Heli-Coil vs Threaded Inserts: A Technical Comparison

Core Functional Differences

 

While both provide durable threaded solutions, Heli-Coil and threaded inserts serve

 

 

 keyworddistinct purposes:

• Heli-Coil: Best for thread repair/reinforcement in metal applications
• Threaded Inserts: Ideal for creating new threads in soft materials

Heli-Coil Insert Characteristics

Unique Design Features:

• Precision helical coil configuration
• Even load distribution across threads
• Mechanical locking under vibration/stress
• 30-40% increased bearing surface vs standard threads

Material Advantages:

• 300 series stainless steel standard
• Corrosion resistance to 500+ hours salt spray
• Operating range: -200°C to +650°C
• Vibration resistance up to 50G acceleration

Optimal Applications:

• Aerospace turbine components
• Automotive engine blocks
• Industrial equipment rebuilds
• Medical device assemblies

Threaded Insert Varieties

Structural Types:

1. Self-tapping (for plastics/soft metals)
2. Press-fit (for wood/composites)
3. Heat-set (for thermoplastics)

Material Options:

• Stainless steel (Grade 304/316)
• Carbon steel (Grade 8.8/10.9)
• Brass (CZ121/CZ124)
• Zinc alloy (Zamak 3/5)

Industry Applications:

• Plastic injection molding (heat-set)
• Furniture manufacturing (press-fit)
• Electronics enclosures (self-tapping)
• Marine hardware (316 stainless)

Performance Comparison

Load Capacity:

Metric	Heli-Coil	Threaded Insert
Tensile Strength	900 MPa	700-1200 MPa
Shear Strength	600 MPa	450-800 MPa
Fatigue Life	10⁷ cycles	10⁶ cycles

Corrosion Resistance:

• Heli-Coil: Superior in acidic/alkaline environments
• Threaded Inserts: Better for marine applications (with 316SS)

Installation Complexity:

• Heli-Coil requires:
  • Precision tapping (Class 3B)
  • Special installation tooling
  • 0.005" interference fit
• Threaded inserts feature:
  • Self-tapping options (no pre-tapping)
  • Press-fit installation (hammer/drill)
  • Heat-set bonding (300-400°F)

QEWIT Technical Solutions

Manufacturing Capabilities:

• ISO 9001:2015 certified production
• 30,000+ SKU inventory
• Custom thread forms (UN, Metric, PG)
• Special coatings (Zn-Ni, Dacromet)

Quality Assurance:

• 100% dimensional inspection
• Material traceability (3.1 certs)
• Salt spray testing per ASTM B117
• Vibration testing per MIL-STD-810

Selection Guidelines

Choose Heli-Coil When:

• Repairing stripped threads
• Working with aluminum/magnesium
• High vibration environments
• Precision aerospace applications

Opt for Threaded Inserts When:

• Joining dissimilar materials
• Working with plastics/woods
• Need quick installation
• Require flush mounting

Industry-Specific Recommendations

Automotive:

• Heli-Coil for engine components
• Brass inserts for electrical systems

Aerospace:

• Hi-temp Heli-Coil for turbines
• Titanium inserts for airframes

Medical:

• Biocompatible Heli-Coil
• Sterilizable 316L inserts

FAQ

Q1: What's the temperature limit for standard Heli-Coils?

A: 650°C continuous (Inconel versions available to 1100°C)

Q2: Can threaded inserts be removed/reused?

A: Only press-fit types (self-tapping/heat-set are permanent)

Q3: Minimum material thickness for Heli-Coil?

A: 1.5x thread diameter (M6 = 9mm minimum)

Q4: Lead time for custom inserts?

A: 2-3 weeks for prototypes, 4-6 weeks production