Ro Na-4-piece-HSS-Ti N-Milling-Drill-Set-3-5-6-5-8mm-RONA-829027-These-finest top quality-drill-bits-from-Ro Na-are-made-from-HSS-steel-with-a-titanium-nitride-coated-surface-giving-a-lifespan-up-to-six-times-that-of-regular-drill-bits-They-are-ideal-for-enlarging-holes-cleaning-deburring-&-rounding-off-internal-cut-outs-in-metal-wood-&-plastic-Ro Na-829027-HSS-Ti N-Milling-Drill-Set-3-5-6-5-8mm