the seating chart fixing frame, the passageway isolating blocks and the small movable seating holes are made of plastics and are fixed together; the small square movable seating block can be installed in the small movable seating hole; and the movable student seating chart is simple in structure...
A transformer or generator is used to supply current. The depth to which the metal is melted and deposited is called the depth of fusion. To obtain a better depth of fusion, the electrode is kept at 70° inclination to the vertical. The electrode used in arc welding is generally coated ...