Near-Net-Shape Forged Gear Blanks — OD 50–1200 mm, All Gear Types
Shivam Forge manufactures closed-die forged gear blanks — spur, helical, bevel, ring, planetary and sun gears — in EN36, SAE 8620, EN19 (42CrMo4) and EN24 (4340) at Shapar GIDC, Rajkot. OD range 50–1200 mm. Grain flow aligned to tooth root for maximum bending fatigue life. Hobbing allowance 3–5 mm per side. Call +91 92657 72827.
A gear blank that has been correctly forged — with grain flow following the tooth profile and minimum porosity across the tooth root section — will consistently outlast a blank machined from bar stock or produced by casting. The fatigue loading at a gear tooth root during power transmission is severe, and the oriented grain structure that hot forging develops is the most effective way to extend tooth-bending fatigue life. Shivam Forge has designed its gear blank forging capability around this principle: near-net-shape closed dies that minimise hobbing allowance to 3–5 mm per side, grain flow certification as standard, and material selection matched to the case hardening or through-hardening route specified by the gear manufacturer.
Straight-tooth spur gear blanks in OD range 50–1000 mm, forged solid or with a pierced centre bore. Near-net-shape forging minimises hobbing allowance to 3–5 mm per face and 5–8 mm on OD, reducing gear-hobbing machine cycle time and cutting tool consumption. Supplied annealed to ≤207 HB for machinability, or normalised as specified.
Forged helical gear blanks in EN19 (42CrMo4) and SAE 8620 for high-speed gearboxes, industrial drives and automotive transmission shafts. The closed-die forging process produces a blank with superior cleanliness and tighter dimensional consistency than casting — critical when helical gear geometry requires precise tooth flank geometry after hobbing and shaving or grinding.
Spiral and straight bevel gear blanks in EN19, SAE 8620 and EN24 for differential drives, bevel gearboxes and marine propulsion systems. Bevel gear forging geometry presents unique die design challenges — the taper angle must be forged accurately to minimise post-forging machining on the face cone. Our bevel gear blank tooling is engineered to hold face taper within ±1° as forged.
Large ring gear blank forgings in EN24 (4340) and EN19 for planetary gearboxes, slewing rings, swing drive systems and industrial ring gears. OD up to 1200 mm, forged as a solid disc or ring blank with pre-forged bore. For ring gears where weight saving matters — wind turbine planetary stages, excavator slewing rings — we can forge to near-net ring profile to minimise rough machining of the OD and bore.
Compact forged blanks for planetary gear sets — sun gears, planet gears and ring gear blanks — in EN36 (20NiCrMo2) and SAE 8620 for case hardening applications, or EN19 (42CrMo4) for through-hardened planet gears. Planetary gear sets used in wind turbine nacelles, excavator final drives and industrial gear units demand consistent grain flow to meet the tooth-bending fatigue cycles specified in ISO 6336.
Integral cluster gear blanks and gear shaft blanks in one forged piece, eliminating joining interfaces and improving power transmission reliability. EN19 and EN24 shaft gear forgings for tractor PTO gearboxes, agricultural equipment drives, industrial reducers and marine gearboxes. We forge shaft gear geometries up to 600 mm overall length with gear flange OD to 400 mm.
EN36 (SAE 8617 equivalent) is the preferred grade for case-hardened gears requiring a tough, ductile core with a hard carburised shell of 58–62 HRC. Ideal for spur and helical gears in automotive gearboxes, industrial reducers and wind turbine planetary stages. Case depth typically 0.8–2.0 mm depending on module and application. Supplied normalised for machinability prior to gear cutting.
SAE 8620 (EN362 equivalent) is widely specified by automotive and gearbox OEMs for carburised and case-hardened gears. Low alloy content keeps material cost controlled while the nickel-chromium-molybdenum combination delivers the hardenability needed for section sizes up to 80 mm. Shivam Forge supplies SAE 8620 gear blanks with chemistry certified against AISI limits.
EN19 (42CrMo4, AISI 4140 equivalent) is the standard for through-hardened industrial gears, pinions and shafts where the full cross-section must achieve 28–34 HRC. High hardenability, good machinability after annealing and excellent fatigue resistance make EN19 the dominant choice for industrial gearbox shafts, worm gears and large pinion shafts. We forge EN19 gear blanks up to 1000 mm OD.
EN24 (AISI 4340, 40NiCrMo6) delivers superior core strength and toughness compared to EN19, making it the choice for high-torque mining gearboxes, heavy-vehicle transfer cases, crane gearboxes and offshore drive systems where shock loading is severe. Through-hardened to 32–40 HRC or case-hardened for surface wear resistance. We forge EN24 ring and disc blanks up to 1200 mm OD.
All gear blanks are supplied in the annealed or normalised condition unless otherwise specified. Spheroidise annealing of EN36 and SAE 8620 to ≤207 HB ensures consistent machinability for gear hobbing and shaving operations. EN19 and EN24 are supplied normalised to 170–210 HB. Heat treatment records included with each consignment.
Near-net-shape forging with properly designed closed dies orients the metal grain flow to follow the tooth profile — the same direction as the maximum bending stress at the tooth root. This alignment increases tooth-bending fatigue life by 40–60% compared to blanks machined from rolled bar, where grain flow runs axially and is cut across at the tooth root.
Our gear blank tooling is designed to minimise hobbing allowance to 3–5 mm per side on the tooth profile diameter and 2–4 mm on the face width. Reduced allowance cuts gear hobbing cycle time, reduces cutting tool consumption and speeds the overall gear manufacturing lead time. For high-volume gear production, near-net-shape blanks can cut gear machining cost by 20–30%.
Shivam Forge supplies forged gear blanks to gearbox manufacturers for wind turbine drivetrains — planetary ring gear blanks in EN24, sun gear blanks in SAE 8620 and helical stage gear blanks in EN19. Wind turbine gearboxes demand ISO 6336 fatigue life certification and thorough dimensional traceability from forging through gear cutting and heat treatment.
Heavy-duty gear blanks for mine hoist gearboxes, mill drive gearboxes, conveyor drive reducers and construction equipment final drives. We supply EN24 (4340) blanks up to 1200 mm OD for large industrial ring gears, and EN19 pinion shaft blanks for mill drive applications. Material test reports, UT testing and NDT are available.
Each gear blank consignment ships with a dimensional inspection report, material test report (chemistry and mechanical properties), heat treatment record and forging grain flow certification on request. Our quality system is ISO 9001:2015 certified. First-off sample approval with CMM report available for new gear blank programmes.
Shivam Forge is a dedicated gear blank forging manufacturer based at Shapar GIDC, Rajkot, Gujarat, producing closed-die forged blanks for spur gears, helical gears, bevel gears, ring gears, planetary stages and sun gear sets. The fundamental metallurgical advantage of a forged gear blank over a blank machined from rolled bar stock lies in grain flow orientation: when die geometry is correctly designed, the metal grain aligns with the tooth profile, placing the strongest grain direction against the bending stress at the tooth root. Gear blanks machined from rolled bar have grain flow running perpendicular to the tooth root — essentially the weakest orientation for tooth-bending fatigue loading. Shivam Forge's near-net-shape die design ensures that grain flow follows the tooth contour, delivering a 40–60% improvement in tooth-bending fatigue life on case-hardened gears.
Material selection for gear blank forgings is driven by the hardening route and the gear's service duty. EN36 (20NiCrMo2) and SAE 8620 are the primary grades for carburised and case-hardened gears — the low carbon core retains toughness while the carburised case achieves 58–62 HRC for surface wear resistance. EN19 (42CrMo4, AISI 4140) is the standard for through-hardened industrial gears, offering the combination of high hardenability, good machinability and excellent fatigue resistance needed for industrial gearbox shafts, pinions and worm gears. EN24 (AISI 4340) is specified for the most demanding applications — mine hoist gearboxes, crane drive gearboxes, offshore winch drives — where high torque, shock loading and extended service intervals demand the highest core strength and toughness available in a Cr-Ni-Mo alloy steel.
The commercial case for near-net-shape gear blank forging versus bar stock machining becomes compelling above module 4 and OD 200 mm. At these dimensions, the weight of material machined away from a bar blank to produce the gear disc profile is significant — typically 30–50% of the input bar weight. Near-net-shape forging reduces this to 10–20%, and the hobbing allowance reduction from 15–25 mm per side (bar blank) to 3–5 mm per side (forged blank) directly reduces gear hobbing machine cycle time and cutter consumption. For wind turbine ring gears in the 800–1200 mm OD range, forging the ring profile near-net saves 200–400 kg of material per blank — a commercially significant figure at EN24 alloy steel prices.
Shivam Forge supplies forged gear blanks to gearbox OEMs across India's wind energy sector, mining equipment industry, industrial drive manufacturers, agricultural equipment makers and automotive transmission suppliers. Our quality documentation package for gear blanks includes a material test report (chemistry and mechanical properties to EN 10083, ISO 683 or AISI limits), dimensional inspection report, heat treatment record and — on request — forging grain flow macrostructure certificate. ISO 9001:2015 certification and 20+ years of forging experience underpin the consistency that gearbox OEMs and Tier 1 gear manufacturers need from a critical blank supplier.
To discuss forged gear blank requirements for your gearbox or gear manufacturing programme, contact Shivam Forge at +91 92657 72827 or sales@shivamforge.com. Provide your component drawing, grade specification, OD, bore and face dimensions, supply condition required and annual volume. We will confirm forging capability, advise on near-net-shape opportunities to reduce your machining cost and provide a competitive quotation with lead time within 48 hours.
We forge spur gear blanks, helical gear blanks, bevel gear blanks (straight and spiral), ring gear blanks, planetary gear blanks, sun gear blanks, cluster gear blanks and gear shaft blanks. OD range 50–1200 mm. All types can be supplied with or without a forged bore depending on the blank size and customer requirement.
Standard grades: EN36 (20NiCrMo2) and SAE 8620 for case-hardened gears; EN19 (42CrMo4, AISI 4140) for through-hardened industrial gears; EN24 (AISI 4340, 40NiCrMo6) for heavy-duty and high-impact gear applications. Other grades available on request — 20MnCr5, 16MnCr5, 18CrNiMo7-6 for carburising applications.
We produce gear blanks from 50 mm OD (small planetary gears) to 1200 mm OD (large ring gears and slewing ring blanks). Bore can be forged or left solid depending on OD and wall thickness. Weight range 0.5 kg to approximately 500 kg per blank.
Near-net-shape forging reduces the hobbing allowance to 3–5 mm per side on the pitch circle and 2–4 mm per face, compared to 15–25 mm typical of a blank machined from rolled bar. This cuts gear-hobbing machine cycle time, reduces carbide cutter consumption and reduces coolant usage. On high-volume automotive gear programmes, the saving in machining cost typically exceeds the forging premium over bar stock.
Yes. We provide forging grain flow macrostructure certificates — sectioned and etched samples showing grain flow orientation relative to the tooth profile — on request for new part qualification. This is standard practice for wind energy and aerospace gear programmes. Grain flow reports are available as part of the first-article inspection (FAI) package.
Standard supply: annealed (EN36, SAE 8620) to ≤207 HB or normalised (EN19, EN24) to 170–210 HB for machinability. We can also supply normalised-and-tempered for improved machinability, or in the rough-forged condition if the customer performs their own heat treatment. Specify your required condition in the enquiry.
Yes. We supply ring gear blanks in EN24 (4340) and sun/planet gear blanks in SAE 8620 and EN19 for wind turbine planetary gearboxes. UT testing, full material traceability, chemistry and mechanical property certification, and grain flow reports are available to meet wind energy gearbox OEM qualification requirements.
Send your gear blank drawing or sketch, grade specification, OD/bore/face width, quantity and required condition to sales@shivamforge.com or call +91 92657 72827. We will review your drawings, confirm forging capability and provide a quotation with lead time within 48 hours.
Why Choose Shivam Forge
Shivam Forge delivers precision hot-forged components from our integrated Shapar, Rajkot facility — covering forging, CNC machining, heat treatment, and quality inspection under one roof.
