Каталог Iscar сверла ружейные и для глубокого сверления 2022 - страница 120

GUNDRILLS USER GUIDE Drilling Tolerances Obtainable In Deep Hole Drilling Deep Drilling Tolerances Gundrill configurations when used under recommended conditions can produce holes with tolerances of IT8-IT9. When operating under optimal conditions, even better tolerances can be achieved. Nonferrous materials Aluminum Tool steel Cast iron High alloy steel>800N/mm2 Machinabilityof Metals Hardened steel Low alloy steel<800N/mm2 Carbon steel Sintered steel Drilling quality IT 13 12 11 10 9 8 7 6 5 Tolerance range under normal conditions Tolerance range under optimal conditions Surface Quality Surface quality of 0.2 Ra can be achieved when using gundrills under recommended conditions. N12 N11 N10 N9 N8 N7 N6 N5 N4 N3 N2 N1 Indexable Drills Reaming Honing Deep drilling Degree of roughness μm 50 25 12.5 6.30 3.20 1.60 0.80 0.40 0.20 0.10 0.05 0.025 (Ra roughness index) μ in 2000 1000 500 250 125 63 32 16 8 4 2 1 Tolerance range under normal conditions Tolerance range under optimal conditions Concentricity and Straightness Circularity The resulting quality depends on different factors such as: The geometric quality of bores obtained from deep • Drilling depth and diameter hole drill bits is clearly higher than that obtained • Type of machining and cutting parameters with the use of twist drills. It is possible to obtain • Quality and uniformity of the workpiece material precision with deviations of less than 4 µm. • Machine tool conditions • Gundrill support mm mm 1.0 0.05 0.84 0.04 0,66 0.03 0.5 0.02 0.33 0.01 0.16 250 500 750 mm 500 1000 mm Drilling Depth Drilling Depth Stationary workpiece – rotating tool Rotating workpiece – stationary tool 304 ISCAR