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Girgaon, Mumbai - 400004
Hollow Bar Manufacturer & Exporter in India
Trusted Global Supplier & Exporters of Hollow Bar
Kamal Steels is a leading Hollow Bar Manufacturer in India, specializing in the production of high-quality hollow bars for engineering, machining, hydraulic and structural applications. Since 1984, we have been manufacturing precision hollow bars that meet the demanding requirements of domestic and international industries.
As an experienced Hollow Bar Exporter, we supply premium-quality hollow bars to customers across global markets with export-grade packaging, complete documentation and reliable delivery schedules. Our products are widely accepted for their dimensional accuracy, strength, machinability and consistent performance.
We manufacture hollow bars in various materials, sizes, wall thicknesses and specifications to support a wide range of industrial applications. Our hollow bars are extensively used in hydraulic cylinders, machine components, automotive parts, construction equipment, oil & gas systems and heavy engineering projects.
All hollow bars are produced using high-grade raw materials and advanced manufacturing processes in accordance with international ASTM and ASME standards. This ensures superior mechanical properties, excellent structural integrity and long service life even under demanding operating conditions.
Every hollow bar undergoes strict quality control procedures including dimensional inspection, material verification and performance testing before dispatch. With decades of manufacturing expertise and a strong export network, Kamal Steels continues to be a trusted source for high-performance hollow bars worldwide.
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Certifications & Compliance
- ISO 9001:2015 Certified
- ISO 14001 Certified
- ISO 45001 Certified
- PED Approved Materials
- MSME Registered Company
- IEC Export Certification
- GST Registered Business
Hollow Bar Specifications
| Specification | Details |
|---|---|
| Product Name | Hollow Bar |
| Materials | Carbon Steel, Alloy Steel, Stainless Steel |
| Type | Seamless / Machined Hollow Bar |
| Size Range | 20 mm to 500 mm |
| Wall Thickness | As per requirement / Customized |
| Length | Single Random / Double Random / Cut Length |
| Standards | ASTM A511, ASTM A519, EN 10294 |
| End Finish | Plain End, Beveled End, Machined End |
Hollow Bar Weight Chart
The following table provides the approximate weight of stainless steel hollow bars based on standard outside diameter (OD) and inside diameter (ID). Actual weight may vary depending on the material grade, manufacturing process, dimensional tolerances, and applicable ASTM/ASME specifications.
| Outside Diameter (mm) | Inside Diameter (mm) | Wall Thickness (mm) | Approx. Weight (kg/m) |
|---|---|---|---|
| 25 | 15 | 5 | 2.46 |
| 30 | 20 | 5 | 3.08 |
| 40 | 25 | 7.5 | 6.02 |
| 50 | 30 | 10 | 9.86 |
| 60 | 40 | 10 | 12.34 |
| 75 | 50 | 12.5 | 19.25 |
| 90 | 60 | 15 | 27.12 |
| 100 | 70 | 15 | 31.07 |
| 125 | 85 | 20 | 48.67 |
| 150 | 100 | 25 | 69.41 |
| 175 | 125 | 25 | 83.96 |
| 200 | 150 | 25 | 98.52 |
Note: The above weights are approximate for stainless steel hollow bars. Actual weight depends on the material grade (SS 304, SS 316, Duplex, Super Duplex, Alloy Steel, etc.), outside diameter, inside diameter, manufacturing tolerances, and applicable ASTM/ASME standards.
Hollow Bar Size Chart & Dimensions
Hollow bars are available in a wide range of sizes and wall thicknesses suitable for hydraulic, machining and engineering applications.
| Outer Diameter (OD) | Bore (ID) | Wall Thickness | Weight (Approx.) |
|---|---|---|---|
| 30 mm | 10 mm | 10 mm | — |
| 50 mm | 20 mm | 15 mm | — |
| 80 mm | 40 mm | 20 mm | — |
| 120 mm | 60 mm | 30 mm | — |
| 200 mm | 100 mm | 50 mm | — |
Types of Hollow Bars
- Seamless Hollow Bars
- Welded Hollow Bars
- Precision Machined Hollow Bars
Hollow Bar Equivalent Grades
| Material | UNS Number | Werkstoff No. |
|---|---|---|
| Carbon Steel Hollow Bar | A105 | 1.0460 |
| Stainless Steel Hollow Bar 304 | S30400 | 1.4301 |
| Stainless Steel Hollow Bar 316 | S31600 | 1.4401 |
Hollow Bar Manufacturing Process
Hollow Bars are manufactured using high-quality raw materials and advanced production techniques to achieve excellent dimensional accuracy, structural integrity and machining performance. The manufacturing process is carefully controlled to ensure consistent quality and compliance with international standards.
- Raw Material Selection: Premium quality steel billets or alloy materials are selected and tested for chemical composition and mechanical properties.
- Hot Rolling or Piercing: The raw material is heated and processed through hot rolling or rotary piercing methods to create the hollow center.
- Sizing & Shaping: Hollow bars are formed to the required outside diameter, bore size and wall thickness according to customer specifications.
- Heat Treatment: Controlled heat treatment processes are performed to improve strength, toughness, machinability and overall mechanical properties.
- Straightening Process: The bars are straightened to ensure dimensional accuracy and uniformity throughout the entire length.
- Machining & Finishing: Surface finishing and precision machining are carried out when tighter tolerances or specific finishes are required.
- Testing & Inspection: Ultrasonic testing, dimensional inspection, hardness testing and visual inspection are performed to verify product quality.
- Marking & Packaging: Finished hollow bars are marked, packed and prepared for safe domestic and international shipment.
The finished Hollow Bars provide excellent machinability, high strength, dimensional consistency and reliable performance for hydraulic cylinders, engineering components, automotive parts, oil & gas equipment and heavy industrial applications.
Request a QuoteHollow Bar vs Solid Bar Comparison
Both Hollow Bars and Solid Bars are widely used in engineering and manufacturing applications. However, Hollow Bars offer significant advantages in machining efficiency, weight reduction and material utilization, making them a preferred choice for many industrial applications.
| Property | Hollow Bar | Solid Bar |
|---|---|---|
| Material Usage | Optimized material consumption | Higher material consumption |
| Machining Time | Reduced machining time | Longer machining time |
| Material Wastage | Minimal waste generation | Higher waste generation |
| Weight | Lighter for similar applications | Heavier |
| Production Cost | More cost-effective | Higher machining cost |
| Hydraulic Cylinder Use | Highly suitable | Requires extensive boring |
| Machinability | Excellent | Good |
| Structural Strength | High | Very High |
Hollow Bars are generally preferred for hydraulic cylinders, mechanical components, bushings, sleeves and precision-machined parts because they significantly reduce machining operations and material waste. Solid Bars are typically selected when a completely solid cross-section is required for maximum load-bearing capacity.
Chemical Composition of Hollow Bar
| Grade | Carbon (C) | Manganese (Mn) | Chromium (Cr) | Other Elements |
|---|---|---|---|---|
| Carbon Steel | 0.15 – 0.45 | 0.30 – 1.00 | — | Fe Balance |
| Alloy Steel | 0.20 – 0.50 | 0.50 – 1.20 | 0.40 – 2.00 | Mo, Ni, Fe Controlled |
| Stainless Steel | ≤ 0.08 | ≤ 2.00 | 10.5 – 18.0 | Ni, Mo, Fe Balanced |
Hollow Bar Standards
| ASTM Standards | EN Standards |
|---|---|
| ASTM A511 | EN 10294 |
| ASTM A519 | EN 10297 |
Mechanical Properties of Hollow Bar
Tensile Strength
Hollow bars provide high tensile strength suitable for heavy-duty machining and structural applications.
Yield Strength
They offer excellent yield strength ensuring stability under load and pressure conditions.
Elongation
Good elongation ensures ductility and ease of machining into complex components.
| Material | Tensile Strength (MPa, Min) | Yield Strength (MPa, Min) | Elongation (% Min) |
|---|---|---|---|
| Carbon Steel | 400 – 600 | 250 – 350 | 15% |
| Alloy Steel | 600 – 900 | 350 – 600 | 12% |
| Stainless Steel | 520 – 750 | 205 – 450 | 40% |
Features of Hollow Bar
- High Strength and Rigidity: Hollow bars offer excellent mechanical strength and rigidity, making them suitable for heavy-duty machining and structural applications.
- Weight Reduction Advantage: Due to their hollow design, they reduce overall component weight without compromising strength.
- Excellent Machinability: Hollow bars are easy to machine into precise components, reducing material wastage and production time.
- Uniform Material Quality: Manufactured with consistent wall thickness and material integrity for reliable performance.
- High Pressure Resistance: Suitable for hydraulic and mechanical applications requiring pressure-bearing capability.
- Good Corrosion Resistance: Depending on material grade, hollow bars offer resistance against corrosion in industrial environments.
- Reduced Material Wastage: Ideal for deep machining applications, minimizing scrap generation.
- Long Service Life: Designed for durability and consistent performance in demanding industrial applications.
Applications of Hollow Bar
Hollow bars are widely used in engineering and industrial applications where high strength, precision machining and weight optimization are required.
Hydraulic Systems
Used in hydraulic cylinders and systems requiring pressure resistance and precision performance.
Heavy Engineering
Ideal for manufacturing heavy-duty mechanical components and structural parts.
Automotive Industry
Used in automotive components requiring strength, accuracy and reduced weight.
Machine Tools
Widely used in machine tool manufacturing for precision-engineered parts.
Engineering Components
Suitable for shafts, bushings and other machined engineering components.
Oil & Gas Industry
Used in high-pressure and demanding environments in oil and gas operations.
Aerospace Industry
Applied in aerospace structures where lightweight and strength are critical.
Fabrication Industry
Used in fabrication projects requiring easy machining and structural reliability.
Industries We Serve
Kamal Steels supplies hollow bars to industries requiring precision, strength, reduced weight and high machining efficiency.
Hydraulic Industry
Widely used in hydraulic cylinders and fluid power systems.
Engineering Industry
Used in general and heavy engineering applications for machined components.
Automotive Industry
Applied in vehicle components requiring strength and weight optimization.
Manufacturing Industry
Used in production of precision-machined industrial parts.
Oil & Gas Industry
Suitable for high-pressure and demanding operational environments.
Aerospace Industry
Used in aerospace systems requiring high strength-to-weight ratio.
Fabrication Industry
Ideal for structural fabrication and custom engineering solutions.
Machine Tool Industry
Used in machine tool components and precision equipment manufacturing.
Packaging, Testing & Inspection
Packaging
- Wooden Box Packing: Hollow bars are securely packed in wooden boxes for safe export and transportation.
- Bundle Packing: Bars are bundled properly to ensure safe handling and storage.
- Protective Wrapping: Surface protection is provided to avoid scratches and damage.
- Export Standard Packaging: Packaging is done as per international export guidelines for global delivery.
Testing & Inspection
- Ultrasonic Testing: Detects internal defects and ensures material integrity.
- Dimensional Inspection: Ensures accurate size, wall thickness and tolerance compliance.
- Hardness Testing: Verifies mechanical strength and material grade.
- Hydrostatic Testing: Confirms pressure-bearing capability where applicable.
- Visual Inspection: Ensures surface finish and overall product quality.
- Third Party Inspection: Independent agencies verify quality standards and compliance.
Frequently Asked Questions
A Hollow Bar is a cylindrical metal bar with a concentric bore running through its center. It is widely used in machining, hydraulic cylinders and engineering applications where reduced machining time and material savings are important.
A Hollow Bar contains a pre-formed internal bore, while a Solid Bar is completely solid throughout. Hollow Bars reduce machining requirements, lower material wastage and decrease overall component weight compared to solid bars.
Hollow Bars are commonly available in Carbon Steel, Alloy Steel, Stainless Steel and other specialty grades depending on application requirements, strength requirements and operating conditions.
Hollow Bars are generally available in sizes ranging from 20 mm to 500 mm outer diameter, with various bore sizes, wall thicknesses and custom lengths available upon request.
Yes, Hollow Bars are widely used in hydraulic cylinder manufacturing because they provide excellent dimensional accuracy, strength, pressure resistance and reduced machining time.
Hollow Bars offer lower machining costs, reduced material wastage, lighter component weight, improved production efficiency and excellent mechanical performance for engineering applications.
Yes, Stainless Steel Hollow Bars are available in grades such as 304, 304L, 316 and 316L. They provide excellent corrosion resistance and are widely used in marine, chemical and industrial environments.
Hollow Bars are commonly manufactured according to ASTM A511, ASTM A519, EN 10294, EN 10297 and other international standards depending on the material grade and application requirements.
Hollow Bar weight is calculated using the outer diameter, inner diameter, length and material density. Weight calculators are commonly used to estimate the exact weight for procurement and engineering purposes.
You can contact Kamal Steels for the latest Hollow Bar price based on material grade, size, wall thickness, quantity and delivery location. Our team provides quick quotations and stock availability information.