Overview
ASTM B348/B348M-25 covers annealed titanium and titanium-alloy bars and billets. Procurement must distinguish bar from billet and specify grade, section, length, annealed condition, surface preparation, dimensional tolerance, tensile testing, interstitial chemistry and intended machining or forging route.
Designation and acceptance
B348/B348M uses titanium grade and UNS identities familiar from other product forms, but bar/billet acceptance is specific to this document. Material may be supplied with descaled, sandblasted, ground or rough-turned surfaces as ordered. A billet intended for further working is not a finished bar, and B348 stock is not automatically a certified forging, aerospace bar or medical implant material.
Members and selection
| Designation | Selection context |
|---|---|
| Round bar | Specify diameter, length, straightness, surface and machining allowance for the finished-stock route. |
| Rectangular or other bar | Provide section, corner, straightness and tolerance requirements within available mill capability. |
| Billet | State dimensions, working route, surface removal and downstream forging/extrusion qualification. |
| Grade/condition family | Pair CP, alloy or H grade with annealed condition and the exact property/test basis. |
Comparison framework
| Criterion | Decision context |
|---|---|
| Bar vs billet | Bar is ordered closer to a finished long-product geometry; billet is semi-finished feedstock for further working. |
| Surface route | Descaled, blasted, ground and rough-turned surfaces have different defect visibility and machining allowance. |
| Grade vs product | The same titanium grade under B265 flat product does not establish B348 bar dimensions or acceptance. |
| Industrial vs special qualification | Aerospace, medical and rotating-critical parts require their own approved specifications and process controls. |
Performance
- Acceptance under ASTM B348 Titanium Bars depends on the exact alloy or grade, delivered condition, product geometry and specified test basis rather than the standard number alone.
- Surface contamination, laps, alpha case, hydrogen pickup and insufficient conversion history can affect downstream integrity.
- Service suitability remains an engineering decision: bar or billet conformance does not qualify the final forging, machining process, fatigue life or regulated end use.
Orderable product scope
- Annealed round titanium bar for machining and fabricated components.
- Annealed rectangular or special-section bar within agreed dimensional capability.
- Titanium billet for subsequent forging, extrusion or other qualified conversion.
Processing
- Remove contaminated alpha case or surface defects only under a controlled stock-removal plan.
- Use tooling and coolant practices that control heat, galling and ignition risk during machining.
- Qualify forging and heat treatment from grade, billet history, reduction and final property requirements.
Applications
- Machined corrosion-resistant fastener, shaft and valve-component stock.
- Industrial titanium components made from CP or alloy long products.
- Billet feedstock for qualified forgings or extrusions where B348 is accepted as the starting material.
Selection
- Confirm that ASTM B348 Titanium Bars actually covers the required product form and manufacturing route before comparing grades or quotations.
- Select alloy or grade and delivered condition from service, fabrication, section size and required property evidence; do not infer condition from a trade name.
- Require a written technical comparison and responsible-engineer approval before substituting another standard, alloy, condition or product route.
Procurement
- State ASTM B348/B348M-25, exact grade/UNS, bar or billet, section and annealed condition.
- State diameter/section, length, quantity, straightness, dimensional tolerances and end condition.
- Specify descaled, blasted, ground or rough-turned surface, machining allowance and special examination.
- Require chemistry/tensile report, heat and conversion-lot traceability, marking and contamination-safe packaging.