The work gear should be shaved from the same locating 44 Gear Technology OVERLAP CROSS!ED-· AXES . Plunge shaving points or surfaces used in the preshaving operation. Locating faces should be clean, parallel and square with the gear hole. Gears with splined holes may be located from the major dia- meter, side of the splined teeth or minor diameter. When shaved from the centers, the true center angle should be qualified and surfaces should be free of nicks, scale and burrs. Locating points on the work arbors and fixtures should be held within a tolerance or 0.0002 in. The arbor should fit the gear hone snugly. Head and tails tack centers should run within 0.0002 in. For the most dependable results, gears should be shaved from their own centers whenever possible. If this is not possi- ble, rigid, hardened and ground arbors , having large safety centers would be used. Locating faces should be the same as those used in habbing or shaper cutting. Integral tooling is another method which is becoming popular, especially in high production shops. This consists of hardened and ground plugs instead of centers, on the head and tailstocks. These plugs are easily detached and replaced when necessary. They locate in the bore and against the faces of the work gear.