ATA International Product Catalogue

1575 Application Operating Condition Instructions Operating Condition Instructions The entry surface is slanted –  Level the slope through spot facing before machining The entry surface is welded –  Level it through spot facing before machining The outlet is slanted –  Reduce the feed rate by 50% at the outlet Stacked plates –  Allowed in principle –  The workpiece shall be properly clamped –  No excessive gap is allowed between the plates The entry surface is arc –  Drilling at the center at reduced feed rate is allowed –  Spot facing is required if the entry point is not at the center of the arc Cavities –  Not allowed Through hole –  Reduce the feed rate by 50% during conti- nuous cutting Step on the entry surface –  Not allowed (the entry point must be on a horizontal plane) Criteria for drill replacement Power limit Wear limit Poor surface roughness Hole diameter change Drastic increase of vibration noise P 1 P × 1.25 2 1 New drill 2 A worn drill has a power 25% higher than that of a new drill Ra D ∅ >D+0.15mm ∅ <D-0.03mm EXCHANGEABLE DRILLS 11 Index 10 9 OIL 8 7 6 5 4 3 2 1