An improved method and apparatus for shearing hot rolled metal blanks in which shear blades having a particular shape are used to shear the metal blank to produce a tapering transverse edge configuration having a longitudinally extending control portion relative to the top and bottom surfaces of the blank thereby to minimize laminating of the sides in subsequent rolling operations.
A method and apparatus are taught for cutting a sheet material comprising the steps of engaging a first side of the laminated web structure with a crack initiator having a high rake angle, the crack initiator extending from a first cutter base having a low rake angle; simultaneously engaging a second side of the laminated web structure with a second cutter; generating a first crack in the first side of the laminated web structure with the crack initiator; generating a second crack in the second side of the laminated web structure with the second cutter; and propagating the first crack and the second crack to intersect. The crack initiator extends from a cutter base to a height of at least 5 .mu.m. The high rake angle of the crack initiator is in the range of from about 30.degree. to about 70.degree.. The cutter base has a low rake angle that is at least about 15.degree. less than the high rake angle of the crack initiator.
A method for cutting apart a glass substrate is provided whereby scribing of the glass substrate is possible without being affected by the presence or thickness of a deposited film formed thereon and without scratching the deposited film. To treat a glass substrate having a deposited film, such as a thin film or resin film, formed on one surface thereof, there are provided a shaving device, which is a blade that removes strip-shaped portions of the deposited film to expose strip-shaped regions on the glass substrate, and a wheel cutter that forms scribed lines along the strip-shaped regions exposed on the glass substrate. The glass substrate is cut apart along the scribed lines.
