Drill Selection Guide Description Drilling Depth (L/D) Coating Coolant Carbon Steel, Tempered Steel Hardened Steel Stainless Steel Ti Alloy Heat-resistant Steels Cast Iron Ductile Cast Iron Aluminum Alloy Copper Alloy Composite Ref. Page Supply Alloy Steel Up to 35HRC C C SKD Up to From Up to SUS Ti Inconel FC FCD Al Cu CFRP 0.29% SKS 45 HRC 46 HRC 0.28% GS Type External S G G S S S S S J8 HGS Type Internal G G G S G G S S S S J8 HY Type Internal G G G G J28 External G G G S S S S S MDF Type External G G G S S S S S J34 Internal G G G S S S S S XHGS Type Internal S G G S S S S J48 PHT Type Internal S G G S S S S J48 WGS Type External S G G S S S S S J44 HX Type Internal G G J20 NHGS Type Internal S S G G J56 DAL Type - External G S J62 J DDL Type - External G S J62 Drilling D Type External G G S J30 Solid SGS Type External S G J46 Special SDC Type Indexable Dry S G J61 Reamer Brazed MLDH Type Internal G G S S G G G S J63 Others MLDH-P Type Internal G G S S G G G S J63 MDSS Type External G G G G S G S G G S J66 MDUS Type External G G G S G J66 MDUP Type External G G G S G J66 J3