Case Study

Aerospace Case Study 08 / 15

Engine Casing Machining Case Study

An engine casing is the primary structural shell of an aircraft engine.

engine casing machining case studyaerospace cnc machining5 axis aerospace machining

Case Overview

Core project data for this machining case.

Industry Aerospace

Product Engine Casing

Material Aluminum 7075 / Ti-6Al-4V / Inconel 718

Process Forging + Heat Treatment + CNC Machining

Machine Model HYR VMC1165 / HYR 5 Axis Machining Center

Tolerance +/-0.005 mm

Surface Finish Ra0.4

Application Aircraft Engines / Turbofan Engines / Gas Turbines

Problem

Machining problem to solve

Unlike turbine blades or impellers, casings are:Large+Thin Wall+High Precision+Thermally SensitiveTraditional machining:Multiple SetupsRepositioningAccumulated ErrorsModern aerospace machining:5 Axis CNCSingle SetupComplete Machining

Solution

HYR-CNC machining plan

The customer manufactures:Turbofan engine casingsUAV engine housingsGas turbine casingsAerospace ring structuresMaterials:

Machine Used

Recommended machine configuration

Machine: HYR CNC machining center selected according to aerospace material, part size and tolerance

Process: Rough machining, semi-finishing, 5-axis finishing and inspection based on the document content

Accuracy Control: Rigid fixturing, thermal stability, deformation control and CMM inspection

Cost Method: Published with existing website assets first to keep implementation cost low

Process

Timeline from raw material to inspection.

01 Material preparation

02 Rough machining

03 Semi-finishing

04 5-axis finishing

05 Inspection

Full Case Article

Machining background, difficulty and solution logic.

Quick Facts

Item

Details

Industry Aerospace Product Engine Casing Materials Aluminum 7075 / Ti-6Al-4V / Inconel 718 Manufacturing Process Forging + Heat Treatment + CNC Machining Machine HYR VMC1165 / HYR 5 Axis Machining Center Tolerance +/-0.005 mm Diameter 300-2500 mm Surface Finish Ra0.4 Application Aircraft Engines / Turbofan Engines / Gas Turbines

Introduction

An engine casing is the primary structural shell of an aircraft engine.

Its function is not simply to cover internal components.

It must: Support rotating assemblies Maintain concentricity Withstand vibration Resist thermal deformation Contain high-speed rotating parts Provide mounting interfaces The casing serves as: Engine BackboneStructural SupportSafety ProtectionPrecision Alignment Without a precisely machined casing: Rotor MisalignmentExcessive VibrationReduced EfficiencyPotential Failure

What Is An Engine Casing?

Each section contains precision interfaces that must align perfectly.

An aerospace engine casing is a large ring-shaped structure that houses: Compressor stages Bearings Shaft systems Turbine assemblies Sealing systems Typical structure: Front CasingCompressor CasingCombustor CasingTurbine CasingExhaust Section

Customer Background

HYR CNC developed a dedicated engine casing machining solution.

The customer manufactures: Turbofan engine casings UAV engine housings Gas turbine casings Aerospace ring structures Materials: 7075 AluminumTi-6Al-4VInconel 718 Primary challenges: Large diameter machining Circularity control Thin wall distortion Deep bore machining Assembly interface accuracy

Why Engine Casings Are Difficult To Machine

Unlike turbine blades or impellers, casings are: Large+Thin Wall+High Precision+Thermally Sensitive

Challenge 1

Large Diameter Structures Typical diameter: 300 mm1000 mm2500 mm Problems: Thermal expansion Roundness control Fixture stability

Challenge 2

Concentricity becomes a critical inspection item.

Concentricity Requirements Engine components rotate at: 10,000 RPM30,000 RPM Even tiny errors may create: MisalignmentVibrationBearing Wear Therefore:

Challenge 3

Thin Wall Deformation Typical wall thickness: 2 mm10 mm Challenges: Deflection Vibration Chatter Distortion after unclamping

Challenge 4

Tool accessibility becomes difficult.

Deep Internal Features Casings contain: Bearing bores Seal grooves Mounting faces Cooling passages Typical structure: Large RingDeep BoreThin WallPrecision Features

Aluminum 7075

Applications: UAV engines Lightweight compressor housings Advantages: High StrengthLight WeightExcellent Machinability

Ti-6Al-4V

Applications: Military aircraft engines High-performance engine structures Advantages: High StrengthCorrosion ResistanceWeight Reduction

Inconel 718

Applications: Turbine casings Hot section structures Advantages: Heat ResistanceOxidation ResistanceHigh Temperature Strength Challenges: High Cutting ForceRapid Tool Wear

Why 5-Axis Machining Is Necessary

Traditional machining: Multiple SetupsRepositioningAccumulated Errors Modern aerospace machining: 5 Axis CNCSingle SetupComplete Machining Benefits: Better concentricity Higher geometric accuracy Reduced cycle time Improved consistency

HYR VMC1165

Suitable for: Medium-sized casings Aluminum housings Structural aerospace components Travel: 1100 × 650 × 650 mm Advantages: High rigidity Excellent heavy cutting performance Stable dimensional control

HYR 5 Axis Machining Center

Suitable for: Titanium CasingsInconel CasingsComplex Ring Structures Advantages: Full-feature machining Improved accessibility Better surface quality

Step 1

Forging Preparation Produce: Near-net ring structures Optimized grain flow

Step 2

Heat Treatment Improve: Strength Stability Fatigue performance

Step 3

Rough Machining Remove: 60%80%Material Machine: External diameters Internal bores Mounting surfaces

Step 4

Stress Relief Reduce: Residual StressPart Distortion

Step 5

Semi-Finishing Machine: Bearing seats Seal grooves Internal cavities

Step 6

Finish Machining Requirements: Tolerance+/-0.005 mmSurface FinishRa0.4 Machine: Critical interfaces Precision bores Sealing surfaces

Step 7

Deburring Remove: Burrs Sharp edges Loose particles

Step 8

Inspection Verify: Concentricity Circularity Surface quality Dimensional accuracy

Circularity Inspection

Requirement: ≤0.01 mm Inspect: Roundness Cylindricity

Concentricity Inspection

Requirement: ≤0.01 mm Inspect: Bearing bores Rotor interfaces

Surface Finish Inspection

Requirement: Ra0.4 Inspect: Sealing surfaces Mounting faces

CMM Inspection

Verify: Bore positions Hole patterns Geometric dimensions

Results

Item

After implementing HYR machining solutions: Before After Concentricity 0.03 mm 0.01 mm Surface Finish Ra0.8 Ra0.4 Cycle Time 100% -25% Scrap Rate 1.6% 0.15% Assembly Accuracy Baseline +30% Customer benefits: Better assembly consistency Reduced vibration Improved engine performance Lower manufacturing costs

HYR VMC1060

Recommended for: Small aerospace housings UAV engine structures

HYR VMC1165

Recommended for: Medium engine casings Structural ring components

HYR 5 Axis Machining Center

Recommended for: Titanium casings Inconel housings Aerospace engine systems

What Is 5 Axis CNC Machining?

Turbine Blade Machining Case Study Compressor Impeller Machining Case Study Blisk Machining Case Study Turbine Disk Machining Case Study Titanium Machining Guide

What is an engine casing?

An engine casing is the structural housing that supports and protects critical engine components while maintaining alignment and rigidity.

Why are engine casings difficult to machine?

Because they combine: Large diameters Thin walls Tight concentricity requirements Complex internal features

What materials are commonly used?

7075 aluminum, Ti-6Al-4V titanium and Inconel 718 are widely used.

Why is concentricity important?

Poor concentricity causes vibration, bearing wear and reduced engine performance.

What tolerance is typically required?

or better.

Most aerospace engine casings require: +/-0.005 mm

Conclusion

Engine casings are among the most important structural components in aerospace propulsion systems.

Their large dimensions, tight geometric tolerances and demanding operating environments require advanced CNC machining technologies.

With excellent large-part machining capability, stable dimensional control and aerospace-grade manufacturing solutions, HYR CNC provides reliable and efficient engine casing machining solutions for global aerospace manufacturers.

Result

Before and after machining improvement.

Item	Before	After
Result 1	Before optimization	After implementing HYR machining solutions:
Result 2	Before optimization	Concentricity
Result 3	Before optimization	0.03 mm

FAQ

Common buyer questions for this case.

What is this aerospace article about?

This page covers engine casing requirements, machining difficulty, process planning and machine selection.

Which machines are recommended?

HYR VMC, HMC and 5-axis machining centers are selected according to material, size, tolerance and contour complexity.

Can HYR-CNC support similar aerospace parts?

Yes. Send drawings, material, tolerance and production volume for a suitable machining proposal.

Need a similar CNC machining solution?

Send your drawing, material, tolerance, surface finish and production volume. HYR-CNC will recommend the right machine configuration and machining proposal.

Start Machine Selection

Engine Casing Machining Case Study

Core project data for this machining case.

Machining problem to solve

HYR-CNC machining plan

Recommended machine configuration

Timeline from raw material to inspection.

Machining background, difficulty and solution logic.

Quick Facts

Introduction

What Is An Engine Casing?

Customer Background

Why Engine Casings Are Difficult To Machine

Challenge 1

Challenge 2

Challenge 3

Challenge 4

Aluminum 7075

Ti-6Al-4V

Inconel 718

Why 5-Axis Machining Is Necessary

HYR VMC1165

HYR 5 Axis Machining Center

Step 1

Step 2

Step 3

Step 4

Step 5

Step 6

Step 7

Step 8

Circularity Inspection

Concentricity Inspection

Surface Finish Inspection

CMM Inspection

Results

HYR VMC1060

HYR VMC1165

HYR 5 Axis Machining Center

Related Articles

What is an engine casing?

Why are engine casings difficult to machine?

What materials are commonly used?

Why is concentricity important?

What tolerance is typically required?

Conclusion

Before and after machining improvement.

Common buyer questions for this case.

What is this aerospace article about?

Which machines are recommended?

Can HYR-CNC support similar aerospace parts?

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