MS round bars of 32.00, 36.00 and 38.00 mm are used to fabricate adjustable U jack with 4 TPI acmesquare threads. U head is fabricated out of 100 x 6 or 5 mm MS flat having requisite height and malleable cast iron cup type lightdouble handle duty nut. Sizes available are 350, 450, 550 and 600 mm of bar length.