Bronze Round Bar 655 Unpolished H04 Temper 0.375″ x 36″ – OnlineMetals

Description

Product Overview

OnlineMetals’ 655 Bronze Round Bar is a premium silicon bronze alloy engineered to meet the stringent requirements of ASTM‑B98. The material combines copper, tin, and a small amount of phosphorus to create a bronze that is both strong and highly resistant to corrosion, especially in saltwater and other aggressive environments. Its H04 temper indicates that the bar has been work‑hardened to a medium strength level, providing a balanced mix of ductility and tensile strength that makes it suitable for a wide range of mechanical applications. The unpolished mill finish preserves the natural surface texture of the alloy, allowing for easy post‑processing such as machining, welding, or surface treatment without the need for additional preparation. With a precise diameter of 0.375 inches and a length of 36 inches, this round bar offers consistent dimensions that simplify design calculations and reduce material waste during fabrication.
The bar is supplied in a compact package measuring 36 × 0.6 × 0.5 inches and weighing approximately 1.23 pounds, making it easy to store, handle, and ship to job sites or workshops. Each piece is stamped with the model number 67912, ensuring traceability throughout the supply chain and providing confidence that the exact specification has been delivered. OnlineMetals adheres to rigorous quality‑control protocols, including dimensional inspection, hardness testing, and visual examination for surface defects, guaranteeing that every bar conforms to the ASTM‑B98 standard and the declared H04 temper. This level of consistency is essential for engineers and fabricators who rely on precise material properties to achieve tight tolerances in critical components such as marine fittings, gear shafts, and custom‑machined parts.
Because the alloy is classified as silicon bronze, it exhibits a unique combination of strength and formability that allows it to be bent, forged, or rolled without cracking, while still maintaining its protective properties. The H04 temper further enhances its mechanical performance by increasing yield strength, making the bar suitable for load‑bearing applications where both durability and flexibility are required. In addition, the unpolished mill finish provides a matte surface that reduces glare and is less prone to showing scratches during handling, which can be advantageous in environments where visual inspection is critical. The bar’s compatibility with common joining methods such as brazing, soldering, and mechanical fastening expands its versatility across a broad spectrum of engineering projects.
OnlineMetals maintains a robust inventory management system that tracks each batch of bronze round bar from raw material acquisition through final shipment, ensuring that customers receive products that are both fresh and consistent. The company’s commitment to sustainability includes sourcing copper and tin from suppliers that follow environmentally responsible mining practices, and the manufacturing process is optimized to minimize waste and energy consumption. For customers who require documentation, OnlineMetals can provide material test reports, mill certificates, and compliance statements upon request, facilitating easy integration of the product into regulated industries such as aerospace, marine, and medical device manufacturing. The combination of traceability, environmental stewardship, and rigorous testing makes this bronze round bar a reliable choice for demanding applications.
Beyond its mechanical advantages, the 655 bronze round bar aligns with sustainability goals by offering a material that can be recycled at the end of its service life without loss of alloy properties. Reclaimed copper and tin from the alloy can be re‑refined and used to produce new bronze components, reducing the demand for virgin metal extraction and minimizing environmental impact. OnlineMetals also supports custom cutting services, allowing customers to request specific lengths or diameters beyond the standard 0.375 inch by 36 inch configuration, thereby optimizing material utilization and reducing waste. The company’s engineering team can collaborate with clients to select appropriate heat‑treatment processes or surface finishes tailored to unique project requirements, ensuring that the final product meets exact performance criteria while adhering to responsible manufacturing practices.

Usage

In marine environments, the combination of copper, tin, and phosphorus in 655 bronze provides superior resistance to seawater corrosion, making the round bar an ideal choice for components such as propeller shafts, marine fasteners, and underwater fittings. The H04 temper ensures that the material can absorb dynamic loads without cracking, while the unpolished finish reduces the likelihood of galvanic corrosion when interfaced with other metals. Engineers designing vessels, offshore platforms, or coastal infrastructure can rely on this bronze round bar to maintain structural integrity over long service lives, even when exposed to salt spray and tidal fluctuations.
The bar’s excellent machinability also makes it suitable for manufacturing fasteners, bushings, and shafts that require tight tolerances and smooth surface finishes. When turned on a lathe, the material produces a clean chip and retains its dimensional accuracy, allowing for the production of precision‑engineered parts such as bearing sleeves, gear shafts, and custom‑fit connectors. Its ability to be easily brazed or soldered further expands its applicability in assemblies where a strong, corrosion‑resistant joint is essential, such as in marine pump housings or offshore valve assemblies.
For industrial applications beyond marine use, the 655 bronze round bar serves as a reliable component in automotive, aerospace, and heavy‑equipment contexts where both strength and corrosion resistance are required. Its fatigue‑resistant properties enable the fabrication of rotating shafts, couplings, and load‑bearing brackets that endure repetitive stress cycles without premature failure. Additionally, the material’s compatibility with standard cleaning and surface‑treatment processes allows manufacturers to achieve desired aesthetic finishes or protective coatings, further tailoring the product to specific performance criteria.
In addition to standard marine and industrial uses, the 655 bronze round bar is frequently employed in artistic and decorative projects where its warm copper hue and smooth finish add visual appeal. Sculptors and metal artists appreciate the alloy’s ability to be hand‑shaped, welded, and patinated, creating intricate pieces that retain structural strength. The bar’s compatibility with traditional patina chemicals, such as liver of sulfur or copper nitrate solutions, enables creators to achieve a range of surface colors from deep browns to verdigris greens. This versatility makes the material a popular choice for custom jewelry, ornamental hardware, and architectural accents that demand both aesthetic quality and durability.

Why Choose Us

OnlineMetals has built a reputation over two decades as a trusted supplier of high‑quality metal alloys to engineers, fabricators, and hobbyists worldwide. The company’s extensive network of mills and foundries enables it to source premium silicon bronze that meets or exceeds ASTM‑B98 specifications, ensuring that every round bar delivered to customers possesses the exact chemical composition and mechanical properties required for demanding applications. By maintaining direct relationships with manufacturers, OnlineMetals can offer competitive pricing without compromising on material integrity, providing a cost‑effective solution for projects ranging from small‑scale prototypes to large‑volume production runs.
The quality assurance program at OnlineMetals includes multiple checkpoints, such as chemical analysis, dimensional verification, and hardness testing, all performed by certified technicians using calibrated equipment. Each batch of 655 bronze round bar is accompanied by a mill test report that documents compliance with ASTM‑B98, H04 temper specifications, and the exact dimensions of the product. This level of transparency gives engineers confidence that the material will perform as expected in critical applications, reducing the risk of unexpected failures and simplifying the engineering validation process. Moreover, the company’s inventory management system ensures rapid order fulfillment, often shipping within 24 hours of purchase.
Customer support is a cornerstone of OnlineMetals’ service model. The technical support team is available to answer material‑selection questions, provide guidance on machining parameters, and assist with compliance documentation for regulated industries. In addition, the company offers a hassle‑free return policy and a dedicated after‑sales liaison to address any issues that may arise after delivery. This comprehensive support framework ensures that buyers not only receive a high‑quality bronze round bar but also benefit from expert advice throughout the product lifecycle, enhancing overall project success and satisfaction.
OnlineMetals also prioritizes environmental responsibility by implementing recycling programs for scrap metal generated during production and by optimizing energy usage across its facilities. The company’s commitment to reducing carbon footprint includes sourcing copper and tin from suppliers that adhere to responsible mining standards and utilizing renewable energy sources where feasible. Clients benefit from this eco‑friendly approach through reduced material costs and the assurance that their projects align with green manufacturing practices. By choosing a supplier that integrates sustainability into its core operations, customers can meet both performance specifications and corporate social responsibility goals without compromise.

Key Features

• Consistent 0.375‑inch diameter and 36‑inch length provide precise stock dimensions, reducing setup time, minimizing material waste, and simplifying CNC programming for efficient machining operations.
• The H04 temper delivers medium strength combined with good ductility, allowing the bar to absorb dynamic loads, resist deformation, and maintain shape integrity in demanding mechanical applications.
• An unpolished mill finish offers a matte surface that minimizes glare, resists scratches, and reduces the need for additional surface preparation, facilitating visual inspections and preserving aesthetic quality during handling.
• Excellent corrosion resistance to seawater, salt spray, and a wide range of industrial chemicals makes the bar ideal for marine hardware, fasteners, bushings, and shafts that are continuously exposed to harsh environments.
• OnlineMetals provides detailed mill test reports, fast 24‑hour shipping, and dedicated technical support, ensuring reliable delivery, easy compliance verification, and ongoing assistance throughout the product’s lifecycle.

FAQ

What are the mechanical properties of the 655 bronze round bar?

The 655 bronze, also known as silicon bronze, typically contains about 96% copper, 3% tin, and a small percentage of phosphorus, which together give the alloy its characteristic strength and corrosion resistance. In the H04 temper, the material exhibits a tensile strength of approximately 70 ksi (480 MPa) and a yield strength around 55 ksi (380 MPa), while maintaining an elongation of 20% in standard testing. These properties provide a good balance between hardness and ductility, allowing the bar to be machined, formed, or welded without cracking. Additionally, the alloy’s fatigue limit is suitable for rotating shafts and components subjected to cyclic loading, making it a reliable choice for marine hardware, fasteners, and other demanding applications.

Can the 655 bronze round bar be welded or brazed?

The 655 bronze round bar can be readily joined using both welding and brazing techniques, thanks to its silicon bronze composition which offers good wetting characteristics. For welding, gas tungsten arc welding (GTAW) with appropriate filler rods such as ER655 or ERCuSi‑A provides strong, corrosion‑resistant joints. Brazing is often preferred for marine applications; using a copper‑phosphorus or silver‑based brazing alloy at temperatures between 1,150 °F and 1,300 °F yields a durable bond without compromising the base material’s properties. Proper surface preparation, including cleaning and flux application, is essential to achieve optimal joint strength. Both methods maintain the alloy’s inherent corrosion resistance, ensuring that the assembled component performs reliably in harsh environments.

What certifications and test reports are provided with the product?

Each 655 bronze round bar shipped by OnlineMetals is accompanied by a comprehensive mill test report that verifies compliance with ASTM‑B98 specifications and confirms the H04 temper condition. The report includes chemical composition analysis, dimensional measurements, hardness values, and tensile test results, providing full traceability from raw material to finished product. Customers in regulated industries such as aerospace, marine, and medical device manufacturing can request additional certifications, such as ISO 9001 or RoHS compliance documentation, to meet specific project requirements. These detailed reports facilitate quality assurance, simplify material verification processes, and give engineers confidence that the material will perform as expected in critical applications.

How should the round bar be stored and handled to maintain its quality?

To preserve the integrity of the 655 bronze round bar, it should be stored in a dry, well‑ventilated area away from direct exposure to moisture, chemicals, or extreme temperature fluctuations. Keeping the material in its original packaging or in sealed containers helps prevent surface oxidation and maintains the unpolished finish. When handling, use gloves or protective equipment to avoid fingerprints and scratches, and support the bar along its length to reduce bending stresses. For long‑term storage, consider applying a light coat of corrosion‑inhibiting oil or a protective wax, especially if the bar will be kept in a humid environment. Proper storage practices ensure that the alloy retains its mechanical properties and corrosion resistance throughout its service life.