Page 248 - Demo

246 ISCAR DEEP HOLE DRILLINGTable 6.11.1.2 %u2013 Drilling Head ProfileStandard Gundrill Head Profiles Drilling capacity and finish of the drilled hole are dependent on the geometrical shape of the drill head. Both the profile and the sharpening must be matched to the workpiece material.The profile is defined when the tool is manufactured. Although regrinding may change the cutting geometry, the profile should remain the same.General Sketch Profile DLa%u00d8D%u03b1PAll cross section profile parameters such as: P, La and %u2018a%u2019 must be precisely matched to the workpiece material properties.Suitable for cast iron only. Very effective in grey cast iron (usually coated).Profile G (Universal) Profile EStandard form for most material types, particularly for materials with a tendency to shrink. Recommended for high precision bore tolerance and straightness. Maintains precise exit hole size. Recommended when extra burnishing is required.General use, for alloys and stainless steel. This profile eliminates the problem of the tool sticking in the hole after the outer corner dulls. Especially suitable for crankshaft and other forged materials. Recommended for accurate hole straightness.Profile A Profile HSuitable for cast iron (usually coated) and aluminum alloys. Can be used for cross drilling, angular entry or exit and for interrupted cut. Large coolant gaps between pads.Recommended for all nonferrous and cast iron materials up 5 mm diameter. Sometimes used for wood and plastic with larger back taper.Profile B Profile IExcellent size control, for high precision hole tolerance. Used for cast iron and aluminum alloys.Used for aluminum and brass for best hole finish. For intersecting holes and interrupted cut or when extra outer diameter support and burnishing is required.Profile CUsed for angled entry or exit. Large back taper, for shrinking materials such as high temperature and titanium alloys and stainless steel. Large coolant gaps between pads.