.8 20 500 269T4L 269.88 457.2 266.72 234.6 230.6 22 550 298T4N 298.45 355.6 295.29 183.8 179.8 22 550 298T4L 298.45 457.2 295.29 234.6 230.6 24 600 317T4N 317.5 355.6 314.34 183.8 179.8 24 600 317T4L 317.5 457.2 314.34 234.6 230.6 * Pin pitch diameter d2 is equal to socket pitch diameter d4. * Socket minor diameter d3 is equal to pitch diameter d4 minus 3.16 mm. * Other combinations of nominal diameter and joint are to be agreed upon between the supplier and user. Table 4: Standard Electrode Sizes & Nipple Weights Electrode Standard Weight of Nipples Nominal Electrode Size TPI 3 TPI 4 Dia. × L T3N T3L T4N T4L inch mm lbs kg lbs kg lbs kg lbs kg 14 × 72 350 × 1800 32 14.5 - - 24.3 11 - - 16 × 72 400 × 1800 45.2 20.5 46.3 21 35.3 16 39.7 18 16 × 96 400 × 2400 45.2 20.5 46.3 21 35.3 16 39.7 18 18 × 72 450 × 1800 62.8 28.5 75 34 41.9 19 48.5 22 18 × 96 450 × 2400 62.8 28.5 75 34 41.9 19 48.5 22 20 × 72 500 × 1800 79.4 36 93.7 42.5 61.7 28 75 34 20 × 84 500 × 2100 79.4 36 93.7 42.5 61.7 28 75 34 20 × 96 500 × 2400 79.4 36 93.7 42.5 61.7 28 75 34 20 × 110 500 × 2700 79.4 36 93.7 42.5 61.7 28 75 34 22 × 84 550 × 2100 - - - - 73.4 33.3 94.8 43 22 × 96 550 × 2400 - - - - 73.4 33.3 94.8 43 24 × 84 600 × 2100 - - - - 88.2 40 110.2 50 24 × 96 600 × 2400 - - - - 88.2 40 110.2 50 24 × 110 600 × 2700 - - - - 88.2 40 110.2 50 Table 5: Coupling Torque Reference for Nipple & Electrode Electrode Diameter inch 8 9 10 12 14 16 18 20 22 24 mm 200 225 250 300 350 400 450 500 550 600 Easing Moment N.m 200–260 300–340 400–450 550–650 800–950 900–1100 1100–1400 1500–2000 1900–2500 2400–3000 Below chart is the matching relationship between electric furnace capacity, transformer power load and electrode size. Furnace Capacity Inner Dia. Transformer Capacity (MVA) Electrode Dia. t m RP HP UHP mm 10 3.35 5 7.5 10 300/350 15 3.65 6 10 12 350 20 3.95 7.5 12 15 350/400 25 4.3 10 15 18 400 30 4.6 12 18 22 400/450 40 4.9 15 22 27 450 50 5.2 18 25 30 450 60 5.5 20 27 35 500 70 6.8 22 30 40 500 80 6.1 25 35 45 500 100 6.4 27 40 50 500 120 6.7 30 45 60 550/600 150 7 35 50 70 600 170 7.3 - 60 80 600 200 7.6 - 70 100 600/700 250 8.2 - - 120 700 300 8.8 - - 150 700