U.S. Aerospace Manufacturer × Honscn Precision CNC & EDM Nickel 718 Twelve-Point Flange Bolts with Dedicated Heat Treatment

Product Introduction: Nickel 718 Twelve-Point Flange Bolt

• Material: Nickel Alloy 718 (Inconel 718)

• Type: 12-point flange bolt

• Industry: Aerospace

• Key Requirements:

  • High tensile strength

  • Controlled hardness

  • Excellent fatigue resistance

  • Dimensional accuracy

This bolt is used in structural and high-load aerospace assemblies, where failure is not an option. Even minor deviations in hardness, tensile strength, or microstructure can lead to premature failure of the threaded shank.

Manufacturing Challenges

1. Complex Bolt Head Geometry

The twelve-point bolt head required extremely sharp internal profiles and consistent geometry.

Conventional machining alone could not achieve the required precision without tool wear or deformation. To meet the design intent, we applied Electrical Discharge Machining (EDM) specifically for the bolt head, ensuring:

• Clean and accurate point geometry

• No mechanical cutting stress

• Excellent repeatability

2. Strict Mechanical Property Requirements

The customer specified that after heat treatment, the bolt must achieve:

• Hardness: 42 HRC

• Tensile Strength: 220 KSI

In Nickel 718 fasteners, these values are critical. If hardness or tensile strength falls outside the target range, the threaded section becomes prone to failure, especially under cyclic loads.

3. Dedicated Heat Treatment — No Mixed Batches

Unlike standard fasteners, this product could not be heat-treated together with other parts.

To guarantee consistency, the customer required:

• A dedicated furnace cycle

• No mixed materials or part types

• Full control over temperature, soak time, and cooling

This significantly increased processing complexity but was essential to prevent uneven strengthening or microstructural inconsistency.

Our Manufacturing Solution

Precision CNC Machining + EDM Processing

• The bolt body and threaded shank were produced using high-precision CNC machining, optimized for Nickel 718’s toughness and work-hardening behavior.

• The twelve-point flange head was formed using EDM, ensuring precise geometry without inducing mechanical stress or distortion.

This combination allowed us to maintain tight tolerances while preserving material integrity.

Individual Furnace Heat Treatment

To meet the mechanical requirements, we implemented a dedicated heat treatment process exclusively for this product:

• One furnace cycle per batch

• Controlled aging and strengthening parameters

• No co-processing with standard fasteners

After heat treatment, all parts were tested and achieved:

• 42 HRC hardness

• 220 KSI tensile strength

Most importantly, the threaded shank maintained structural integrity, eliminating the risk of premature breakage.

Quality Verification & Testing

Each production batch underwent:

• Hardness testing

• Tensile strength verification

• Visual and dimensional inspection

This ensured every bolt met aerospace-grade performance standards before shipment.

Project Results

By applying the correct combination of CNC machining, EDM processing, and dedicated heat treatment, we delivered a solution that met all technical and performance requirements.

Key Outcomes:

• Stable and repeatable mechanical properties

• No thread cracking or premature failure

• Full compliance with customer specifications

• Increased confidence for critical aerospace applications

The customer approved the parts for continued production and recognized the value of a process-driven, detail-focused manufacturing approach.

Why Aerospace Customers Choose Honscn

This project reflects our core strengths in aerospace manufacturing:

• Deep understanding of high-performance alloys

• Willingness to run dedicated processes when required

• Strict control over heat treatment and testing

• Focus on long-term reliability, not shortcuts

In aerospace, details matter. We treat every critical part with the attention it deserves.

Conclusion

Nickel Alloy 718 fasteners demand more than standard machining—they require process discipline, material expertise, and uncompromising quality control.

At Honscn, we don’t simply make parts.
We deliver reliable solutions for critical applications.

If you’re sourcing Inconel 718 aerospace bolts or custom fasteners, we’re ready to support your next program.