VIDEO: 60sec Troubleshooting – Drilling: Chip Shape vs. Coolant Type

Welcome to OSG's 60 second troubleshooting video. Drilling usually incorporates some form of coolant and/or chip evacuation method. The most commonly seen methods are external flood coolant, usually from a side nozzle or nozzles or sometimes through slits in the collet, through the tool coolant where air or lubricant exits from the tip of the tool, minimum quantity lubricant or MQL for short, which is a finely aerated oil that is shot out of the tip of the drill and lastly, in a dry air blow from a side nozzle or through the collet. We will look at the effect of coolant method on chip shape using 1045 carbon steel material, a standard 10 millimeter drill, and attempting 5 holes each at 200 sfm and 15 inches per minute.

In the case of flood coolant, the chips maintained a silver color with some discoloration on the bottom half of the chips. The chip shape is mostly short in length and has good curl amount with a few chips having some longer tails.

In the case of water soluble through tool coolant, the chips are completely silver with no darkened discolorations. This tells us that the chips are the coolest and hence the cutting edges of the drill aren't as hot. This translates to longer overall tool life. The chip shape is mostly short length and well curled with a few chips having some longer tails. In comparison, the coolant through chips here are curled a bit tighter than the flood coolant chips which is necessary for high pressure chip evacuation.

In the case of MQL, the chips are extremely dark blue and black, the darkest of all the chips collected. This tells us that the operation runs very hot and tool life will likely be diminished. The chip shape is also the shortest in length and the tightest curled of all the chip types, which makes these chips the least likely to chip pack and cause tool breakage problems. In the case of dry air blow coolant, the chip color is mostly dark blue with a bit of dark brown edging. The chip shape is mostly small and curled but the curl tightness amount is less uniform in this case than the rest of the chips collected. This could cause troubles with chip evacuation. Thank you for watching. For more information please visit www.osgtool.com.