Hollow Bar Manufacturer, Stockist & Exporter in India

Hollow Bar Manufacturer, Stockist & Exporter in India – Exotic Metals LLP

Introduction: Efficiency through Hollow Geometry

At Exotic Metals LLP our Hollow Bars represent a revolution in machining efficiency and material conservation. Unlike solid round bars that require extensive core drilling, a hollow bar is produced with a pre-existing central bore. This "near-net-shape" geometry allows manufacturers to bypass the most time-consuming and tool-intensive stage of production boring out the center.

Hollow Bar Manufacturer & Supplier in India

Our hollow bars are engineered for high-performance mechanical applications where weight reduction and structural integrity are equally critical. By utilizing advanced centrifugal casting or hot-piercing extrusion methods, we ensure that the concentricity and wall thickness of our bars are maintained to the tightest tolerances. As a leading manufacturer and exporter in India, Exotic Metals LLP provides hollow sections that serve as the primary raw material for bushings, cylinders, bearings, and high-pressure fluid connectors across the aerospace, petrochemical, and automotive sectors.

Technical Specification Table

Feature	Details
Outside Diameter (OD)	32mm to 610mm (1.25” to 24”)
Wall Thickness	5mm to 100mm+
Standard Specifications	ASTM A511 (Stainless), ASTM A519 (Carbon), EN 10294-1
Length	3 to 7 Meters, Custom Cut-to-Size
Condition	Hot Finished, Cold Drawn, Annealed, Solution Annealed
Surface Finish	Pickled, Polished, Ground, or As-Rolled
Concentricity	Within 5% to 10% of the wall thickness

Key Types of Hollow Bars

Exotic Metals LLP offers several varieties of hollow sections, each tailored to specific fabrication and environmental requirements:

Stainless Steel Hollow Bars

Primarily used in corrosive environments, these bars (such as Grade 316L) are the gold standard for the chemical and food processing industries. They offer excellent weldability and are ideal for manufacturing pump housings and sanitary fittings
Mechanical Hollow Bars

Produced under the ASTM A519 or EN 10294-1 standards, these are engineered for structural and mechanical use. They are heat-treated to achieve specific hardness levels, making them perfect for hydraulic cylinders, rollers, and axles.
Centrifugally Cast Hollow Bars

For large-diameter requirements with thick walls, we utilize centrifugal casting. This process involves pouring molten metal into a rotating mold, which forces impurities to the inner surface (later machined away), resulting in a bar with an exceptionally dense and defect-free outer structure.
Cold Drawn Precision Hollow Bars

When the application demands high dimensional accuracy and a superior surface finish, we provide cold-drawn variants. The drawing process refines the grain structure and hardens the material, making it suitable for high-speed rotating components.
Duplex & Super Duplex Hollow Bars

For offshore and marine applications, we stock "Exotic" grades like 2205 and 2507 in hollow form. These provide the highest strength-to-weight ratio and are essential for subsea equipment and desalination plant manifolds.

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Material Grade Range

We stock and manufacture Hollow Bars in a comprehensive array of high-performance alloys:

Stainless Steel: 304, 304L, 316, 316L, 316Ti, 317L, 321, 310S, 347, 410, 420, 904L.
Duplex & Super Duplex: UNS S31803, S32205, S32750, S32760.
Nickel Alloys: Inconel 600, 625, Monel 400, K500, Hastelloy C276, Alloy 20.
Carbon Steel: ST52, E355, AISI 1018, 1026, 1045.
Alloy Steel: 4130, 4140, 4340, EN19, EN24.

Chemical Composition (%)

Our hollow bars are verified for chemical purity to ensure consistent performance.

Grade	Carbon (C)	Chromium (Cr)	Nickel (Ni)	Molybdenum (Mo)	Others
SS 304L	0.03 Max	18.0–20.0	8.0–11.0	—	Mn: 2.0
SS 316L	0.03 Max	16.0–18.0	10.0–14.0	2.0–3.0	N: 0.10
Duplex 2205	0.03 Max	22.0–23.0	4.5–6.5	3.0–3.5	N: 0.14–0.2
ST52.3	0.22 Max	—	—	—	Si: 0.55

Mechanical Properties

Ensuring maximum structural efficiency.

Grade	Tensile (MPa)	Yield (MPa)	Elongation (%)	Hardness (HB)
SS 304	515 Min	205 Min	40%	201 Max
SS 316L	485 Min	170 Min	40%	217 Max
E355 (ST52)	540–640	355 Min	20%	180–220
Alloy 625	827 Min	414 Min	30%	220 Max

Standard Weight Chart (Theoretical)

Formula: $(OD - WT) \times WT \times 0.02466 = Weight (kg/m)$ (for Carbon Steel).

OD (mm)	Wall (mm)	ID (mm)	Weight (kg/m)	Material Saved vs Solid
50 mm	10 mm	30 mm	9.86	~36%
80 mm	15 mm	50 mm	24.04	~39%
100 mm	20 mm	60 mm	39.46	~36%
150 mm	25 mm	100 mm	77.06	~44%
200 mm	30 mm	140 mm	125.77	~49%
300 mm	50 mm	200 mm	308.26	~44%

Delivery & Packaging Information

Exotic Metals LLP prioritizes the protection of the internal and external surfaces of our hollow bars:

Internal Protection: The ID of the bar is treated with a light rust-preventative coating and can be fitted with plastic end caps to prevent debris entry.
Surface Guard: For precision ground or cold-drawn hollow bars, we provide individual LDPE wrapping or PVC sleeves to maintain the surface finish.
Secure Logistics: Bars are bundled with heavy-duty steel strapping. For international exports, we utilize heat-treated wooden crates or "U" shaped steel cradles for safe maritime transit.
Traceability: Every bar is marked with its Heat Number, Size (OD x ID), Grade.
Compliance: All shipments include a Mill Test Certificate (MTC) as per EN 10204 3.1, along with PMI and Ultrasonic testing reports.

Frequently Asked Questions (FAQ)

Why should I choose a Hollow Bar over a Seamless Pipe?

While they look similar, Hollow Bars are engineered specifically for machining (Mechanical Tubing). They have thicker walls, tighter dimensional tolerances, and are manufactured to ensure better machinability and concentricity than standard fluid-conveying pipes.

How much material can I save by using Hollow Bars?

Depending on the OD and ID ratio, you can save between 30% to 50% in raw material weight compared to a solid bar. Additionally, you save significantly on energy, tool wear, and labor by eliminating the deep-hole drilling process.

Are Hollow Bars suitable for high-pressure applications?

Yes. Because they are often produced via seamless extrusion or centrifugal casting, they possess high internal strength and are regularly used for high-pressure hydraulic components.

Does Exotic Metals LLP provide honed hollow bars?

Yes, we can provide hollow bars with a honed ID (H8 or H9 tolerance) specifically for immediate use in hydraulic cylinder barrels.

Hollow Bar