Forged Bevel Gear Blanks for Automotive Differentials, Tractor Axles & Industrial Gearboxes
Shivam Forge manufactures precision hot-forged bevel gear blanks — straight bevel gear blanks, spiral bevel gear blanks (ring and pinion), hypoid gear blanks, differential side gears and differential spider gears — at our Shapar GIDC facility in Rajkot, Gujarat. We work in EN36, EN19, SAE 8620 and SAE 4320 case-hardening and alloy steel grades, forged near-net to minimise hobbing and grinding stock.
Bevel gear manufacturing cost is dominated by the hobbing, lapping and grinding operations that produce the final tooth profile. Every millimetre of excess material on a forged blank adds machining time and tool wear. Shivam Forge produces bevel gear blanks forged close to the finished back cone diameter, pitch cone height and hub bore — leaving only the minimum grinding and hobbing stock. The result is a forged blank that reduces your gear machining cycle time by 20–35% compared to blanks machined from round bar.
Forged straight bevel gear blanks in EN19 and SAE 4140 for industrial gearboxes, hand tool drives and agricultural PTO applications. Pitch cone angle, back cone diameter and hub hub bore diameter are forged to drawing. Suitable for module 2–12 straight bevel gear cutting.
Forged spiral bevel ring gear blanks in EN36 and SAE 8620 for truck, bus and tractor differential ring gears. Large-diameter ring gear blanks forged as near-net annular profiles with integral mounting flange where required. Blank OD up to 500 mm, module 4–16.
Forged spiral bevel pinion blanks in EN36 and SAE 8620 as solid or hollow shaft-pinion forms. Shaft-pinion forgings have the gear blank and drive shaft forged integral — the most fatigue-resistant configuration for truck and tractor final drive pinions.
Forged hypoid ring and pinion blanks for passenger car and light truck rear axle differentials. Hypoid gear geometry places the pinion shaft axis below the ring gear centreline — the forging must maintain tight concentricity between the blank OD and bore to achieve correct gear contact after hobbing and lapping.
Forged differential side gear blanks in EN36 or SAE 8620 for automotive open and limited-slip differentials. The splined bore and back face of the side gear are forged near-net, with only the tooth profile and thrust surface requiring machining. Weight 0.3–3 kg.
Forged differential spider gear blanks in EN36 for 2-spider and 4-spider differential assemblies. Spherical seat and pin bore are forged near-net. Module 4–8, pitch cone angle 45°. Case hardened to 58–62 HRC at 0.8–1.2 mm depth after gear cutting.
Bevel gear blanks are forged in precision closed dies designed to hold the pitch cone height and back cone diameter to ±0.3 mm. Die design uses FEA-based metal flow simulation to ensure complete die fill at the tooth flank zone and hub bore without laps or underfill.
Case-hardening grades (EN36, SAE 8620, SAE 4320) are gas carburised at 920–940°C to achieve 0.8–1.2 mm case depth as measured by microhardness traverse. Surface carbon 0.8–1.0%. After carburising, gears are oil quenched to achieve 58–62 HRC surface hardness with a tough low-carbon core of 30–45 HRC.
All bevel gear blanks are supplied normalised at 870–900°C air cool unless the customer specifies annealed supply condition. Normalising gives a uniform pearlite-ferrite microstructure at 180–220 HB, which is the optimal machining condition for hobbing and turning operations.
Hub bore diameter, bore chamfers and back face perpendicularity are CNC machined in-house to provide a reliable datum for gear cutting operations. Hub bore is machined to H7 with Ra 1.6 μm. Back face is turned flat to ±0.05 mm. These machined datums eliminate set-up error on the gear cutting machine.
Forged bevel gear blanks for critical applications (truck differentials, aerospace gearboxes, marine drives) are ultrasonically tested to ASTM A388 to verify freedom from internal pipe, segregation or forging burst. UT records are included in the quality pack for critical orders.
Our bevel gear blanks are forged to minimum hobbing and grinding stock — typically 1.5–3 mm per tooth flank surface, versus 8–12 mm machining allowance on a turned-from-bar blank. This directly reduces your gear manufacturing cycle time, carbide tooling cost and coolant consumption.
In a correctly forged bevel gear blank, the fibrous grain flow runs from the root to the tip of each tooth, parallel to the tooth load direction. This gives the tooth root its maximum bending fatigue strength. In a machined-from-bar blank, the grain cuts across the teeth at the hub plane — a weaker configuration.
Shivam Forge has 20+ years of experience supplying forged bevel gear blanks to truck differential manufacturers, tractor axle gear suppliers and industrial gearbox manufacturers. We understand the tight dimensional requirements of gear blanks and the documentation needs of OEM procurement.
EN36 and SAE 8620 for case-hardened automotive and truck differential gears; EN19 and SAE 4140 for normalised or Q&T industrial gearbox gears; SAE 4320 for high-torque heavy truck final drive gears. We stock all these grades and can advise on grade selection.
We export bevel gear blanks to industrial gearbox manufacturers, marine drive suppliers and agricultural equipment companies in Europe, the Middle East and Southeast Asia. Export documentation includes EN10204 3.1 material certificates, UT reports and dimensional inspection records.
Forged bevel gear blanks from Shivam Forge are priced 25–40% below equivalent European supply. Indian gear blank forgings meet the same material and quality specifications — EN36, SAE 8620, 58–62 HRC case hardness — with full documentation at significantly lower cost.
Shivam Forge is a bevel gear forging manufacturer at Shapar GIDC, Rajkot, Gujarat, producing precision hot-forged bevel gear blanks for automotive differentials, tractor axles, industrial gearboxes and marine drives. Our product range covers straight bevel gear blanks, spiral bevel ring and pinion blanks, hypoid ring and pinion blanks, differential side gears and differential spider gears. We work in EN36, SAE 8620, SAE 4320 case-hardening grades and EN19, SAE 4140 alloy steel grades. All blanks are supplied normalised (180–220 HB) ready for gear cutting, or can be gas carburised to 58–62 HRC, 0.8–1.2 mm case depth after gear finishing.
The economics of near-net forging for bevel gear blanks are straightforward: gear hobbing and grinding are the most expensive operations in gear manufacturing, and every millimetre of excess blank material adds cycle time. A bevel gear blank forged to ±0.3 mm on the back cone diameter and pitch cone height has 1.5–3 mm of hobbing/grinding stock per flank, versus 8–12 mm on a turned-from-bar blank. At a typical hobbing rate of 3–5 mm per minute stock removal for medium-module gears, this difference translates to 15–25 minutes per blank saved in hobbing alone. For a production volume of 5,000 ring gears per month, that is a substantial machining cost reduction.
Grain flow in bevel gear blanks matters as much as it does in shafts and knuckles. In a forged bevel gear, the grain runs radially outward from the hub, following the back cone surface and reaching the tooth roots with continuous fibrous grain flow parallel to the bending load direction. This is the configuration that maximises tooth root bending fatigue strength — the primary failure mode for heavily loaded truck differential and tractor PTO gears. Machined-from-bar blanks have grain flow perpendicular to the tooth, crossing the tooth root at the worst possible angle for bending fatigue resistance.
Our Rajkot facility machines hub bores and back face datums in-house on CNC lathes before releasing blanks for gear cutting. Hub bores are machined to H7 (±0.015 mm on typical sizes) with Ra 1.6 μm. Back faces are turned flat to ±0.05 mm perpendicularity to the bore axis. These machined datums eliminate the set-up error that occurs when gear cutting machines use as-forged surfaces as datums — a common source of pitch error and runout in gear blanks sourced as raw forgings from manufacturers who do not machine in-house.
For gear manufacturers and OEM purchasing teams, Shivam Forge offers a complete bevel gear blank supply solution: forging in the correct grade, normalising or gas carburising heat treatment, CNC machining of datums and full quality documentation per ISO 9001:2015. We export to gear manufacturers in 12+ countries and supply Indian tractor, truck differential and industrial gearbox manufacturers from our Rajkot facility. Forged bevel gear blanks from Shivam Forge are typically 25–40% below European supply costs at the same quality level. Contact us at +91 92657 72827 or sales@shivamforge.com with your blank drawing and annual requirement.
We manufacture straight bevel gear blanks, spiral bevel ring gear blanks, spiral bevel pinion blanks, hypoid ring and pinion blanks, differential side gears and differential spider gears. We cover automotive differentials, tractor axles, industrial gearboxes and marine drives.
EN36 and SAE 8620 for case-hardened automotive and truck differential gears (58–62 HRC surface, 0.8–1.2 mm case depth). EN19/SAE 4140 for normalised or Q&T industrial gearbox bevel gears. SAE 4320 for high-torque heavy truck and off-highway final drive gears.
Price depends on gear blank OD, weight, steel grade and whether machining of hub bore and back face is required. As a guide, differential side gear blanks in SAE 8620 (normalised) start from ₹300–600 per piece at production volumes. Ring gear blanks for truck differentials are priced per kg of forging weight. Call +91 92657 72827 for a specific quotation.
Shivam Forge at Shapar GIDC, Rajkot is a leading forged bevel gear blank manufacturer in India with 20+ years of experience in automotive differential gears, tractor axle gears and industrial gearbox blanks. ISO 9001:2015 certified with in-house gas carburising and CNC machining.
Yes. We manufacture spiral bevel ring gear blanks (up to 500 mm OD) and shaft-pinion blanks in EN36 and SAE 8620 for truck differential applications. Blanks are supplied normalised (180–220 HB) ready for hobbing, or carburised and hardened to 58–62 HRC after gear cutting.
Our gas carburising specification achieves 0.8–1.2 mm effective case depth (measured at 550 HV) on EN36 and SAE 8620 bevel gears, with surface hardness of 58–62 HRC and surface carbon of 0.8–1.0%. Case depth is verified by microhardness traverse on a sample coupon from each furnace load.
For existing die profiles, the minimum order is 50 pieces. New die development requires an initial order of 100–500 pieces depending on die cost amortisation. Prototype runs of 10–25 pieces are available for development projects with full inspection reports.
Send your gear blank drawing (showing pitch cone, back cone, hub bore, module and tooth count) along with material grade, heat treatment specification and required quantity to sales@shivamforge.com or call +91 92657 72827. We will respond with a quotation and lead time within 24 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.
