The customer is a tier 2 supplier of gears and gear assemblies. The part being manufactured is a transmission gear carrier for the Hummer H3. The customer was drilling a 14 mm (.551″) bolt pattern requiring true position. The holes were being drilled into a composite consisting of two powder metal steel components that were joined by sinter-brazing.
The customer was drilling with a competitive special solitude carbide TiN coated twist drill. The tool was run at 1600 RPM and .010 IPR and was holding true position requirements.
AMEC suggested using a GEN2 T-A® Drill Insert C-2 carbide with AM200® coating (Item # 4C20H-14). AMEC also suggested a special holder: a #0 T-A® Chrome Helix holder with a 4.375″ straight flute and 0.79″ drill depth. The recommended speeds and feeds for the tooling were 830 RPM and .007 IPR. The tooling had to at minimum match the 16 IPM that the competition was getting. They started at 830 RPM, .0035 IPR for the first .156″ to start the hole then went to .007 IPR (2.90 IPM to 5.80 IPM). They ended up running at 1600 RPM, .005 IPR for the first .156″ depth. We then went to .010 IPR to finish the hole (8.00 IPM to 16.00 IPM). The savings were $82.03, a savings of 38.29%.
At the present time they are expected to produce 50,000 carrier assemblies. Over $13,650 were saved in 50,000 pieces.