Page 165 - Demo

163PRE-THREAD DRILLING WITH CHAMFERING Pre-Threading Recommended Hole Diameters with DCNT DrillsDrill Designation Dia. Range M ThreadHead Dia.MF Thread Head Dia.TR Thread Head Dia.M Helicoil Thread Head Dia.DCNT 068-021-12A-M8 6.5-6.99 M8 6.8DCNT 085-026-12A-M10 8.5-8.99 M10 8.5 MF10x1 8.99 TR10x1.5 8.6 MF10x1.25 8.8DCNT 102-030-16A-M12 10.0-10.99 M12 10.2MF11x1 10.0 TR12x2 10.2M10 10.5 MF12x1 10.99MF12x1.25 10.8 TR14x4 10.5 MF12x1.5 10.5DCNT 120-035-16A-M14 12.0-12.99 M14 12.0MF13x1 12.0 TR14x2 12.2M12 12.5 MF14x1 12.99MF14x1.25 12.8 TR16x4 12.3 MF14x1.5 12.5DCNT 140-039-16A-M16 14.0-14.99 M16 14.014.0MF16x1 14.99 TR18x4 14.3 M14 14.99MF16x1.5 14.5DCNT 175-042-20A-M20 17.0-17.99 M20 17.5 MF20x2 17.99 TR22x5 17.3DCNT 210-048-25A-M24 21.0-21.99 M24 21.0 MF22x1 21.0Drill Designation Dia. RangeUNF Thread Head Dia.UNC Thread Head Dia.BSW Thread Head Dia.BSF Thread Head Dia.DCNT 068-021-12A-M8 6.5-6.99DCNT 085-026-12A-M10 8.5-8.99 UNF3/8-24 8.5DCNT 102-030-16A-M12 10.0-10.99 UNC1/2-13 10.8 BSW1/2-12 10.5 BSF1/2-16 10.99DCNT 120-035-16A-M14 12.0-12.99 UNC9/16-12 12.3 BSF9/16-16 12.5DCNT 140-039-16A-M16 14.0-14.99 UNF5/8-18 14.5DCNT 175-042-20A-M20 17.0-17.99 UNF3/4-16 17.5DCNT 210-048-25A-M24 21.0-21.99Drill DesignationDia. RangeNPT Thread Head Dia.BSP Thread Head Dia.UNEF Thread Head Dia.UNJF Helicoil Thread Head Dia.DCNT 068-021-12A-M8 6.5-6.99DCNT 085-026-12A-M10 8.5-8.99 NPT1/8-27 8.5 G1/8-28 8.8 UNEF3/8-32 8.7 UNJF3/8-24 8.6DCNT 102-030-16A-M12 10.0-10.99DCNT 120-035-16A-M14 12.0-12.99DCNT 140-039-16A-M16 14.0-14.99 NPT3/8-18 14.5 UNEF5/8-24 14.8 UNJF5/8-18 14.5DCNT 175-042-20A-M20 17.0-17.99 NPT1/2-14 17.5 UNEF3/4-20 17.8DCNT 210-048-25A-M24 21.0-21.99