At a glance
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| Comparison | Grade 2 | Grade 5 |
|---|---|---|
| Material family | Commercially pure titanium | Alpha-beta titanium alloy (Ti-6Al-4V) |
| Primary purchasing reason | Corrosion-focused service, formability and ductility | Higher strength and strength-to-weight performance |
| Manufacturing tendency | Generally more formable and weldable | Stronger but typically more demanding to machine and form |
| Fastener decision | Use only when the required joint load and specification support it | Use when the design genuinely requires the additional strength |
| Documentation | Confirm material standard, heat or lot link and test certificate scope | Confirm alloy condition, fastener requirements and certificate scope |
01
Start with the joint—not the grade number
A fastener grade cannot be selected from corrosion resistance or tensile strength alone. The responsible engineer must define the target preload, external loads, fatigue duty, grip length, thread engagement, bearing surfaces, mating materials and installation method. A stronger bolt does not correct a weak tapped hole or an unsuitable joint design.
For purchasing, the most useful starting package is the controlled drawing or fastener standard, required titanium grade, thread and tolerance, quantity, surface condition, service environment, inspection points and document list.
Purchasing note: MetalPartSource prioritizes Grade 2 enquiries for seawater equipment and retains Grade 5 sourcing as a secondary option when specified. Confirm the approved grade, condition and governing requirements with the responsible engineering team.
02
Where Grade 2 tends to fit
Grade 2 belongs to the commercially pure titanium family. Buyers often evaluate it for corrosion-focused industrial service and parts that benefit from ductility or forming. In fasteners, however, its lower strength relative to Grade 5 must be checked against the actual joint requirement rather than assumed acceptable because the environment is corrosive.
If seawater, brine or chemical exposure drives the enquiry, include temperature, aeration, concentration, crevices and cleaning chemicals. Material suitability remains a project engineering decision, particularly where localized corrosion or mixed-metal contact may matter.
03
Where Grade 5 tends to fit
Grade 5 is Ti-6Al-4V and is widely used when higher material strength and low mass are important. It can be appropriate for loaded studs, bolts and custom machined fasteners, provided the drawing, fastener specification, alloy condition and acceptance tests are clear.
Higher material strength does not provide a universal tightening torque. Torque and preload depend on thread geometry, friction, lubrication, bearing surfaces and the complete joint. Installation values should come from the responsible engineering procedure.
04
Standards and records belong in the RFQ
ASTM F468 covers certain wrought nonferrous bolts, cap screws and studs for general service, while ASTM F468M is its metric companion; applicable nuts are addressed separately. A buyer should confirm whether these or another customer, industry or drawing specification governs the item.
State whether the order requires an MTC or EN 10204 3.1 document where applicable, heat or lot traceability, dimensional records, marking, mechanical testing, sampling or third-party inspection. Availability must be confirmed against the chosen supply route before commitment.
FAQ
Frequently asked questions
Is Grade 5 always better than Grade 2 for bolts?
No. Grade 5 offers much higher material strength, but the joint, service environment, mating materials, manufacturing route and governing specification determine whether that strength is useful or appropriate.
Can Grade 2 fasteners be used in seawater?
Commercially pure titanium is widely associated with seawater corrosion resistance, but a specific fastener still requires engineering review of load, temperature, crevices, galvanic interfaces and the project specification.
Can I use a generic torque value for titanium fasteners?
No generic value should be assumed. Torque-to-preload behavior depends on friction, lubrication, thread geometry, bearing surfaces and the joint design. Use a qualified installation procedure.
What should I send for a Grade 2 or Grade 5 RFQ?
Send the drawing or standard, grade, condition if specified, dimensions, thread, quantity, destination, required date, service context and documentation or inspection requirements.
Technical references
Use the current project specification and applicable standard as the controlling source. The following references provide background for this guide.