BS 6323 Grade CFS 3 Seamless Tube Manufacturer & Supplier - USA Piping Solution

USA Piping Solution is a known national source for BS 6323 Grade CFS 3 Seamless Tube. This British Standard designation identifies cold-finished seamless carbon steel tubes developed for mechanical and general engineering uses. Understanding the need for dependable materials, we ensure access to certified tubing through our robust US inventory network. When your project requires the specific properties and precision offered by BS 6323 Grade CFS 3 Seamless Tube, supported by practical know-how and efficient logistics, USA Piping Solution is well-equipped to fulfill your needs.

Getting Acquainted with BS 6323 Grade CFS 3 Seamless Tube

So, what sets BS 6323 Grade CFS 3 Seamless Tube apart in the world of steel tubing? It's produced according to Part 4 of British Standard 6323, a specification focused on tubes for automotive, mechanical, and general engineering fields. The "CFS" part clearly indicates "Cold Finished Seamless," highlighting how it's made. "Grade 3" pinpoints a specific carbon steel chemistry within the standard, offering a useful balance of properties for many components.

Here’s what makes this tubing distinct:

• British Standard: It adheres to BS 6323, which may have different nuances compared to common ASTM or DIN specifications.
• Seamless Origin: Production starts with solid steel billets, meaning no weld seam exists along the tube length. This ensures consistent material properties all around.
• The Cold Finish: After initial shaping (often hot rolling), the tubes go through a cold finishing process, usually cold drawing. This critical step yields tighter dimensional tolerances (OD, ID, wall), a much smoother surface finish, and increased strength and hardness compared to hot-finished tubes, due to work hardening.
• Grade 3 Steel: This grade represents a versatile low-to-medium carbon steel, suitable for many engineering parts that require good machinability and strength. It's frequently delivered in the "as-drawn" hard condition (BK).

Engineers typically specify BS 6323 CFS 3 Tubing when they need the reliable structure of seamless tubing combined with the precise dimensions, excellent surface quality, and potentially higher strength that cold finishing delivers. It’s a solid choice for creating accurate Carbon Steel Seamless Tube components.

BS 6323 Grade CFS 3 Tubing Specifications

Complying with the specific requirements of BS 6323 Part 4 is essential for using CFS 3 tubing correctly in engineering designs. USA Piping Solution supplies materials verified against these important criteria.

Key Technical Details

Specification	Details
Governing Standard	BS 6323 Part 4 (cold finished seamless tubes) and Part 1 (general requirements)
Material Code	Grade CFS 3 (Cold Finished Seamless, Grade 3 chemistry)
Manufacturing Route	Seamless production followed by Cold Finishing (e.g., Cold Drawing)
Size Range (OD)	Up to 230 mm (approx. 9 inches); commonly used sizes in mechanical engineering
Wall Thickness	Based on ordered specs; cold finishing allows tighter control (often ±10% or better)
Common Shape	Round tubing is predominant; other shapes are possible but less common
Delivery Condition	Typically Cold Finished/Hard (BK) for strength Other options by agreement: Cold Finished/Soft (BKW): Lightly worked post-annealing Annealed (GBK): Fully softened for high formability Normalized (NBK): Heat treated after finishing for refined grain (GZF/NZF): Descaled surface finish
Lengths	Available in standard random lengths or custom cut-to-length options
Dimensional Tolerances	Tighter OD, ID, and wall control vs. hot-finished tubes; refer to BS 6323 for tolerance details

Chemical Composition and Mechanical Properties

Element	CFS 3 Limit (%)	Influence on Material
Carbon (C)	0.20 max	Primary element controlling baseline strength and hardness.
Silicon (Si)	0.35 max	Typically present as a result of steel deoxidation practices.
Manganese (Mn)	0.60 – 1.00	Key contributor to strength and hardenability.
Phosphorus (P)	0.050 max	Controlled impurity to maintain material soundness.
Sulfur (S)	0.050 max	Controlled impurity; influences machinability and toughness slightly.

This chemistry offers a good combination of mechanical properties and manufacturability.

Mechanical Property Profile (Condition Dependent)

How strong or ductile BS 6323 tubing is depends significantly on its final delivery condition after cold finishing. The standard provides minimum values for common conditions:

Property	Condition BK (Cold Finished/Hard)	Condition NBK (Normalized)	Units	Interpretation
Yield Strength (Re)	360 min	215 min	MPa	Cold working (BK) substantially raises the yield point.
Tensile Strength(Rm)	450 min	360 min	MPa	Ultimate strength is also significantly higher in the BK condition.
Elongation (A)	6% min	24% min	%	Ductility (ability to stretch) is much lower when left hard (BK).

Key Takeaways:

• BK Condition (As-Drawn/Hard): This condition leverages the work hardening from the cold drawing process, resulting in the highest strength and hardness. However, its low ductility means it's not suitable for significant bending or flaring. Choose this for strength or when machining is the main process.
• NBK Condition (Normalized): Heat treating (normalizing) after cold drawing softens the material compared to BK, greatly increasing ductility (higher elongation) and improving toughness, while generally retaining better strength than a fully annealed tube.
• GBK Condition (Annealed): For applications requiring maximum formability (severe bends, flaring), specifying the fully softened Annealed (GBK) condition is necessary (Yield ~170 MPa min, Tensile ~340 MPa min, Elongation ~26% min).
• Hardness: Follows the conditions – BK is hardest, GBK is softest, NBK falls in between. Specific hardness values can often be targeted if required.

Selecting the delivery condition (BK, NBK, GBK) that matches the application's priority—be it strength, formability, or a balance—is crucial when specifying CFS 3 tubing. USA Piping Solution can assist in sourcing material in the appropriate condition.

The Manufacturing Journey of SAE J525 Tubing

How does SAE J525 Welded Hydraulic Tubing achieve its specific blend of characteristics? It follows a well-defined production path:

1. Strip Feed: High-quality low-carbon steel, rolled flat to precise thickness and width, begins the process.
2. Roll Forming: The flat strip travels through a series of contoured rollers that gradually shape it into a round, open-seam tube.
3. Electric Resistance Welding (ERW): High-frequency electrical current heats the abutting edges of the formed strip to forging temperatures. Pressure rollers then fuse the edges together, creating a solid-state weld without filler metal. Excess weld material (flash) is typically trimmed off.
4. Post-Weld Normalizing: The continuous welded tube passes through a furnace for normalizing. This heat treatment refines the grain structure across the tube, including the weld zone, improving overall consistency.
5. Cold Drawing: After cooling from normalizing, the tube is pulled through a sizing die (and sometimes over an internal mandrel). This cold working step is vital: it improves dimensional accuracy (OD/ID/wall), creates a smoother surface, and increases the steel's strength through work hardening. J525 mandates specific minimum reductions in area during this stage.
6. Final Annealing: This is arguably the most critical step for hydraulic tubing. The cold-drawn tube is heated again in a controlled atmosphere furnace to a specific temperature (annealing). This softens the work-hardened steel, restoring the high level of ductility needed for flaring and bending, while relieving internal stresses.
7. Finishing & Verification: Final steps include straightening the annealed tubing, cutting it to desired lengths, performing thorough visual and dimensional checks, and conducting the mandatory J525 performance tests (flattening, flare, pressure/NDE).

This carefully orchestrated sequence ensures the final tubing product embodies the cleanliness, dimensional precision, pressure integrity, and crucial formability that define SAE J525.

The Cold Finished Seamless (CFS) Production Journey

Making Cold Finished Seamless Tube involves extra steps beyond basic hot forming, specifically aimed at achieving better dimensions and surfaces:

1. Starting Hollow: The process usually begins with a seamless tube already formed while hot (an HFS hollow). This serves as the raw material for the cold finishing stages.
2. Surface Preparation: To ensure a clean draw and good final surface, the hot-finished hollow might be cleaned, often through pickling, to remove any surface scale.
3. Cold Drawing: This is the core CFS step. The prepared tube is lubricated and pulled through a precision die at room temperature. The die's diameter is smaller than the tube's starting OD. Often, an internal plug or mandrel is used simultaneously to control the inside diameter and wall thickness. This drawing action:
• Reduces the tube's dimensions.
• Lengthens the tube.
• Creates tighter tolerances for OD, ID, and wall.
• Produces a much smoother, brighter surface finish.
• Increases strength and hardness due to work hardening. Achieving significant size reduction might involve multiple draws with intermediate annealing steps.
4. Finishing & Optional Heat Treatment: After the last draw, the tube is straightened, inspected, and cut. If a condition other than as-drawn (BK) is specified (like Annealed GBK or Normalized NBK), the required heat treatment is performed in a furnace at this point.
5. Final Inspection: Includes thorough dimensional checks, visual examination, and any mechanical tests required for the specified final delivery condition.

This sequence delivers the characteristic precision and enhanced surface quality associated with BS 6323 CFS 3 Tubing.

Advantages of Using CFS 3 Tubing

Choosing BS 6323 Grade CFS 3 Seamless Tube offers several benefits specifically valuable in mechanical and engineering contexts:

Key Strengths:

• Precise Dimensions: Cold drawing enables significantly tighter control over outside diameter, inside diameter, and wall thickness compared to hot-finished tubes. This precision is vital for components needing accurate fits or minimal machining allowance.
• Smooth Surface Finish: The cold finishing process yields a much smoother and brighter OD and ID surface. This reduces the need for secondary finishing and can be beneficial for applications involving seals, bearings, or aesthetic requirements.
• Enhanced Strength/Hardness (BK Condition): When supplied in the as-drawn (BK) condition, the tubing possesses increased yield strength, tensile strength, and hardness due to work hardening. This can potentially allow for designing stronger or lighter components compared to using softer materials.
• Improved Machinability: Often, the higher hardness and uniform structure of cold-drawn steel lead to better chip formation and surface finish during machining compared to softer, hot-finished counterparts.
• Seamless Reliability: The absence of a weld seam ensures consistent material properties around the tube's circumference and eliminates potential weld-related issues.

Points Worth Noting:

• Formability Limitation (BK Condition): The increased strength of the BK condition comes at the cost of ductility. Significant cold forming (like tight bending) isn't advisable in this state. Specify GBK (Annealed) or NBK (Normalized) conditions if substantial forming is required.
• Cost Factor: The additional steps of cold drawing and potential heat treatments mean CFS tubing typically has a higher initial cost than equivalent hot-finished seamless (HFS) tubes.

CFS 3 offers a blend of precision, surface quality, and mechanical properties valuable when balanced against fabrication needs and budget.

Common Uses and Industries

Thanks to its precision and good mechanical properties, BS 6323 Grade CFS 3 Seamless Tube is frequently employed in manufacturing components across various sectors:

• Automotive Manufacturing: Used for parts like suspension elements, steering components, potentially shafts, and structural pieces where tolerances and strength are important.
• Industrial Equipment: Ideal for producing precision shafts, rollers, bushings, components for hydraulic cylinders (especially if honed), bearing housings, and machine structural elements.
• General Engineering: Serves as excellent stock for creating a wide array of custom-machined items, including connectors, spacers, sleeves, fixtures, and tooling, where tight dimensions and a good finish are beneficial.
• Agricultural Machinery: Finds use in linkages, shafts, structural components, and other parts on farm equipment requiring reliable performance and precise dimensions.
• Construction Vehicles: Utilized in specific mechanical linkages, pins, bushings, and structural areas where dimensional accuracy contributes to function.

CFS 3 tubing is especially advantageous when the tube itself forms a significant part of the final component with little need for major reshaping, or when its precise dimensions reduce subsequent machining time and cost. The chosen delivery condition (BK, NBK, GBK) further tailors it for strength-dominant or formability-dominant roles.

BS 6323 CFS 3 Tubing Size Chart and Weight Chart

OD (mm)	Wall (mm)	ID (mm)	Weight ( kg/m )	Weight (lbs/ft)	Notes
25.0	2.0	21.0	1.15	0.77
25.0	3.0	19.0	1.65	1.11
30.0	2.5	25.0	1.74	1.17
30.0	4.0	22.0	2.64	1.78
38.0	3.0	32.0	2.64	1.78
38.0	5.0	28.0	4.12	2.77
45.0	4.0	37.0	4.07	2.74
45.0	6.0	33.0	5.79	3.90
50.0	3.0	44.0	3.57	2.40
50.0	5.0	40.0	5.71	3.84
60.0	4.0	52.0	5.61	3.77	Common Size
60.0	6.0	48.0	8.06	5.42
75.0	5.0	65.0	8.79	5.91
75.0	8.0	59.0	13.5	9.08	Heavy Wall
90.0	6.0	78.0	12.5	8.41
90.0	10.0	70.0	19.9	13.4
110.0	8.0	94.0	20.2	13.6
110.0	12.0	86.0	29.3	19.7

Disclaimer: Illustrative data. Actual weights depend on specific dimensions within tolerance ranges. Use detailed calculations for critical weight assessments.

Quality Confirmation: Certification and Compliance

Verifying that BS 6323 Grade CFS 3 Seamless Tube meets the requirements of the standard is accomplished through standard documentation and quality checks.

• BS 6323 Standard Compliance: Materials supplied are certified by the manufacturer to meet the stipulations of BS 6323 Parts 1 and 4 for Grade CFS 3. This covers the defined chemistry, seamless cold-finished production, dimensional accuracy, and the mechanical properties associated with the ordered delivery condition (BK, NBK, GBK, etc.).
• Mill Certification Provided: Shipments are typically accompanied by Mill Test Certificates (MTCs) or Certificates of Conformance (CoC), often following formats like EN 10204 3.1. These documents provide traceability (via heat number) and confirm the chemical analysis. Results of mechanical tests are included when performed based on the specified delivery condition.
• ISO 9001 Quality Practices: Our internal procedures adhere to ISO 9001 certified quality management principles, ensuring consistency in how we manage suppliers and verify materials.
• Product Markings: Tubing is usually marked (stenciled or tagged based on size) according to standard practices, typically including:
• Manufacturer's mark
• BS 6323 Pt 4 standard reference
• CFS 3 Grade designation
• Dimensions (OD x Wall)
• Delivery condition code (e.g., BK)
• Heat number or other trace code.

This documentation provides essential confirmation of conformity for engineering records and manufacturing quality control.

Why Choose USA Piping Solution for BS 6323 CFS 3 Tubing?

Working with a supplier familiar with specific international standards like BS 6323 can streamline procurement. USA Piping Solution offers solid reasons to consider us for your BS 6323 Grade CFS 3 Seamless Tube needs:

• Standard Knowledge: Our team understands the specifics of BS 6323, including Grade CFS 3 characteristics and the significance of different delivery conditions, enabling us to better assist you.
• Efficient Sourcing: While BS standards may be less common domestically than ASTM, we leverage established relationships to source high-quality BS 6323 CFS 3 tubing effectively.
• Inventory & Access: We carry a wide range of seamless mechanical tubes and can efficiently access specific BS 6323 requirements through our supplier network.
• Reliable Logistics: Our distribution system ensures dependable and timely delivery of materials across the United States.
• Quality Focus: We prioritize sourcing from reputable mills known for adhering to British Standards and ensure appropriate certification accompanies the materials.
• Processing Support: We offer value-added services like precision cutting to length, helping prepare the tubing for your specific manufacturing steps.
• Clear Communication: Our sales and support staff aim for prompt responses, accurate information, and smooth handling of all inquiries and orders.

Exploring Related Pipe and Tube Products

Beyond BS 6323 CFS 3, USA Piping Solution provides a broad selection of seamless tubing and pipe manufactured to various widely used standards:

Identifying the precise requirements of your application—mechanical vs. pressure, dimensional needs, surface finish, governing standard—is crucial for selecting the right tubular product. Our team is available to help clarify these distinctions.

Fulfill Your Requirements for BS 6323 Grade CFS 3 Seamless Tube

For engineering projects needing the dimensional precision, smooth finish, and reliable performance of cold-finished seamless tubing manufactured to British Standards, consider BS 6323 Grade CFS 3 Seamless Tube sourced through USA Piping Solution. We provide access to certified material, backed by responsive service and efficient US-wide delivery. Let us assist with your specific Carbon Steel Seamless Tube needs under BS 6323.

Contact USA Piping Solution to discuss your BS 6323 Grade CFS 3 Seamless Tube specifications. We will provide a tailored and competitive quotation promptly.

Request Your BS 6323 CFS 3 Tubing Quote Now!