Titanium Forging: Process Comparison, Grade Selection, and Cost-Per-Part Data for OEM Procurement

Why Forging Remains the Gold Standard for Critical Titanium Components

When a titanium part must withstand cyclic fatigue loads exceeding 500 MPa for 10⁷ cycles, resist crack propagation in safety-critical airframe structure, or survive decades of corrosive service in subsea equipment, forging is the process that engineers specify — not casting, not machining from billet, and not additive manufacturing. The reason is metallurgical: the thermomechanical deformation inherent in forging refines grain structure, closes internal porosity, and aligns the metal's crystallographic texture along the primary stress axis. The result is a part with superior fatigue life, fracture toughness, and directional strength compared to the same geometry produced by any competing near-net-shape process.

But "titanium forging" is not a single process. Open-die forging, closed-die (impression-die) forging, and precision forging each offer fundamentally different trade-offs in dimensional tolerance, material yield, tooling investment, and minimum order economics. Selecting the wrong process for your application can add 30–60% to part cost without improving performance — or, worse, deliver a part that fails to meet the mechanical property minimums required by your specification. This guide provides the quantitative framework that procurement engineers and design teams need to make that decision correctly.

The Three Forging Processes Compared

Open-Die Forging

Open-die forging — also called free forging or smith forging — deforms the titanium workpiece between flat or simple-contour dies without fully enclosing the material. The operator controls shape through a sequence of upsetting, drawing, and cogging operations, rotating and repositioning the billet between press strokes. This process is the foundation of titanium forging: every closed-die forging starts from an open-die preform, and many large structural components are finished directly as open-die forgings.

The process excels at producing large, simple geometries — shafts, discs, rings, blocks, and stepped cylinders — in weights from 50 kg to over 10,000 kg. Dimensional tolerances are necessarily wider than closed-die work, typically ±3 mm to ±10 mm depending on geometry, but the process offers unmatched flexibility: tooling cost is negligible, lead times for new parts are measured in weeks rather than months, and minimum order quantities can be as low as a single piece. For prototype programs, bridge production runs, and one-off replacement parts, open-die forging delivers wrought-quality material properties without the tooling investment of impression-die work.

Closed-Die (Impression-Die) Forging

Closed-die forging confines the titanium billet within a pair of shaped die cavities that define the final part geometry. Under press loads of 20,000–80,000 tonnes, the heated billet flows to fill the die impression, with excess material extruding into a flash gutter around the parting line. The flash is subsequently trimmed, and the forging is heat-treated to achieve final properties.

This process delivers tighter tolerances (±0.5 mm to ±2.0 mm), better surface finish (Ra 3.2–6.3 μm as-forged), and significantly higher material yield than open-die work — particularly for complex geometries with ribs, bosses, and varying cross-sections. The trade-off is tooling: a matched set of titanium forging dies in H13 tool steel, heat-treated to 44–48 HRC and typically requiring 200–400 hours of CNC machining and EDM, represents an investment of $15,000–$80,000 depending on part complexity. This investment is amortized over production volume, making closed-die forging most economical at quantities above 50–100 pieces per year.

Precision Forging

Precision forging — sometimes called near-net-shape forging or hot-die forging — uses heated dies (maintained at 600–800°C for titanium alloys) and tighter process controls to produce forgings that require minimal or no machining on critical surfaces. Die temperatures closer to the workpiece temperature reduce thermal gradients, allowing more uniform material flow and tighter tolerances (±0.3 mm to ±1.0 mm). Some precision-forged titanium components go directly to surface treatment and assembly without any machining, achieving buy-to-fly ratios below 1.5:1 compared to 5:1–15:1 for conventionally machined parts.

The process demands specialized equipment — isothermal presses with heated die tooling, inert-atmosphere enclosures to prevent alpha case formation, and advanced FEA-based process simulation for die design. Tooling costs are 2–3× higher than conventional closed-die work. But for high-volume aerospace components such as compressor blades, turbine discs, and structural fittings produced in quantities of 500+ per year, the machining savings and material yield improvements can reduce total part cost by 20–40%.

Process Selection Matrix

Parameter	Open-Die	Closed-Die	Precision
Typical tolerance	±3–10 mm	±0.5–2.0 mm	±0.3–1.0 mm
Surface finish (Ra)	12.5–25 μm	3.2–6.3 μm	1.6–3.2 μm
Part weight range	50–10,000+ kg	0.5–500 kg	0.1–50 kg
Tooling cost	$0–5,000	$15,000–80,000	$40,000–200,000
Die life (Ti-6Al-4V)	N/A	2,000–5,000 pcs	1,000–3,000 pcs
Material yield	40–60%	65–80%	85–95%
Buy-to-fly ratio	8:1–20:1	3:1–8:1	1.3:1–3:1
Min. economic qty	1 pc	50–100 pcs	500+ pcs
Lead time (new part)	3–6 weeks	10–16 weeks	16–24 weeks
Best applications	Shafts, discs, blocks, rings, preforms	Structural fittings, landing gear, connectors	Compressor blades, discs, high-vol aero parts

Grade Selection for Titanium Forgings

Not all titanium alloys forge equally. The forging temperature window, flow stress, and post-forging heat treatment requirements differ significantly between commercially pure grades and alpha-beta or beta alloys. The following table summarizes the key forging parameters and resultant mechanical properties for the grades most commonly specified in forged components.

Mechanical Properties of Common Forging Grades (Per AMS/ASTM Specifications)

Grade	Specification	Forging Temp (°C)	UTS (MPa)	Yield (MPa)	Elongation (%)	RA (%)	Fatigue Limit (MPa, 10⁷)	Primary Applications
Gr.2 (CP)	ASTM B381 F2	800–950	≥345	≥275	≥20	≥30	~170	Chemical processing, marine hardware
Gr.4 (CP)	ASTM B381 F4	800–950	≥550	≥483	≥15	≥25	~250	Medical implants (ASTM F67)
Gr.5 (Ti-6Al-4V)	AMS 4928	900–970 (α+β)	≥896	≥827	≥10	≥25	~510	Aerospace structural, landing gear
Gr.5 ELI (Ti-6Al-4V ELI)	AMS 4930	900–960	≥860	≥795	≥10	≥25	~480	Medical implants (ASTM F136), cryo
Gr.9 (Ti-3Al-2.5V)	AMS 4943	850–950	≥620	≥483	≥15	≥30	~350	Hydraulic tubing, lightweight fittings
Gr.19 (Ti-5553)	AMS 4957	800–880 (β)	≥1,241	≥1,172	≥6	≥15	~580	Landing gear, high-strength structure
Gr.23 (Ti-6Al-4V ELI)	ASTM F136	900–960	≥860	≥795	≥10	≥25	~480	Orthopedic implants, spinal devices

Alpha-Beta vs. Beta Forging

The forging temperature relative to the beta transus temperature (Tβ) is the single most consequential process variable for alpha-beta alloys like Ti-6Al-4V. Forging below Tβ (approximately 995°C for Ti-6Al-4V) — known as alpha-beta forging — produces a bimodal microstructure with equiaxed primary alpha grains in a transformed beta matrix. This microstructure delivers the best combination of strength, ductility, and high-cycle fatigue resistance, making it the standard choice for rotating components and fatigue-critical structure.

Forging above Tβ — beta forging — produces a fully lamellar microstructure with coarse prior-beta grains containing aligned alpha platelets. This microstructure sacrifices some ductility and high-cycle fatigue strength but delivers superior fracture toughness and fatigue crack growth resistance. Beta-forged Ti-6Al-4V is specified for damage-tolerant airframe structure where crack growth rate, not crack initiation resistance, governs inspection intervals and component life. The Boeing 787 and Airbus A350, for example, use beta-forged Ti-6Al-4V bulkheads and frames in fuselage sections designed to damage-tolerance philosophy.

Cost Structure Breakdown

Understanding where cost accumulates in a titanium forging enables more effective procurement negotiation and design-for-manufacturing optimization. The following breakdown reflects typical cost allocation for a medium-complexity closed-die Ti-6Al-4V forging weighing 5–20 kg, produced in annual quantities of 200–500 pieces.

Cost Element	% of Total	Key Drivers
Raw material (billet)	30–40%	Ti sponge price, alloy additions, melt method (VAR vs. CCHM)
Die tooling (amortized)	8–15%	Part complexity, die life, annual volume
Forging labor + press time	15–20%	Number of forging operations, press tonnage, heating cycles
Heat treatment	5–8%	STA vs. anneal, atmosphere (vacuum vs. air), cycle time
NDT (UT, FPI, dimensional)	5–10%	Spec requirements (AMS 2630/2631), critical zone coverage
Machining (post-forge)	15–25%	Buy-to-fly ratio, surface finish requirements, tolerance class
Overhead + certification	5–10%	AS9100/Nadcap audits, material traceability, documentation

Material Cost Sensitivity

Titanium billet represents the largest single cost element, and procurement strategy directly impacts total part cost. Key considerations include specifying the minimum grade that meets your mechanical property requirements. Over-specifying Ti-6Al-4V where CP Grade 2 would suffice adds $15–25/kg to raw material cost — a difference that compounds through the entire manufacturing chain because higher-alloy grades require more expensive tooling, slower forging speeds, and more aggressive heat treatment cycles.

Additionally, forging stock dimensions should be optimized during design. A billet that is 10 mm larger in diameter than necessary wastes 15–25% more material in flash loss alone. Working with your forging supplier during the design phase to optimize preform geometry and forging stock dimensions typically reduces material waste by 10–20%, which translates directly to part cost reduction of 3–8%.

Specification and Quality Requirements

Aerospace Forgings

Aerospace titanium forgings are governed by a matrix of material, process, and inspection specifications that procurement engineers must flow down correctly to avoid non-conformances and delivery delays.

Material specifications define chemistry, mechanical properties, and microstructure requirements. AMS 4928 (Ti-6Al-4V bars, forgings, and rings, annealed) and AMS 4967 (Ti-6Al-4V forgings, STA) are the most commonly specified for structural applications. Process specifications govern forging parameters: AMS 2750 (pyrometry), AMS 2759/9 (heat treatment of titanium), and AMS 2631 (ultrasonic inspection of titanium forgings) are typically mandatory callouts.

Non-destructive testing requirements for aerospace forgings typically include 100% ultrasonic inspection per AMS 2631 Class A (flat-bottom hole sensitivity of #3 FBH or finer), fluorescent penetrant inspection per AMS 2647, and dimensional inspection per the applicable drawing with CMM reporting. Nadcap accreditation for heat treatment, NDT, and special processes is a common customer requirement that limits the supplier base significantly.

Medical Forgings

Medical titanium forgings require ASTM F136 (Ti-6Al-4V ELI) or ASTM F67 (CP titanium) material compliance, with additional requirements for biocompatibility testing per ISO 10993, surface cleanliness, and full material traceability from sponge to finished part. Medical device OEMs increasingly require their forging suppliers to maintain ISO 13485 quality management systems in addition to the base ISO 9001 certification.

Industrial Forgings

Industrial applications — chemical processing, oil and gas, marine, and power generation — typically specify ASTM B381 (titanium forgings) with grade-specific requirements. Inspection and documentation requirements are generally less stringent than aerospace, but corrosion testing (ASTM G48, ASTM B117) and pressure-boundary NDT requirements (ASME Section V) apply to pressure-containing forgings.

Procurement Decision Framework

Selecting the right forging source requires evaluating capabilities across multiple dimensions. The following decision framework reflects the evaluation criteria that experienced procurement teams prioritize.

First, match the forging process to your production volume and tolerance requirements. For annual quantities below 50 pieces or part weights above 500 kg, open-die forging provides the best economics. For 50–500 pieces per year with moderate complexity, closed-die forging optimizes the cost-tolerance balance. For 500+ pieces per year with tight tolerances and complex geometry, precision forging delivers the lowest total cost despite higher tooling investment.

Second, verify the supplier's grade-specific experience. Forging Ti-6Al-4V is fundamentally different from forging CP Grade 2 — the flow stress is 3× higher, the forging window is narrower, and microstructure control requires precise temperature management within ±15°C. A supplier with extensive CP titanium experience may lack the process controls, press capacity, and metallurgical expertise to produce aerospace-quality Ti-6Al-4V forgings.

Third, evaluate the supplier's vertical integration. A forging supplier that also performs heat treatment, machining, and NDT in-house eliminates inter-supplier logistics delays, reduces handling damage risk, and provides single-source accountability for the finished part. For programs requiring 100% traceability from melt source to delivered part, vertical integration simplifies the documentation chain and reduces the risk of material substitution or mixing.

BAOTI's Forging Capabilities

BAOTI operates a fully integrated titanium forging operation spanning the complete process chain from sponge production through finished machined forgings. The facility includes a 40,000-tonne hydraulic press — one of the largest titanium forging presses in Asia — capable of producing closed-die forgings up to 4,500 mm in length. Precision forging capabilities include isothermal forging with heated dies for compressor blade and disc production.

The operation holds AS9100D, ISO 9001:2015, ISO 13485, and Nadcap accreditation for heat treatment and NDT. Material is melted in-house via vacuum arc remelting (VAR), providing full traceability from titanium sponge through finished forging. Current production supports aerospace OEMs, medical device manufacturers, and industrial equipment builders across North America, Europe, and Asia.

For forging inquiries, engineering consultation, or budgetary quotation, contact our technical sales team through the inquiry form with your part drawing, material specification, annual volume, and delivery requirements.