REPLACEABLE POINT DRILLS DRILL POINT REPLACEMENT INDICATIONS  1. Limit cutting edge wear to .008” to .012”. Fig. 1: Wear Limit Fig. 2: Power Restriction (see Fig. 1) 2. Power consumption exceeds 125% of normal. (1) (2) (see Fig. 2) P Px1.25 3. Drilled hole diameter variation. (see Fig. 3) 4. Deterioration of surface finish of the drilled hole. (see Fig. 4) Spindle loadmeter 5. Significant increase in noise or vibration. (see Fig. 5) .008"-.012" (1) New Drill Point(2) Worn Out Drill Point Fig. 3: Diameter Change Fig. 4: Surface Finish Decline Fig. 5: Noise or vibration drastically increases RECOMMENDED COOLANT PRESSURE AND FLOW RATE For proper chip evacuation, the coolant must flow through the tool. If the machine is not equipped with coolant through the spindle, we recom- mend using a coolant inducer. External coolant supply can be used if the hole depth is less than 1xD and reduced cutting parameters are applied. Coolant Mix Recommended coolant concentration is 6% to 8%. When drilling stainless and high strength steels, a 10% concentration is recommended. Dry Drilling It is possible to drill without coolant in cast iron. oil mist through the drill is required (2xD max hole depth). 678