STRUCTURES THAT
SUPPORT THE JOURNEY.
From high-volume three-passenger bus seat frames to automotive body chassis members and heavy-gauge stamped brackets, Sri Balaji Gears engineers welded assemblies built for exceptional durability and passenger safety.
ENGINEERED SOLUTIONS BY CATEGORY.
Click tabs below to inspect specifications and fabrication parameters for each product category.
Three-Seat Bus Seating Assembly
Our flagship high-volume seating frame assembly designed for state transport corporations and private coach builders via Tier-1 seating suppliers like UNO MINDA.
- Structural Frame: Cold-drawn ERW steel tubes (Ø25.4mm & Ø31.8mm) with 1.6mm – 2.0mm wall thickness.
- Floor Mount Gussets: 3.0mm – 4.0mm high-tensile anchor plates with pre-drilled M10/M12 chassis bolt slots.
- Welding Execution: Continuous robotic GMAW fillet welds at all primary tubular intersections.
- Safety Compliance: Meets Indian AIS 023 seat anchor and dynamic passenger load specifications.
Two-Seat Luxury Passenger Frames
Engineered for intercity luxury coaches and staff transport buses, incorporating integrated brackets for mechanical recliners, adjustable footrests, and reinforced grab handles.
- Ergonomic Contour: Multi-radius CNC pipe bends delivering anatomical lumbar support.
- Reclining Mechanism Mounts: Laser-pierced bracket mounts aligned for seamless mechanical actuator fitment.
- Armrest & Seat Belt Fixations: Built-in 2-point and 3-point seatbelt anchoring gussets tested for pull strength.
- Vibration Dampening: Rigid triangulated crossbars prevent harmonic road flutter.
Auto Body Chassis Tubular Frame Parts
Tubular subframes, cross-members, engine mount cradles, and suspension gusset brackets manufactured for major OEMs including TVS Motor Company.
- Torsional Rigidity: Engineered for high dynamic shock absorption and cyclic fatigue endurance.
- Fixture Precision: 100% pneumatic clamped jig welding guarantees coordinate repeatability < 0.5mm.
- Deep Penetration Welds: Macro-etched weld joints guaranteeing complete root fusion and zero lack-of-fusion voids.
- Direct Line-Side Ready: Fully pre-treated, primed, or powder-coated for immediate assembly line integration.
AUTO CHASSIS WELDING
Pressed Brackets & Heavy Stampings
Precision pressed automotive stampings, suspension reinforcements, floor anchor gussets, and battery tray supports produced on our mechanical and hydraulic press fleet.
- Thickness Range: Sheet metal blanking and forming from 1.2mm up to 6.0mm high-tensile steel.
- In-House Tool Maintenance: Tool room technicians maintaining progressive dies with quick changeovers.
- Burr-Free Finishes: Edge chamfering and deburring to eliminate sharp edges prior to welding or coating.
- High Repeatability: Batch-to-batch dimensional stability verified on coordinate checking fixtures.
PRESSED COMPONENTS
TECHNICAL SPECIFICATIONS
FOR SEATING & CHASSIS FRAMES.
Detailed metallurgical and process parameters adhered to across our production lines.
| Technical Parameter | Standard Specification | Testing & Compliance Protocol |
|---|---|---|
| Tubular Raw Material | ERW Steel Tubes (IS 2062 Grade A/B / BS 6323 Part 5) | Spectrochemical & Tensile Verification |
| Tube Diameter & Wall | Ø22.0mm to Ø50.8mm (Thickness 1.6mm – 3.2mm) | Ultrasonic & Vernier Caliper Inspection |
| Sheet Metal Components | CRCA Steel (IS 513 EDD / HR Steel IS 1079) | Hardness & Erichsen Cupping Test |
| Welding Process | GMAW / MIG (80% Ar / 20% CO₂ Shielding Gas) | AWS D1.1 & D1.3 Code Compliance |
| Weld Bead Integrity | Throat thickness > 3.5mm, zero spatter, no undercuts | Macro-etch Penetration & Dye-Pen (PT) |
| Corrosion Protection | 7-Tank Degreasing/Phosphate + Pure Polyester Powder | 500+ Hours ASTM B117 Salt Spray Test |
| Coating Thickness | 60 to 80 microns dry film thickness (DFT) | Electromagnetic DFT Gauge Verification |
| Seating Strength Standard | AIS 023 / AIS 052 Code of Practice | Static Passenger Shear & Anchorage Testing |