Category Archive: Products

Materials Spotlight: 917 Tin Bronze

Accurate Specialties has been an industry leader in the manufacture of bronze gear blanks in North America since our establishment in 1987. We are pleased to operate as a full-service bronze foundry, and offer support from the beginning of the design process through completion of precisely machined, ready-to-use bronze gear blanks.

917 Tin Bronze Properties

917 Tin Bronze is a copper-tin alloy with a particularly high tin content that is frequently used in applications with low speeds and heavy loads. 917’s particular strength, corrosion-resistance, high ductility, and low-wear capabilities make it an excellent option for a number of parts and components, including:

  • Worm and comprise gears
  • High strength bushings
  • Bearings for heavy loads and low-speed applications
  • Steam fittings
  • Piston rings
  • Valve bodies
  • Pump impellers

Superior 917 Tin Bronze Gear Blanks from Accurate Specialties

Centrifugally cast bronze gear blankAt Accurate Specialties, we are pleased to provide high-quality, fully machined bronze gear blanks, including gear blanks made from 917 Tin Bronze. With over 30 years of dedicated bronze casting experience, we are North America’s leading bronze gear blank manufacturer. Accurate Specialties is proud to be ISO 9001:2015 certified, so we can guarantee the best in bronze casting products and services. Our specialties include chill casting, centrifugal casting, spuncast gear blanks, and continuous casting.

Attributes of Bronze Alloys

Bronze is an alloyed metal typically composed of copper blended with tin. It can also be produced by alloying copper with other metals, such as aluminum and manganese, depending on its intended use.

Bronze has been employed by humans in a wide range of applications for thousands of years. Bronze was eventually replaced by iron alloys due to the ready availability of iron, but its overall useful characteristics make bronze a commonly used alloy to this day. Bronze is used to make all manner of everyday objects, such as:

  • Sculptures and musical instruments
  • Decorative medals
  • Electrical products
  • Bellows in appliances and HVAC equipment
  • Springs and washers
  • Industrial components
  • Nautical equipment

As with all alloys, bronze comes in a number of different alloys and grades. The percentage of copper to other metals in the alloy can be adjusted to meet the needs of a given applications.

Tin bronze, in particular, is valued for its high tensile strength, low lead content, fine-grained texture, friction resistance, and high resistance to fatigue. Its high corrosion resistance makes it useful in marine and chemical applications where iron-based alloys might rust or corrode. In addition, tin bronze’s high ductility ensures that it retains shape even under high stress and repeated pressure.

The Accurate Specialties Advantage

Our state-of-the-art equipment and highly trained specialists ensure that our customers receive the best possible service from engineering design through the completion of the manufacturing process. We offer a high degree of flexibility and our integrated and responsive manufacturing techniques ensure that products are completed to even the most exacting specifications.

With our top-of-the-line vertical turning center, we are capable of producing large-scale bronze gear blanks with exceptional speed and accuracy, thereby reducing the overall cost of production. In addition to our primary manufacturing services, we are pleased to provide finishing services, including drilling and hole tapping, so that our customers receive finished and ready-to-use products.

For more information on our exceptional bronze casting products and services, please contact us or request a quote today.

Advantages of Centrifugal Casting

When it comes to manufacturing gear blanks, centrifugal casting holds several advantages over other methods.

The process involves pouring molten metal into a rapidly spinning mold cavity. The force produced by the mold’s spinning forces the material to conform to the shape of the mold. Additionally, extreme pressures that form within the casting device drive material contaminants to the center of the casting, allowing them to be easily removed in future finishing operations.

Advantages of the Centrifugal Casting Process

There are a number of advantages to using centrifugal casting for the manufacture of cylindrical and circular parts, such as:

  • Greater strength. The greater strength of parts produced using centrifugal casting is a result of higher density grain structures. As the process allows for more control over directional solidification, the grain structure is more uniform and its mechanical properties are almost equal in all directions. This higher structural density increases the life span of the component and allows for higher stress tolerances. Another factor that contributes to the enhanced part strength is higher product purity, which eliminates internal porosity and improves structural uniformity.
  • Increased product purity. During the casting process, the spinning of the mold places extreme pressures on the molten material. This pressure causes lighter contaminants and impurities to separate from the denser metal. These impurities gather in the bore of the component, minimizing the risk of formation of weak points or areas of porosity within the metal structure. The machining process following casting removes these impurities, leaving a highly pure end-product.
  • Better production cost-efficiency. Increased product purity also affects production cost-efficiency. As impurities gather at the interior surface of the part and are machined out, there is a reduction in the number of defective parts and rejects. The lack of porosity produced through the centrifugal casting process also allows manufacturers to use less metal and produce less material waste. In addition, faster setup and shorter production cycle times lead to improved production cost-efficiency.

Limitations of Centrifugal Casting

Although centrifugal casting offers several manufacturing advantages, the process is limited in its production capabilities. Some of the limitations of centrifugal casting include:

  • Size. To avoid the creation of a parabola at the bottom of the casting—which increases machining time—the height-to-diameter ratio used in vertical casting is 2:1. This requirement limits the size of the produced part. In some cases, horizontal casting provides the solution to these limitations​.
  • Internal diameters. Designs with smaller internal diameters also pose a challenge for centrifugal casting operations. The purity and strength advantages of centrifugal casting decrease as the inside diameters of the components decreases. The issue stems from the higher RPMs required to produce the necessary G forces to form the cast product. Although these speeds are possible, there are significant safety issues related to operating at higher RPMs.
  • Shape. The centrifugal casting process only provides production advantages to parts with a cylindrical geometric shape. Although other mold shapes are possible, the loss of the structural and purity benefits and the additional cost of the unique die and post-processing operations make its use impractical outside of producing cylindrical shapes.

Additional Casting Services From Accurate Specialties

At Accurate Specialties, we offer a broad range of casting capabilities. In addition to centrifugal casting, we provide:

  • Spin casting. This type of casting allows for the production of parts with high material purity and consistent weight and density. Additionally, when used for the manufacture of bronze gear blanks, the process creates stronger bonds between the gear tooth and hub.
  • Chilled casting. This casting method produces cast products with tight grain structures and outstanding uniformity. These properties result from pouring molten bronze into an aluminum or steel mold, which is at a significantly lower temperature, producing a rapid cooling or “freezing” effect.
  • Continuous casting. Continuous is cost-effective for large volumes of simple parts. It produces parts with favorable mechanical properties, even distribution of alloy agents, and better machinability, friction, and wear properties. The process involves pouring molten bronze alloys through a graphite mold, cooling them into 12-foot bars, and cutting them into “pucks” for further formation.

Bronze Centrifugal Casting Solutions From Accurate Specialties

For the manufacture of cylindrical and circular parts, centrifugal casting offers several advantages, including greater part strength, higher product purity, and better cost-effectiveness.

At Accurate Specialties, we utilize several casting methods—including centrifugal casting—to produce high-quality bronze gear blanks for our customers. Our solid bronze gear blanks are available in diameters ranging from 1–50 inches.

To learn more about our centrifugal casting solutions, contact us or request a quote today.

Materials Spotlight: Aluminum Bronze 954 & 955

Accurate Specialties, Inc. is an ISO 9001: 2015 registered full-service bronze foundry that manufactures bronze gear blanks. Our full-service process includes many steps such as design assistance, alloy selection, casting, and machining. We create customized bronze gear blanks for corporations and facilities across North America, specializing in the following industries:

  • Centrifugal Casting
  • Chill Casting
  • Continuous Casting
  • Spuncast Composite (iron under Bronze) Gear Blanks

Depending on the specifications of the industry and the application, customers can specify specific bronze alloys or our design specialists can suggest an alloy for different designs. Some of the most common standard bronze alloys we use to craft and machine gear blanks include manganese bronze alloys, tin bronze alloys, and aluminum bronze alloys—e.g., aluminum bronze C-955 and aluminum bronze C-954.

Aluminum Bronze C-954 Available for Manufacturing

Aluminum bronze C-954 is a sturdy, versatile alloy that can be used to cast a wide range of designs and components across different industries. The material is well-known for being abrasion-resistant, which is essential when the part comes into contact with other components.

Parts made of C-954 experience less wear and friction, as well as demonstrate a lowered risk of seizing in systems that use this material in contact with dissimilar metals. This alloy also resists cavitation and deformation under high loads and is extremely resistant to tarnishing and corrosion, including corrosion due to atmospheric conditions and exposure to seawater. These characteristics make it an ideal alloy for use in the aerospace, marine, oil and gas, and transportation industries.

Aluminum bronze 954 is also popular for manufacturing applications because it is highly weldable and machinable without losing tensile or yield strength. It is a top choice for many parts, designs, and applications that need to be both durable and affordable. Some of the most common commercial and industrial component manufacturing applications for 954 include:

  • Bearings
  • Bushings
  • Gears, such as high strength, low operating speed, worm-type, and spur-type gears
  • Pickling hooks and baskets
  • Valve components

What to Know About Aluminum Bronze C-955

Aluminum bronze C-955 is another popular bronze alloy that is strong, resistant to corrosion, and can be used to cast custom designs. Although similar to C-954 in most other respects, this alloy contains nickel, which strengthens and hardens the material. Some of the other benefits of C-955 also includes:

  • Ease of use in soldering and arc welding fabrication processes
  • High levels of tensile and yield strength
  • Resistance to heat
  • Long-lasting toughness without degradation due to environmental conditions

These characteristics make it an ideal alloy for industrial environments that require parts capable of handling high loads and high levels of shock or impact without cracking or weakening. Finding application in a wide range of industries, this material is commonly used for the following components:

  • Agitators
  • Bushings
  • Gears
  • Gun coil mechanisms
  • Landing gear parts
  • Pickling hooks and baskets
  • Seats in aircraft engines
  • Valve guides

Contact Accurate Specialties

Aluminum bronze C-954 and C-955 share many of the same characteristics and potential applications. However, determining the optimal bronze alloy to use for a component can depend on the nature of the custom design and the work environments the components are designed for.

Accurate Specialties prides itself on casting and machining bronze gear blanks that precisely match our clients’ designs and needs every time. We offer fast production lead times for high-quality parts, cutting edge production systems, and responsive customer service. To learn more about aluminum bronze 954 and 955, contact us today or submit the details of your project and request a quote.

The Bronze Worm Gear Manufacturing Process Begins with Great Gear Blanks!

Since the late 1980s, Accurate Specialties, Inc. has become North America’s leading manufacturer of bronze gear blanking. We are an ISO 9001:2015-certified manufacturer and our cutting-edge horizontal and vertical turning centers allows us to produce bronze gear blanks with high precision and quality.

Accurate Specialties is a full-service bronze foundry that offers clients the following competitive advantages:

  • Integrated Manufacturing
  • Reduced Total Costs
  • Quick Response Times
  • Component Reduction
  • Manufacturing Flexibility
  • Engineering Design Assistance
  • Complete Material Integrity
  • Responsive Manufacturing
  • Short Lead Times

How Are Gears Manufactured?

The most effective method for gear manufacturing depends upon a number of factors, such as manufacturer capabilities and the desired end application. There are three basic types of gear manufacturing: broaching, hobbing, and gear machining.

  • Manufacturers typically employ gear broaching to produce steel shafts and splines or define unusual gear shapes. Manufacturers pull the broach cutting tool through an object. As the tool is pulled through, the size of the leading edge—or tooth—gradually increases until the intended design shape is formed.
  • Gear hobbing produces small helical gears, spur gears, sprockets, and splines. Gear hobbing is a generating process, which means that the final tooth shape is not directly related to the shape or form of the cutting tool. The cutting tool (hob) and the workpiece are in a continual state of rotation during operations, gradually forming the gear teeth as the hob traverses the workpiece surface.
  • CNC gear machining is a high-precision method of forming a wide range of gears, such as internal gears, worm gears, sprockets, spur gears, and helical gears. Gear machining typically involves milling or other cutting operations.

Gear Blanks for Gear Manufacturing

Gear blanking refers to the initial metal cutting operations that form a rough material into the contour of a gear part. At Accurate Specialties, we use a number of different processes for our gear blank manufacturing. These processes include:

  1. Chill casting: Molten bronze is poured into a die base fabricated from aluminum or steel. The lower temperature of the die causes the bronze to cool rapidly from the outside to the center. The end result is a bronze gear blank with exceptional uniformity and a particularly fine grain structure.
  2. Centrifugal casting: Centrifugal casting produces gear blanks with very high purity levels and a fine, dense grain structure. We spin the casting die at high speeds, resulting in generated pressure up to 60 times the force of gravity. As a result, all imperfections and impurities are channeled into a centralized riser area. After it is cooled, the centralized riser material is machined out, resulting in a gear part free of shrinkage cavities, gas pockets, and blowholes. 
  3. Spin casting: In spin casting, a bronze rim encompasses a hub of steel or cast iron. Lugs in this hub are filled with molten bronze, creating the section of the blank that will form into gear teeth. Since the shrinkage rate of bronze is greater than that of cast iron and steel, the bronze mechanically bonds to the hub, creating a very strong bond.
  4. Continuous casting: This process allows for part-specific casting. Batches of molten bronze alloy flowing through a graphite mold produce continuous cast alloys, which subsequently cool in tubes or bars.

Accurate Specialties offers a full range of casting processes to ensure the production of high-quality gear blanks for a variety of applications.

If you’re interested in learning more about the gear blanking services we offer at Accurate Specialties, Inc., reach out to us or request a quote.

Applications for Spuncast Composite Gear Blanks

Accurate Specialties is the leading manufacturer of spuncast composite gear blanks. Our spuncast gears deliver the durability and strength of bronze gears while cutting material costs via the use of steel or cast-iron center hubs. Our process and material choices offer the high level of quality and performance you expect at a much lower price point. Our spuncast composite gears are well-suited for use in most any relevant application.

Choosing Accurate Specialties for Spuncast Composite Gear Blanks

As a top manufacturer of spuncast composite gear blanks, we have learned how to make our solutions cost-effective. Our cast iron or steel center hubs we utilize are more affordable than crafting a full bronze gear blank, and without the need for spacers, our composite gears cut the need for added assembly processes. In addition, we receive a bulk discount on materials due to the high volumes of spuncast composite gear blanks that we fabricate, and these savings are passed on to our clients.

We also offer quick turnaround times for your composite gear orders. Components can be completed in as little as one week. Accurate Specialties utilizes integrated manufacturing processes to offer the manufacturing flexibility our customers demand. We guarantee the integrity of all materials, and our strict quality management process ensures a high quality end product.

Industries & Applications

Accurate Specialties’ spuncast composite gear blanks are well-suited for use in most any industry where gear blanks are used. They are relied upon in critical applications across industries such as:

Power Transmission

We offer spuncast composite gear blanks in a range of sizes to meet the demands of most power transmission applications. We also produce bronze gear blanks that are centrifugal cast or chill cast, with a range of common and specialty alloys available.

Our gear blanks are used in the following power transmission applications:

  • Conveyor systems
  • Mining equipment
  • Elevators
  • Escalators
  • Center point irrigation systems
  • Hoists
  • Cranes
  • Milling and manufacturing equipment
  • Screw conveyors and augers
  • CAT scanner positioning systems
  • Solar panel positioning systems

Machine Tools

Our spuncast composite gear blanks can handle demanding loads placed upon them by precision machine tools while delivering sheer resistance in environments where backlash is minimal. Our gear blanks are designed for dependable operation, and made from heavy-duty materials.

You will find our gear blanks in the following machine tool applications:

  • Machine tool components
  • Rotary tables for machine tools
  • Indexing tables for machine tools


Our gear blanks are utilized in various marine applications, and may be customized to meet your specific design requirements.

Marine applications that have utilized our gear blanks include:

  • Boat lifts
  • Cable & wench systems
  • Bilge pumps
  • Water pumps


Our spuncast composite gear blanks deliver superior reliability for the automotive industry. Components may be manufactured to meet exact specifications and are made in a variety of sizes to suit the varying needs of the automotive sector.

You can find our gear blanks in the following automotive applications:

  • Steering mechanisms
  • Gear boxes
  • Gear-drive power transmissions

Gear Blanks for All Industries

Accurate Specialties is an industry leader in the manufacture of reliable spuncast composite gear blanks across the above applications and many more. Request a quote today to learn how our gear blanks deliver superior performance and savings in your application.



Applications for Bronze Alloys

At Accurate Specialties, Inc. (ASI) we work to satisfy our customer requests and design specifications using optimal alloys to cast a wide range of bronze gears and composite gears for a comprehensive array of applications. We work with numerous bronze alloys, each delivering desired advantages for particular operations. Our expertise guides clients in selecting the best bronze alloy for their needs.


The Copper Development Association

The Copper Development Association (CDA) works to expand the copper market worldwide through its commitment to educating producers, fabricators, and end users regarding the benefits and uses for copper and copper alloys. With a commitment to helping copper businesses thrive, the CDA supports each application where copper plays a role.


Bronze Alloys and Their Applications

Accurate Specialties, Inc. offers a wide selection of bronze alloys to serve the varying needs of our clients. Various alloys can be created specifically to meet the needs of even the most unique or demanding applications. By consulting with each client, we will determine the best choice for your intended purpose or design. Some of the most common alloys we use include:


863 Manganese Bronze

Known for its high-strength and corrosion-resistance, this bronze alloy also features durability and longevity, making it an ideal option for heavy-duty applications such as construction and agricultural equipment. 863 Manganese Bronze is popular in bronze alloy applications such as:

  • Screw-down nuts
  • Load bearings
  • Bronze for gears
  • Cams
  • Gibs
  • Large stem valves
  • Bridge pins
  • Hydraulic cylinder components


907 Tin Bronze

This alloy offers quality corrosion resistance, especially in applications with seawater exposure. This bronze alloy is moderately machinable and performs well in wear and fatigue applications. 907 Tin Bronze is utilized in bronze alloy applications such as:

  • Bearings
  • Bushings
  • Bronze for gears
  • Piston rings
  • Pump components
  • Marine fittings


917 Tin Bronze

Typically selected for its increased load carrying capacity – especially heavy loads involving slow and irregular movement – this alloy is highly corrosion resistant and requires adequate lubrication.

917 Tin Bronze is commonly used for applications such as:

  • Bearings with slow speed and high load
  • Gears
  • Movable bridge components
  • Wheels in worm drives
  • Turntables for bridges


954 Aluminum Bronze

This extremely strong bronze alloy  features superior corrosion resistance. It is the most popular aluminum bronze alloy, selected for its exceptional elevated temperature strength, weldability, high tensile and yield strength, as well as ductility. 954 Aluminum Bronze is commonly used in bronze alloy applications such as:

  • Worms and worm gears (low speed/high strength)
  • Spur gears
  • Bushings
  • Bearings
  • Pickling (baskets/hooks)
  • Valve components


955 Aluminum Bronze

This alloy is among the toughest non-ferrous alloys available. It offers superior yield and compressive strength with high hardness and elongation. 955 Aluminum Bronze offers good corrosion resistance to seawater, as well as impressive heat resistance. It is weldable with good machinability. 955 Aluminum Bronze is found in applications including:

  • Bushings
  • Agitators
  • Landing gear components
  • Bronze for gears
  • Pickling (baskets/hooks)
  • Worms
  • Aircraft engine (seats, valve guides)

Bronze Alloys: Request a Quote

ASI is a leading North American manufacturer of blank gears. With our own bronze foundry and machine shop, we provide end-to-end fabrication services for a wide range of customer needs. We offer quick turnarounds, often delivering in only a week. Customers should note that ASI does not currently cast bronze alloys with high lead content (for example, 928, 932, and 943).


To learn more about ASI and our products and services, please request a quote or contact us.