Saving a bit more money

When you’re doing 13 million drilling operations on four million holes in 300,000 auto parts a year in a 24-hour, six-day-per-week operation, keeping the necessary solid carbide drills available can put you on a very unamusing merry-go-round.

Given the three-to-four week turnaround times for reconditioning, you’ll need to own, and circulate, more than 600 drills in order to sustain a robust, uninterrupted operation.

Global Gear and Machining (GGM) of Downers Grove, Ill., decided to hop off this ride. They switched instead to alloy steel drills with replaceable coated-carbide points for drilling automotive drive-train flanges.

The move, essentially a drop-in replacement, reduced tool inventory from 600 pieces to just 20 drill bodies and a supply of replaceable points, saving about $205,000 a year.

The drills are Ingersoll cutting tools’ Quik-Twist drills, which feature a 20-second point change with no retaining screws or threaded hardware to fiddle with.

Tooling inventory cost dropped from about $38,000 to less than $4,000 and throughput rose about 40 percent. More important, the company eliminated about $138,000 a year in drill recoating and regrinding, shipping, scrap and unscheduled outage cost due to prematurely broken drills – while meeting all production schedules.

Looking for answers
GGM’s process engineering group put their finger on the problem.

“With a four-week reconditioning cycle, the operation requires 16 drills per shift, each costing about $60,” said process engineer Enrique Saldaña. “Do the math for this two-shift, six-day-a-week operation with one tool change per shift, and suddenly we’re owning and shuttling 600 drills.”

Contributing to the 600-unit figure were experience-based provisions for premature tool failure – especially on the reconditioned drills. Such failures averaged one per shift.

So they brought the problem to Ingersoll drilling product manager Bob Jennings and its Chicago distributor, who suggested the Quik-Twist remedy. Ingersoll provides both solid carbide and Quik-Twist drills.

“Solid carbide has its place,” said Jennings. ”But, in a high-volume operation like this, the replaceable-point drill is the better answer. It eliminates all that inventory, uncertainty and trafficking associated with reconditioning.  As with indexable-tool milling and turning, you use the inexpensive carbide point once, then discard it, and re-use the body. You’re off the reconditioning merry-go-round for good.”

Tests validate idea
Ingersoll ran comparative tests to validate the idea before GGM made the switch permanent. On average, penetration rates ran 40 percent higher than before. On that basis, Ingersoll projected a $125,000 hard annual dollar saving simply from eliminated inventory and reconditioning costs. 

So the GGM process engineering group put the new tools into practice. No other process or tooling changes were needed.

Unexpected dividend
GGM runs the parts at Jennings’ recommended machining rates and maintains the same changeout schedule as before.  Operators swap out the drills and change points off line, conserving uptime. The self-clamping points take only 20 seconds to change.

After the tooling switch, Global noticed two unexpected benefits that simply compounded their savings. First, unscheduled mid-shift drill failures disappeared. Second, due largely to the higher penetration rates and fewer unscheduled stoppages, throughput increased about 5 percent. These saved another $38,000 per year.

For further information, contact Ingersoll Cutting Tools, 845 S. Lyford Road, Rockford, IL . Phone , fax . Email , www.ingersoll-imc.com.

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