Closed Die Forging Manufacturer India: Process, Capability, and Critical Industry Supply

August 13, 2026


Closed die forging — shaping heated metal within matched dies that fully enclose the forging cavity is the production method for complex 3D geometry components in aerospace, defence, oil and gas, marine, and railway applications. India is already one of the world’s top five closed die forging exporters; the Indian closed die forging industry produces over 4 million tonnes annually. Vinir’s closed die forging capability covering the full range from 1 kg precision fittings to 1,400 kg structural forgings, across carbon steel, alloy steel, stainless steel, duplex, nickel alloys, and titanium serves critical-industry buyers who need AS9100D and API 20B quality alongside the cost advantage of Indian manufacturing.

Material FamilyTypical ComponentWeight RangeCertification
Carbon and alloy steel (4340, EN24, CrMoV)Valve bodies, gear blanks, shaft sections1–1,400 kgAPI 20B, IBR, ABS
Stainless steel (316L, 304L, duplex 2205)Pressure vessel nozzles, flanges, valve bodies1–800 kgAPI 20B, ASME VIII
Super duplex (2507, Zeron 100)Subsea valve bodies, offshore structural1–500 kgAPI 20B PSL 3, NORSOK M-630
Nickel alloys (Inconel 625, 718, Hastelloy C-276)Subsea, chemical, aeroengine components1–500 kgAPI 20B, AMS 5663
Titanium (CP Grade 2, Ti-6Al-4V)Marine heat exchanger, aerospace structural1–300 kgSB-381, AMS 4928

Closed die forging’s primary advantage over open die forging is the ability to produce complex 3D geometries with tight dimensional tolerances and minimal machining stock directly from the forging operation. A valve body produced by closed die forging has the inlet and outlet bore locations, flange face dimensions, and stem pocket geometry all established by the die, requiring only finish machining to achieve the final tolerance. This near-net-shape capability makes closed die forging the economic choice for medium-to-high volume production of consistently shaped components.

Vinir’s closed die presses at Bommasandra ranging from 250T for small precision fittings to 1,600T for larger structural forgings cover the weight range from 1 kg to 1,400 kg. The press capacity selection for each component is based on the projected forging force calculated from the material flow stress at forging temperature, the component’s plan area, and the estimated friction factor. For nickel alloy and titanium components, whose flow stress is 3–6× higher than equivalent steel, larger press capacity is required for the same component size.

Die design is the most critical investment in closed die forging. Vinir’s die design process begins with 3D CAD modelling of the forging geometry with appropriate forging allowances and draft angles (minimum 7° on vertical surfaces), then metal flow simulation using FEA analysis that predicts locations of potential lap formation and die under-fill before cutting any die steel. This upstream simulation investment prevents the most common first-article quality failures and ensures that production tooling immediately produces conforming forgings.

India’s closed die forging cost advantage over European and US domestic supply is typically 25–40% on an ex-works basis driven primarily by lower labour rates, energy costs, and overhead. When ocean freight is added, the landed cost advantage at a European or US customer site is typically 15–30% still commercially significant for medium-volume programmes where the die amortisation economics favour closed die over open die.

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Vinir Capability

  1. Closed die forging presses: 250T, 400T, 800T, 1,000T, 1,200T, and 1,600T at Bommasandra.
  2. Weight range 1–1,400 kg.
  3.  Materials: carbon steel (C70, SAE 1045), alloy steel (4340, EN24, 4130, CrMoV, P91), stainless steel (304L, 316L, 2205 duplex, 2507 super duplex), nickel alloys (Inconel 625, 718, Hastelloy C-276), titanium (CP Grade 2, Ti-6Al-4V).
  4. AS9100D full scope.
  5. API 20B PSL 1–3.
  6. IBR certified.
  7. ABS approved.
  8. IRIS certified.
  9. Die design using 3D CAD and metal flow FEA.
  10. Die steel: Bohler or Uddeholm hot-work steel.
  11. Lead times: carbon/alloy steel 6–10 weeks; stainless 8–12 weeks; nickel/titanium 12–18 weeks.

Frequently Asked Questions

1.What is the minimum economic order quantity (MOQ) for closed die forging?+–
The break-even between closed die and open die forging depends on the die cost, per-piece cost difference, and total programme volume. For a typical medium-complexity component (5–50 kg finished weight): a die set costing INR 15–25 lakh, closed die forgings at INR 8,000–15,000 per piece, and open die plus machining at INR 18,000–30,000 per piece the break-even is approximately 100–200 pieces total production. Below this volume, open die is more economical; above it, closed die pays back the die investment and produces lower per-piece costs for all subsequent production.
2.What draft angle is required for closed die forging and why?+–
Draft angle is the angle between the vertical surface of the die cavity and the press direction necessary so that the forging can be ejected from the die after the press stroke. Insufficient draft causes the forging to stick in the die cavity, damaging both the forging and the die. The minimum draft angle for most closed die forgings is 5–7° on external surfaces and 7–10° on internal surfaces. For complex internal cavities (valve body flow paths, deep pockets), draft angles of 10–15° are sometimes required to ensure reliable ejection.
3.How does material selection affect the choice of press capacity for closed die forging?+–
The forging press capacity required is calculated as: Forging Force = Flow Stress × Plan Area × Friction Factor. At typical forging temperatures, the flow stress varies significantly by material: carbon steel 15–30 MPa, alloy steel (4340) 20–40 MPa, stainless steel (316L) 30–60 MPa, duplex stainless 40–80 MPa, Inconel 625 60–120 MPa, Ti-6Al-4V 30–60 MPa. A 100 kg valve body in carbon steel can be forged on a 400T press; the same geometry in Inconel 625 requires an 800–1,200T press because the flow stress is 4–5× higher. This relationship explains why nickel alloy closed die forgings are significantly more expensive than equivalent carbon steel forgings.
4.What is the difference between blocker (preform) and finisher dies in a multi-stage closed die forging sequence?+–
Multi-stage closed die forging uses two or more die impressions in sequence to progressively shape the billet from its starting geometry to the final forging shape. The blocker die provides an intermediate shape that distributes metal into approximately the right locations for the finisher die without attempting to achieve the final geometry. The finisher die then closes the forging to its final dimensions with the flash line providing the final pressure to fill every corner of the die cavity. Multi-stage forging reduces die wear, reduces flash, and improves grain flow control.
5.What quality records does Vinir provide with each batch of closed die forgings?+–
Each batch of closed die forgings from Vinir is accompanied by: Mill Material Test Report (MTR) tracing the raw material to the steel mill’s heat, NABL-accredited chemical analysis report (OES) confirming chemistry, NABL-accredited mechanical test report (tensile, Charpy at specified temperature), heat treatment record (furnace chart showing the complete time-temperature profile), NDT reports (UT, MT, and/or PT as specified), dimensional inspection report, and Certificate of Conformance (CoC) signed by Vinir’s responsible quality officer. For AS9100D aerospace programmes, the AS9102 FAIR is prepared for the first article of each new part number.