Grade 2 vs Grade 5 Titanium Hex Bolts and Nuts
Grade 2 titanium fasteners emphasize commercially pure titanium corrosion resistance and ductility, while Grade 5 Ti-6Al-4V fasteners are selected when higher material strength and strength-to-weight ratio are required. Finished-fastener performance still depends on geometry, manufacturing, threads, heat treatment, mating parts and testing.
Material Comparison
| Item | Grade 2 | Grade 5 |
|---|---|---|
| UNS | R50400 | R56400 |
| Family | Commercially pure titanium | Ti-6Al-4V alpha-beta alloy |
| Selection focus | Corrosion-resistant joints with moderate strength requirements | Higher-strength lightweight joints after design review |
| Acceptance | The ordered fastener specification and finished-part tests control; bar properties alone are insufficient | |
Corrosion Is a Joint Question
Do not evaluate the bolt material in isolation. Review the nut, washer, clamped materials, electrolyte, crevices, temperature and galvanic area ratio. Grade 5 is not automatically more corrosion resistant than Grade 2 in every environment.
Thread Galling and Assembly
Titanium threaded pairs can gall. Define thread tolerance, surface condition, approved lubricant or coating, tightening method, installation speed and reuse policy. Trial assembly or torque-tension validation may be appropriate for critical joints.
RFQ Checklist
- Grade, material condition and finished-fastener standard
- Thread designation, tolerance and gauging
- Head, nut and washer form; diameter and length
- Mating materials, service environment and temperature
- Lubricant, coating or clean condition
- Mechanical tests, dimensions, MTC and traceability
Compare Product Options
See Grade 2 Titanium Hex Bolts and Nuts and Grade 5 Titanium Hex Bolts and Nuts. Related washers and threaded rods are available in Titanium Standard Parts.
FAQ
Can Grade 5 replace Grade 2 only because it is stronger?
No. The designer must review corrosion, stiffness, joint preload, fatigue, mating materials and the applicable fastener specification.
Should titanium bolts be installed dry?
Do not assume dry or lubricated assembly. Specify and validate the intended surface and installation procedure because it changes friction and preload.