Exotic Alloy Bolting Materials
Exotic alloys are specialized materials designed for the most demanding applications where standard materials cannot perform. These include reactive metals, refractory metals, and specialty alloys.
Titanium Fasteners
Grade 2 (Commercially Pure)
UNS R50400
Excellent corrosion resistance
Aerospace, marine applications
Grade 5 (Ti-6Al-4V)
UNS R56400
Highest strength titanium alloy
Aerospace, medical, racing
Grade 7
UNS R52400
Palladium enhanced
Chemical processing
Grade 23 (Ti-6Al-4V ELI)
Extra low interstitial
Medical implants
Highest purity
Zirconium Fasteners
Zirconium 702
UNS R60702
Superior corrosion resistance
Highly aggressive acids
Zirconium 705
UNS R60705
Niobium alloyed
Enhanced strength
Tantalum Fasteners
Tantalum R05200
Unalloyed tantalum
Extreme corrosion resistance
Chemical processing
Tantalum R05400
Ta-2.5W alloy
Higher strength
Furnace applications
Specialty Nickel Alloys
Alloy 20
UNS N08020
Sulfuric acid service
Chemical industry
Alloy 200/201
Pure nickel 99%
Caustic service
High temperature
Alloy 400 (Monel)
Nickel-copper
Seawater applications
HF acid resistance
Copper Alloys
Aluminum Bronze
C95400, C95800
Seawater resistance
Marine hardware
Silicon Bronze
C65500
Corrosion resistant
Architectural, marine
Phosphor Bronze
C51000
Spring characteristics
Electrical conductivity
Beryllium Copper
C17200
Highest strength copper alloy
Non-magnetic, non-sparking
Key Properties Comparison
| Material | Density | Key Advantages | Primary Applications |
|---|---|---|---|
| Titanium Grade 5 | 4.43 g/cm³ | High strength-to-weight, biocompatible | Aerospace, medical, racing |
| Zirconium | 6.52 g/cm³ | Excellent corrosion resistance to acids | Chemical processing, nuclear |
| Tantalum | 16.69 g/cm³ | Virtually immune to corrosion | Chemical equipment, electronics |
| Aluminum Bronze | 7.8 g/cm³ | Seawater resistance, high strength | Marine, offshore equipment |
| Beryllium Copper | 8.26 g/cm³ | Non-sparking, high strength | Hazardous environments |
Applications
Aerospace
Weight-critical titanium fasteners
Medical
Biocompatible implant hardware
Chemical Processing
Aggressive acids, high purity
Nuclear
Radiation resistance, low neutron absorption
Electronics
High temperature, conductivity
Racing/Performance
Weight reduction, high strength
Special Considerations
Titanium: Requires special handling - no galling, use anti-seize, torque carefully
Zirconium/Tantalum: Extremely expensive, used only where essential
Copper Alloys: Excellent for marine - natural antifouling properties
Beryllium Copper: OSHA requirements - toxic dust during machining
Cost Hierarchy (approximate): Tantalum > Zirconium > Titanium > Beryllium Copper > Aluminum Bronze