Forging or machining from bar is decided by the part, not by preference
Both routes carry the same grade designations across their two specifications. What differs is where the material starts, how much of it becomes chips, and which standard the certificate is written against. For a given part one route is usually obvious once the finished dimensions are on the table.
| What the route decides |
|---|
| Which governing standard the order runs under |
| The starting stock the part is cut from |
| Whether a drawing is required before the line can be quoted |
The two routes sit under different standards
This is the part buyers most often leave open. Naming the grade without naming the route leaves the mill to choose, and the certificate then names a standard the drawing may not accept.
| Route | Governing standard | Ordered against |
|---|---|---|
| Forging | ASTM B381 | A drawing |
| Machining from bar or billet | ASTM B348 | A size from the bar range |
The reachable sizes are not the same
The bar route reaches the smallest sections and the longest lengths. The forging route reaches ring, disc and block shapes that no bar section produces. At round bar the two ranges reach the same 500 mm, so diameter alone does not decide the route.
| Form | Range Beiyu reviews against |
|---|---|
| Round bar, ASTM B348 | 1 mm to 500 mm diameter, length to 6000 mm |
| Forged round bar, ASTM B381 | 50 mm to 500 mm diameter, length to 3000 mm |
| Ring, forged | Outside diameter 50 mm to 2000 mm, inside diameter 10 mm to 900 mm, height 20 mm to 400 mm |
| Disc, forged | Outside diameter 50 mm to 2000 mm, thickness 20 mm to 500 mm |
| Block, forged | 50 mm to 600 mm, governing dimension from the drawing |
The envelope is a production capability, not a stock statement, and the ordered combination is confirmed at quotation.
Where each route is the sensible one
| Part condition | Route it points to |
|---|---|
| Finished part fits inside a standard bar section | Machining from bar to ASTM B348 |
| Outside diameter required is above the 500 mm the bar range reaches | Forging to ASTM B381, where ring and disc reach 2000 mm |
| Part is a ring, a disc or a block rather than a bar section | Forging to ASTM B381 |
| Long, small diameter, repeated in quantity | Machining from bar to ASTM B348 |
Grade naming changes between the two standards
ASTM B381 uses its own designations for forgings, so the same alloy is written differently depending on which route the line runs under. An order naming only the commercial grade leaves the mill to map it, and that is where certificates start disagreeing with drawings.
| Commercial name | Under ASTM B381 | UNS |
|---|---|---|
| Grade 2 unalloyed titanium | Grade F-2 | R50400 |
| Grade 5 Ti-6Al-4V | Grade F-5 | R56400 |
| Grade 7 palladium-bearing unalloyed titanium | Grade F-7 | R52400 |
| Grade 12 Ti-0.3Mo-0.8Ni | Grade F-12 | R53400 |
What to state on the purchase order
Route: ______ (forging, or machining from bar and billet) Governing standard: ______ (ASTM B381 for forgings, ASTM B348 for bar and billet) Grade: ______ (state the commercial name and, for forgings, the B381 designation) UNS: ______ Drawing: ______ (attach it where the route is forging) Finished dimensions and machining allowance: ______ Condition: ______ (R / M, stated on the order) Examination scope: ______ (method, coverage, acceptance standard, class and stage) Certificate: EN 10204 3.1 mill test certificate with heat number traceability, reporting scope by order
Send the finished dimensions before asking which route is cheaper. Beiyu reviews the part against both envelopes and confirms the grade, size and standard combination before quoting.
Specification detail with sources
The two routes are linked at the material level, not separated by it. ASTM B381 states in its materials and manufacture clause that material conforming to ASTM B348 shall be used when producing forgings to that specification (ASTM B381, materials and manufacture). So a forging does not start from a different metal than bar; it starts from bar and billet stock and is then worked to shape, which ASTM B381 defines as any product formed to a desired shape by impact or pressure in hammers, forging machines, upsetters, presses or related forming equipment (ASTM B381, terminology).
| Field | ASTM B348, bar and billet | ASTM B381, forgings |
|---|---|---|
| What the order is placed against | A size from the bar range | A drawing |
| Bar and billet boundary | Bar is a solid section of 16 sq in (10 323 sq mm) cross section or less; billet is above that, with width under five times thickness | ASTM B381 carries its own bar and billet definitions in its terminology clause |
| Grade designation on the certificate | Grade 2, Grade 5, Grade 7, Grade 12 | Grade F-2, Grade F-5, Grade F-7, Grade F-12 |
Both standards route their chemistry and mechanical reporting through the same test methods. ASTM B381 lists ASTM E8 for tension testing, ASTM E1409 for oxygen and nitrogen by inert gas fusion, ASTM E1447 for hydrogen, ASTM E1941 for carbon by combustion and ASTM E2371 for plasma atomic emission analysis (ASTM B381, referenced documents). Naming a test method on the order settles how a value is produced. It does not by itself set the acceptance limit, which comes from the chemical and tensile tables of the product specification, and it does not decide the sampling plan, which is a separate clause. In Beiyu’s supply practice the route, the standard and the examination scope are confirmed against the drawing before pricing.
Send a technical RFQ
For titanium forging and bar RFQs, include the route, the governing standard, grade and UNS, the drawing where the route is forging, finished dimensions and machining allowance, condition, examination scope with its acceptance basis, and the required mill test certificate.