A grinding apparatus including a chuck table for holding a wafer, a grinding unit having a spindle for rotating a grinding wheel, an inclination adjusting unit for adjusting the inclination of the rotation axis of the chuck table with respect to the rotation axis of the spindle, a touch panel, and a control portion. The control portion is adapted to compare the information regarding the target sectional shape input into a target shape input field with the information regarding the present sectional shape input into a present shape input field and then control the inclination adjusting unit to change the inclination of the rotation axis of the chuck table so that the wafer is ground to obtain the target sectional shape of the wafer.

A grinding apparatus including a chuck table for holding a wafer, a grinding unit having a spindle for rotating a grinding wheel, an inclination adjusting unit for adjusting the inclination of the rotation axis of the chuck table with respect to the rotation axis of the spindle, a touch panel, and a control portion. The control portion is adapted to compare the information regarding the target sectional shape input into a target shape input field with the information regarding the present sectional shape input into a present shape input field and then control the inclination adjusting unit to change the inclination of the rotation axis of the chuck table so that the wafer is ground to obtain the target sectional shape of the wafer.

In a step of performing cylindrical grinding of a polycrystalline silicon bar 10 grown by a Siemens method, this cylindrical grinding step is performed such that a polycrystalline silicon rod 30, whose center axis C.sub.R is shifted from a center axis C.sub.0 of a silicon core wire 20 by 2 mm or more, is manufactured.

A crystal centering and clamping device has a first jig, a second jig, a clamping mechanism and an ejector mechanism. The first jig and the second jig are used for bonding on opposite end faces of a crystal, and positioning holes are arranged at the central positions of the first jig and the second jig. The ejector mechanism is located at one side of the clamping mechanism and can move towards or away from the clamping mechanism, so that the ejector mechanism can abut against the positioning hole of the first jig or the second jig above the crystal in the clamping mechanism.

A grinding apparatus including a chuck table for holding a wafer, a grinding unit having a spindle for rotating a grinding wheel, an inclination adjusting unit for adjusting the inclination of the rotation axis of the chuck table with respect to the rotation axis of the spindle, a touch panel, and a control portion. The control portion is adapted to compare the information regarding the target sectional shape input into a target shape input field with the information regarding the present sectional shape input into a present shape input field and then control the inclination adjusting unit to change the inclination of the rotation axis of the chuck table so that the wafer is ground to obtain the target sectional shape of the wafer.

A grinding apparatus including a chuck table for holding a wafer, a grinding unit having a spindle for rotating a grinding wheel, an inclination adjusting unit for adjusting the inclination of the rotation axis of the chuck table with respect to the rotation axis of the spindle, a touch panel, and a control portion. The control portion is adapted to compare the information regarding the target sectional shape input into a target shape input field with the information regarding the present sectional shape input into a present shape input field and then control the inclination adjusting unit to change the inclination of the rotation axis of the chuck table so that the wafer is ground to obtain the target sectional shape of the wafer.

A variable radius sanding block for sanding curved surfaces. The variable radius sanding block includes a base member and a plurality of variably sized radius patches. The base member is sized and proportioned to allow radius patches of varying size to be inserted, such that each of the radius patches will change the curvature of the sanding block upon insertion. The base member also having a folded flexible internal structure and a pair of flexible arms that facilitate insertion of radius patches of varying size. The radius patch includes a pair of grooves that receive the flexible arms of the base member and secure the base member to the radius patch.

A variable radius sanding block for sanding curved surfaces. The variable radius sanding block includes a base member and a plurality of variably sized radius patches. The base member is sized and proportioned to allow radius patches of varying size to be inserted, such that each of the radius patches will change the curvature of the sanding block upon insertion. The base member also having a folded flexible internal structure and a pair of flexible arms that facilitate insertion of radius patches of varying size. The radius patch includes a pair of grooves that receive the flexible arms of the base member and secure the base member to the radius patch.

In a step of performing cylindrical grinding of a polycrystalline silicon bar 10 grown by a Siemens method, this cylindrical grinding step is performed such that a polycrystalline silicon rod 30, whose center axis C.sub.R is shifted from a center axis C.sub.0 of a silicon core wire 20 by 2 mm or more, is manufactured.

A sculptured drum for a retread process that has an inner radial section with a central axis that extends in an axial direction. The sculptured drum has a plurality of support members that extend outward from a drum outer surface in a radial direction and that are located outward from the inner radial section in the radial direction. A tread that has a plurality of grooves is supported by the sculptured drum during a brushing process and pass across the sculptured drum such that some but not all of the grooves have one of the support members disposed therein. The support members when disposed within the grooves do not completely fill the grooves, and when disposed within the grooves engage a lower surface of the tread.