Titanium Slabs and Billet | Forging and Rolling Stock

Titanium billet is semi-finished conversion stock, hot worked or forged from ingot to a cross-section larger than 16 in.², and converted onward into forgings, bar or other mill product. It is covered by ASTM B348, the same specification that covers titanium bar, and it is ordered by grade, section size, condition and the certificate the downstream standard requires.

What is titanium billet, and how does it differ from ingot, slab and bar?

ASTM B348 separates bar from billet by cross-section, not by how far along a process route the material sits. Under the standard, bar is a semi-finished solid section of 16 in.² or less, while billet is hot worked or forged from ingot, has a cross-section larger than 16 in.², and has a width less than five times its thickness. Slab is broad flat stock for the rolling route and is a different form again. Ingot is the melted form the others are worked from, produced by vacuum arc remelting or other consumable melting routes. These are related product forms rather than four sequential stages, which is why one order can legitimately call for bar and another for billet out of the same heat.

The practical difference on an order is the cross-section and what the material is expected to do next. Bar is normally bought to be cut and machined. Billet is bought to be forged, extruded or rolled again, so the buyer cares about section size, internal soundness and the starting condition rather than a finished surface.

Titanium billet grades, UNS numbers and chemistry

ASTM B348 covers bars and billets across the commercially pure and alloyed titanium grades. The grades below are the ones ordinarily ordered as conversion stock. Limits are heat analysis maximums in percent unless the entry says otherwise.

Note the Grade 23 row. Under ASTM B348, B265, B863 and B381 the ELI grade is UNS R56407; only the surgical implant specification ASTM F136 designates its Ti-6Al-4V ELI as UNS R56401. Ordering ELI billet against the wrong number is a routine cause of certificate disputes, and the distinction is set out in our Grade 23 titanium data sheet.

Mechanical properties: why the B348 table does not settle a billet order

This is the point that causes the most argument at goods inward. ASTM B348 Table 2 gives its mechanical minimums for sections up to 3 in. thick and up to 10 in.² in area. Billet, by the standard's own definition, has a cross-section larger than 16 in.², so those figures sit outside the range they were written for. Mechanical requirements for billet-size sections are agreed between the purchaser and the manufacturer, and that agreement belongs on the purchase order rather than being assumed from the table. The values below are the Table 2 reference minima in the annealed condition, useful for the grade comparison and for the bar-size end of an order, not automatically an acceptance standard for a large billet.

ASTM B348 also sets a reduction of area minimum that ASTM B265 flat product does not carry, and tension testing follows Test Methods E8 and E8M. Where the billet will be converted further, the properties that matter are usually those of the finished part after conversion, so the order should state whether the acceptance test applies to the billet as supplied or to the converted product.

Billet as forging stock, and where slab sits

ASTM B381 section 5.1 requires the material used for forgings to conform to ASTM B348, so a purchase order written to B381 already imposes the stock requirement; it does not have to be argued for. Citing B348 separately is worth doing when the stock has to be reported and certified in its own right, for example when the buyer wants a certificate for the billet as delivered as well as for the finished forging. Where billet feeds a rolling or extrusion route instead, state which standard the finished form will be accepted against, because that is not implied by the stock standard.

Slab is the exception buyers most often overlook. ASTM B348 does not cover slab, so a slab requirement has to be written out on the purchase order in its own terms: chemistry, condition, dimensions and any inspection. Beiyu Titanium supplies ASTM B348 billet with EN 10204 3.1 mill test certificates traceable to the production heat, and supplies slab to the chemistry, condition and dimensions agreed on the order. Our ASTM B381 forgings guide covers the forging side, and the ASTM B348 bar and billet guide covers the stock side.

Standards and equivalents for titanium billet

Where a drawing carries a German material number rather than an ASTM grade, the titanium grade cross-reference tool maps the designations against each other.

How to specify titanium billet on an order

A billet enquiry that can be quoted without a second round of questions states seven things: the grade and UNS number; the governing standard, normally ASTM B348 or its ASME equivalent; the section shape and size, round or square, with the tolerance that matters for the conversion route; the length or the piece weight; the condition, as-forged, annealed or as agreed; what the billet will be converted into and against which standard that finished form will be accepted; and the certificate requirement, normally EN 10204 3.1 with heat-number traceability. Beiyu Titanium supplies titanium billet and slab to ASTM B348 with EN 10204 3.1 mill test certificates traceable to the production heat.