Hard CNC Milling · AerMet 100 Alloy Steel
AerMet 100 Hard Machining: 6-Up Fixturing and a 20-Part Cutter Interval
A 1,800-part AerMet 100 order moved from a one-part FANUC finish-milling setup to six-part fixturing on a Brother machining center. After the initial cutter chipped at about one part, an Ø8 HARVI I TE KCPM15 end mill was changed at about 20 parts to protect precision-size stability. The published CMM screen records one randomly selected finished part, not a batch capability result.
At a Glance
- Material
- AerMet 100 alloy steel
- Process
- Post-heat-treatment finish milling; one-part FANUC setup changed to six-part Brother fixturing
- Production volume
- 1,800 completed parts
- Drawing hardness requirement
- 51–54 HRC after heat treatment; no measured hardness value is published
- Revised end mill
- Ø8 Kennametal HARVI I TE, four-flute solid carbide, KCPM15 grade
- Observed tool-change interval
- Initial cutter: about 1 part; revised cutter: about 20 parts before planned replacement
- Downstream sequence
- Fine steel-bead blasting (shop designation 180#), laser marking, then sampled CMM inspection
- Published inspection scope
- One randomly selected finished part; three mapped characteristics published from a 12-characteristic front-side CALYPSO report, with all 12 reported inside their displayed limits
From the Production Drawing
The Requirement, in the Engineer's Own Notes
The published excerpt retains the boxed Ø10 g6 callout with its ⌀0.01 cylindricity refinement and ⌀0.06 position tolerance to datums C | D. The title and revision tables, part and drawing identifiers, customer-identifying content, personnel names, laser-marking code specification and every unrelated dimension have been removed from the image pixels so only the requirement discussed on this page remains.
01
The Challenge
The production risk came from the full route rather than from one cut in isolation. The 1,800-part order combined rough machining, heat treatment to a drawing-specified 51–54 HRC condition, precision finish milling in the hardened state, appearance finishing, laser marking and dimensional inspection. In the original one-part finish-milling setup on a FANUC ROBODRILL, the initial cutter developed visible edge chipping and was usable for only about one component. Continuing with a degraded edge affected the stability of precision dimensions. Moving to a six-part fixture load also meant that the revised tool and replacement rule had to stay controlled across multiple components before the fixture was unloaded.
02
OUJI's Approach
OUJI changed both the cutting tool and the finish-milling setup. The critical operation moved to an Ø8 Kennametal HARVI I TE four-flute solid-carbide end mill in KCPM15 grade, while the workholding moved from one component on the FANUC to six components per fixture load on a Brother machining center. The revised cutter was changed at about 20 completed parts because extending use beyond the controlled interval affected precision-size stability; it was not run until catastrophic failure. After finish machining, the parts received fine steel-bead blasting using the shop’s 180# designation for a visually consistent appearance. No separate roughness requirement was specified for that blast finish. Laser marking followed, with the marking content excluded from publication, and final quality control used sampling inspection.
03
The Result
All 1,800 components were completed through the stated route. The revised fixture held six parts per load instead of one, and the observed count between cutter changes moved from about one part to about 20. Because the machine, fixture and cutter changed together, this is reported as the result of the revised process, not as a controlled cutter-only comparison. OUJI did not calculate a cycle-time, daily-output or total-capacity increase, so the case makes no sixfold productivity or other output claim. To check dimensional stability in the finished condition, one component was randomly selected from the completed parts for the photographed front-side ZEISS CALYPSO program. Its report contains 12 characteristics, all inside their displayed tolerance limits. Three rows map to the boxed Ø10 g6 callout in the released drawing excerpt. Diameter measured 9.9867 mm against the 9.9860–9.9940 mm limits programmed in the CMM routine (−0.0060 / −0.0140 mm deviations from the 10.0000 mm nominal). Its −0.0133 mm deviation places it 0.7 µm above the programmed lower limit: inside tolerance, but near the bottom of that band. Cylindricity measured 0.0027 mm against a 0.0100 mm maximum. Position to datums C | D measured 0.0127 mm against a 0.0600 mm maximum. Those three published readings are a subset of the 12-characteristic report. This evidence supports only that sampled part, mapped Ø10 feature and front-side program; it does not prove batch-wide acceptance, every drawing dimension, Cpk, yield or zero defects across the other 1,799 parts.
Production Sequence
From One-Part Hard Finishing to 6-Up Fixturing and a Sampled CMM Check
The photographed sequence shows where the original cutting strategy became a dimensional risk, which variables changed in the finish-milling cell, and exactly what the published inspection result can support.
“6-up” means six parts were clamped in one fixture load; it does not establish a sixfold output increase. “About 20 parts per cutter” is OUJI’s observed planned replacement interval for this operation, not a Kennametal guarantee or a cut-to-failure value. The 51–54 HRC value is a drawing requirement, not a published hardness measurement.
01 · Initial finish setup
Start with one part per FANUC fixture load
The original post-heat-treatment finish-milling setup held one component on a FANUC ROBODRILL. The photograph documents the production setup, not the exact instant of cutting. At this stage, tool-edge condition was directly tied to the stability of the precision finishing operation.
02 · Tool-edge risk
Stop when the initial cutter shows visible chipping
The initial cutter developed clear edge chipping and required replacement after about one component. OUJI treated that wear as a process-control problem because continuing without a tool change affected precision-size stability.
03 · Tooling revision
Change to an Ø8 HARVI I TE KCPM15 end mill
The revised critical operation used an Ø8 Kennametal HARVI I TE four-flute solid-carbide end mill in KCPM15 grade. Naming the actual tool makes the project traceable without claiming that the product was designed specifically for AerMet 100 or that the observed interval transfers to another toolpath, machine or material condition.
04 · Fixture revision
Move finish milling to six parts per Brother fixture load
The Brother machining-center setup located and clamped six components at once instead of one. Since the machine, workholding and cutter changed together, the case reports the combined process revision and does not assign a standalone productivity multiplier to any one change.
05 · Controlled tool life and finish
Change the cutter at about 20 parts, then complete the surface sequence
The revised cutter completed about 20 components before planned replacement. It was changed at that observed point because longer use affected precision dimensions. After finish machining, the parts received 180# fine steel-bead blasting for visual consistency and then laser marking. No blast-finish roughness requirement was specified, and the actual marking content is excluded from publication.
06 · Sampled CMM inspection
Randomly select one finished part for CMM probing
Final quality control used sampling inspection. To document the finished-condition check shown here, OUJI randomly selected one completed component and ran its front-side program on a ZEISS coordinate measuring machine using CALYPSO.
07 · Published result
Publish three mapped readings from a 12-characteristic report
The permanently cropped CALYPSO screen reports 12 characteristics in the front-side program, all inside their displayed tolerance limits. Diameter, cylindricity and position for the boxed Ø10 g6 feature are the three report rows mapped to the released drawing excerpt and published on this page. The evidence applies only to the randomly sampled finished part and that program; it is not a full-batch, all-dimension or statistical-capability result.
Sources & technical references
- AerMet 100 alloy — Carpenter Technology
Manufacturer reference for the high-hardness, high-strength AerMet 100 alloy family. The project-specific 51–54 HRC value is a drawing requirement, not a value inferred from this page or a published hardness-test result.
- FANUC ROBODRILL compact machining center — FANUC Corporation
Manufacturer reference for the ROBODRILL machine family. The exact machine model is not claimed; the one-part project setup comes from OUJI production records and photographs.
- Brother SPEEDIO compact machining centers — Brother Industries, Ltd.
Manufacturer reference for the Brother SPEEDIO machine family. The six-part workholding is an OUJI project-specific fixture, not a standard machine specification.
- Kennametal HARVI portfolio selection guide — Kennametal Inc.
Manufacturer reference for the four-flute HARVI I TE solid-carbide end-mill family and KCPM15 grade. The Ø8 selection and approximately 20-part change interval come from this project; the guide is not presented as an AerMet 100-specific guarantee.
- ZEISS CALYPSO measuring software — Carl Zeiss Industrial Metrology
Manufacturer reference for the CMM software visible in the inspection evidence. The 12-characteristic report and three mapped readings come from the redacted project screen and apply only to the published single-part inspection scope.
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