Case Studies

Reducing Production Costs for Machining Inconel Gear Housings

Posted on: November 1, 2018
Tags: Precision Machining, Aerospace, BSF, Spotfacing, Inconel, Back Counterboring

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A precision manufacturer focused on the aerospace Industry was using a competitor’s back spotfacing tool for a gear housing, as the Heule BSF had not been introduced at the time his project began. Due to his lack of success with the competitor’s tool (tool breakage as well as insert longevity) the customer was willing to test the HEULE BSF not long after its introduction.

Application details

Main bore: Ø.278”
Spotface diameter: Ø.535” Plus/Minus .008
Material: Inco718
Machine: Cat 40 VMC Mori Seiki: 1000Psi through-spindle

back spotfacing tool


HEULE recommended the BSF-A-0700/040-7.5 using carbide TiAlN-coated blade BSF-M-A-1A-6.0 to obtain a .531 back spotface.

Machining parameters:
Speed: 55 SFM / 395 RPM
Feed: F=.0006” per revolution / .25 IPM
Coolant: Internal coolant


The HEULE BSF was able to complete 1 part per blade (10 holes) while the competitor’s tool used 5 blades per part. In-cut cycle time (time to index inserts on competitor not included) went from 62 minutes to 7 minutes 45 seconds. Estimated savings $130,000 amortized over 300 parts per year.