1,183,771. Bait for drawing glass tubes or rods. FUJI SHASHIN FILM K.K. 28 Nov., 1967 [2 Dec., 1966], No. 54098/67. Heading C1M. A bait, for the upward drawing of glass tubes or rods more than 40 mm. in diameter and of linear coefficient of thermal expansion of less than 50 x 10-7/‹C., is made from a glass having a coefficient of thermal expansion of less than 60x10-7/‹C. and greater than 6x10-7/‹C. at least in the portion which contacts the molten glass. Preferably, the whole of the bait is made from such a glass and preferably has a coefficient of expansion in the range 35 x 10-7 to 50 x 10-7/‹ C. By using a bait having a coefficient of,expansion close to that of the glass of the tube or rod the possibility of fracture occurring at the glass-bait join during drawing is minimized.
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