Modern Machine Shop

DEC 2016

Modern Machine Shop is focused on all aspects of metalworking technology - Providing the new product technologies; process solutions; supplier listings; business management; networking; and event information that companies need to be competitive.

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BETTER PRODUCTION Shops Using Technology 100 MMS December 2016 mmsonline.com Working in a 10-employee machine and fab- rication shop that runs 22 hours a day, five days a week, Mr. Bauer was tasked with rough-milling a high-chrome, D-2-wrought stock piece that serves as a wear part in a nail-gun mechanism. The roughly rectangular finished part measures 2.5 inches long by 1.25 inches wide and 0.350 inch thick, with a stepdown to 0.194 inch. More than half of the blank's original weight is reduced to chips in a roughing operation that includes facing and square-shoulder step milling. This operation accounts for 80 percent of total machin- ing time. Following that are drilling, slotting, and finally, radiusing to eliminate stress-raiser corners. The part is then heat treated to 60-62 HRC and oxide coated. Although Mr. Bauer was initially using inserts that were designed for high-chrome steels, he says he was lucky to get as many as five pieces o u t o f t h e m b e f o r e t h e y s h a t t e r e d . H e tried easing back the material-removal rate, b u t t h a t m a d e l i t t l e dif ference. He says it took 51 minutes to com- plete the roughing when running the par t on a Kia vx 500 CNC vertical m a c h i n i n g c e n t e r using a 2-inch-diameter, f o u r- p i t c h f a c e m i l l and settings of 625 sfm, 10 ipm and 0.050-inch depth of cut (DOC) using synthetic coolant. Under those c o ndi tio ns—o r e v e n w h e n s l o w e d down—inser ts usually popped every fourth or fif th piece. Increasing t h e D O C l e d to c h i p clogging. The process o f t e n g e n e r a t e d a p o u n d i n g s o u n d a n d created powdery chips characteristic of hard- part machining. "Catastrophic tool f a i l u r e wa s o u r m a i n problem, but we were l o o k i n g t o b o o s t throughput as well," Mr. Bauer says. T h e i m p e t u s o f change be gan with a promotional email from When the coolant becomes a Liquid Tool. Metalworking fluids to optimize productivity, economic efficiency and machining quality. Our specialists support you to get the best out of your machines and tools with the Liquid Tool. Please contact us for your local distributor. Blaser Swisslube Inc. Goshen, New York Phone 845-294-3200 mailboxusa@blaser.com www.blaser.com

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