Safety-Critical Forged Stub Axles for Automotive & Agricultural Vehicles
Shivam Forge manufactures hot-drop forged stub axles for passenger cars, LCVs, tractors, agricultural trailers, and three-wheelers at our Shapar GIDC facility in Rajkot. Produced in EN19T (42CrMo4) and EN24T for safety-critical steering duty, our stub axle forgings are 100% magnetic particle inspected, CNC-machined to drawing, and supplied with PPAP Level 3 documentation for OEM customers.
The stub axle is one of the most critically loaded components in any road vehicle's steering system. It carries the full weight of the corner of the vehicle as a bending load, transmits braking forces through the hub, and takes the castor and camber side loads from steering. A casting or machined bar would crack. A hot forging, with grain flow aligned to the load path through the flange radius and spindle axis, survives the fatigue life required by automotive OEMs. Shivam Forge has produced stub axle forgings for Indian and export OEMs for over two decades — the dimensional tolerances, material discipline, and PPAP documentation that automotive procurement teams require are standard practice for our team.
Front stub axles for hatchbacks, sedans, and SUVs in EN19T (42CrMo4T) or EN24T depending on vehicle weight class. Hub flange bolt pattern, bearing seat diameter, and thread form to OEM drawing. Supplied as CNC-machined complete or as semi-finished forging for final OEM machining.
Light commercial vehicle stub axles for mini trucks, pick-ups, and delivery vans — heavier section than passenger car, often in EN24T or SAE 4340 for higher load rating. Bearing seat machined to k6 tolerance, brake drum register faced, king pin bore reamed to H7 where applicable.
Front stub axles for two-wheel drive and four-wheel drive tractors in EN19T or EN24T. Agricultural tractors subject the stub axle to high bending loads from field surface irregularities at low speed — our forgings are designed with generous fillet radii at the flange–spindle intersection to resist fatigue cracking at this stress concentration.
Economy-grade stub axles for agricultural trailers and trolleys in EN8 (C45) or EN19 normalised condition. Lower cost than automotive grade but still hot-drop forged for grain flow continuity. Bearing seat machined to drawing, thread form as specified. Available in standard section sizes for trailer axle manufacturers.
Stub axles for three-wheelers (auto-rickshaws, cargo three-wheelers) and quadricycles in EN8 or EN19 grade. Compact flange design with single-row bearing seat and thread for castle nut retention. Forging weight 0.8–2.5 kg typical. Supplied to three-wheeler axle OEMs in the Rajkot–Gujarat region.
Off-highway applications — tracked loaders, compact excavators, telehandlers, forklifts — sometimes use stub axle configurations for steered non-driven front wheels. We forge custom stub axles to customer drawings in EN24T or SAE 4340, with full CNC machining to finished dimension including king pin bore and bearing seats.
Our in-house tool room designs closed dies using forging simulation software to verify material fill, flash distribution, and fibre flow direction. The flange–spindle intersection is the fatigue-critical zone — die design ensures grain flow is continuous and aligned with the load path at this feature.
Stub axle blanks are heated in a natural gas rotary furnace to 1150–1250°C and forged in closed dies on 250T to 800T hydraulic or friction screw presses depending on forging weight. Multi-blow forging sequence ensures complete die fill and accurate flash formation without cold shuts or laps.
After forging and trimming, stub axles are normalised at 860–900°C to refine grain structure. For EN19T and EN24T grades, quench and temper is applied to achieve specified mechanical properties: tensile strength 850–1000 MPa, yield strength 680–800 MPa, elongation >12%. Heat treatment records maintained for every lot.
Post-heat-treatment, stub axles go to our CNC turning centre for bearing seat machining (k6/m6 tolerance, Ra 0.8 μm), hub flange facing, brake register turning, thread cutting (M and UNF profiles), and king pin bore reaming to H7. We machine from the forged blank — no bar stock waste, full grain flow preserved.
Every finished stub axle is magnetic particle inspected under wet fluorescent MT per ASTM E1444 or equivalent. The flange–spindle fillet and king pin bore area receive enhanced scrutiny. Any indications — linear or circular — are cause for rejection. Inspection records retained for PPAP documentation.
We generate full PPAP Level 3 documentation for automotive OEM customers: Part Submission Warrant, dimensional measurement results, material test certificate, process flow diagram, PFMEA, control plan, and measurement system analysis (MSA). Cpk studies for critical dimensions on request.
EN19T (709M40T, equivalent to 42CrMo4T per EN 10083) is the most widely used grade for automotive stub axles in India. Quenched and tempered to 850–1000 MPa UTS, 680–800 MPa yield, 12% elongation minimum. Excellent machinability in the Q&T condition. Hardness 248–302 HB after Q&T.
EN24T (817M40T, equivalent to 817M40 per BS 970 or 4340 per SAE) for heavier LCVs and stub axles requiring UTS above 1000 MPa. Nickel-chromium-molybdenum alloy content provides superior hardenability for large-section stub axles. Typical Q&T properties: 1000–1200 MPa UTS, >900 MPa yield.
EN8 (080M40) or C45 medium carbon steel for agricultural trailer and light-duty stub axles where high-tensile alloy steel is overspecified. Normalised or induction-hardened bearing seat. Significantly lower material cost than EN19/EN24 — suitable where load ratings permit and fatigue life requirements are less demanding.
708M40 (a chromium-molybdenum grade equivalent to SAE 4130) is occasionally specified by Indian commercial vehicle OEMs for medium-duty stub axles. We produce this grade with full composition verification and mechanical property certification per BS 970 requirements.
Bearing seats and thread roots can be induction hardened to 55–60 HRC surface hardness with 1.0–2.0 mm case depth after final machining. Case carburising of EN36 grade provides an alternative for OEMs specifying high surface hardness with tough core — applicable to niche stub axle designs.
Finished stub axles can be supplied with zinc electroplating (8–15 μm bright or yellow chromate) for corrosion protection during storage and transport, or black oxide treatment for mild corrosion resistance. Agricultural and aftermarket customers typically specify black oxide; automotive OEM customers usually manage surface treatment in-house.
The stub axle is a safety-critical component. It is the spindle on which the front wheel bearing sits, the structure through which braking torque is transmitted to the vehicle chassis, and the pivot axis about which steering geometry is defined. An in-service failure — a fatigue crack propagating through the spindle at the flange radius — removes the wheel from the vehicle. This is why every legitimate automotive specification calls for hot-drop forged stub axles, not cast iron, not machined bar. The forging process aligns grain flow along the spindle axis and around the flange radius, exactly where bending and torsional fatigue stresses are highest.
Shivam Forge at Shapar GIDC, Rajkot has manufactured stub axle forgings for Indian automotive OEMs and their tier suppliers for over 20 years. Our press shop runs 250T to 800T presses, capable of forging stub axles from the smallest three-wheeler stub (0.8 kg) to the heaviest truck LCV stub (6–8 kg). Our in-house tool room designs and machines the closed dies, and our CNC turning department finishes the bearing seats, flanges, and thread forms. The entire process from billet to inspected, PPAP-documented stub axle happens under one roof at Shapar — no subcontractors, no traceability gaps.
Grade selection for stub axles depends on the vehicle's load rating and the OEM's engineering specification. EN19T (42CrMo4T, equivalent to SAE 4140 Q&T) is the most common choice for passenger car and light LCV applications — it machines cleanly after quench and temper, achieves 248–302 HB in the right section sizes, and is cost-effective in the Indian market. EN24T (817M40T, equivalent to SAE 4340) is reserved for heavier applications where tensile strength above 1000 MPa is required. EN8 (C45) serves agricultural trailer stub axles where load requirements are lower and initial price is the primary driver. We will advise on grade selection if you share your vehicle weight and application data.
Our inspection regime for stub axles is non-negotiable: every piece is 100% magnetic particle inspected under wet fluorescent conditions per ASTM E1444. The flange–spindle fillet radius is the fatigue stress concentration that ultimately determines service life — any linear indication at this feature is cause for rejection, not re-inspection. We retain MT records for each lot. For automotive OEM PPAP submission, we generate Part Submission Warrants, dimensional studies from our Zeiss CMM, PFMEA, control plans, and Cpk studies for critical dimensions. Level 3 PPAP is standard; Level 4 or 5 can be discussed for specific OEM requirements.
If you are a procurement engineer or product engineer looking for stub axle forging supply, Shivam Forge is a straightforward choice. We supply passenger car, LCV, tractor, trailer, and three-wheeler stub axles from our Rajkot facility with short lead times on standard profiles. New profile tooling takes 5–6 weeks. PPAP documentation is included for OEM customers. Our price is typically 20–30% below comparable Mumbai or Pune vendors for Gujarat-based customers, and competitive against any India source for out-of-state buyers. Call +91-9265772827 or email info@shivamforge.com with your drawing and we will come back within 48 hours.
Yes. We manufacture hot-drop forged stub axles at Shapar GIDC, Rajkot for passenger cars, LCVs, tractors, agricultural trailers, and three-wheelers. Grades: EN19T, EN24T, EN8, and 708M40. Machined to customer drawing with 100% MT inspection.
EN19T (42CrMo4T) suits most passenger car and light LCV stub axles — 850–1000 MPa UTS is sufficient for typical loads, and the material is cost-effective. EN24T is used for heavier LCVs and applications requiring UTS above 1000 MPa. Our engineers will recommend the grade based on your vehicle weight and load specification.
Yes. We supply PPAP Level 1 through Level 3 documentation: Part Submission Warrant, dimensional results, material certificate, process flow, PFMEA, control plan, and MSA. Cpk studies for critical dimensions (bearing seat OD, flange face runout) available on request.
On CNC-machined stub axles: bearing seat diameter to k6 tolerance (±0.008–0.012 mm on typical sizes), bearing seat Ra 0.8 μm, thread major diameter to 6g tolerance, king pin bore to H7. Forging-only supply: ±1.0–1.5 mm on major dimensions per IS 3469 die forging tolerances.
Yes. Every stub axle we ship is 100% magnetic particle inspected under wet fluorescent MT per ASTM E1444. The flange–spindle fillet — the primary fatigue initiation zone — receives enhanced inspection. MT records are retained and available as part of PPAP documentation.
For new tooling (new die), minimum 200–500 pieces to amortise die cost. For standard profiles already in our die library, minimum order is 50 pieces. For prototype or pre-production samples, we can supply 5–20 pieces with single-cavity tooling at higher per-piece cost.
For standard profiles with existing tooling: 7–10 working days. For new profiles requiring die manufacture: 5–6 weeks for tooling (die design + machining + first article) plus 2 weeks production. PPAP documentation adds 1–2 weeks if dimensional studies are required.
Send your drawing with material grade, heat treatment specification, required tolerances, and annual volume to info@shivamforge.com or call +91-9265772827. We will respond with a detailed quote including tooling cost, piece price, and PPAP documentation cost 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.
