Many metal components undergo burnishing and grinding to increase their durability and smoothness. Using steel balls for these processes offers certain benefits that other materials won’t provide. Learn more about these benefits, as well as the common types of burnishing media.
Metal Burnishing Overview
Burnishing is a finishing process that hardens and smoothes a metal material, increasing its overall durability and functionality. The resulting appearance is shiny and reflective, with the surface equipped to resist wear and tear, breakage, and corrosion.
The burnishing process begins when technicians place a metal part into a horizontal spinning barrel, followed by a vibratory tub containing a type of abrasive media (burnishing media ). This media vibrates against the workpiece, which becomes a smooth, polished surface free of any micro-inconsistencies.
Metal burnishing media comes in various shapes and sizes, and the choice of shape depends on the specific requirements of the burnishing process. The shape of the media can influence the effectiveness of the burnishing in terms of surface finish, deburring, and other desired outcomes. Here are some common shapes of metal burnishing media:
- Spheres: Spherical-shaped burnishing media is one of the most common types. These are small, round beads that can efficiently reach into crevices and contours of workpieces. Spherical media is effective for general-purpose burnishing and is often used in mass finishing equipment.
- Cylinders: Cylinder-shaped media has a more elongated form, which can be useful for reaching into grooves and other recessed areas on a workpiece. This shape is suitable for burnishing parts with intricate geometries.
- Cones: Conical-shaped media is tapered and can be effective for reaching into tight spaces. This shape is particularly useful for parts with pointed or conical features.
- Triangles: Triangular-shaped media is designed with sharp edges, making it effective for reaching corners and edges of workpieces. This shape is suitable for deburring and providing a more defined finish in specific areas.
- Stars: Star-shaped media has multiple points or arms extending from a central point. This shape is often chosen for its ability to reach into complex geometries and provide a thorough burnishing action.
- Ellipses/Ovals: Oval-shaped media is useful for burnishing applications where a more extended contact surface is desirable. This shape can be effective in achieving a smooth and uniform finish on flat or gently curved surfaces.
- Satellites: Satellite-shaped media consists of smaller spheres attached to a central core. This design enhances the media’s ability to reach and work on contours and recessed areas.
- Tetrahedra: Tetrahedral-shaped media has a pyramid-like structure with three triangular faces. This shape is effective for providing a concentrated and precise burnishing action in specific areas.
- Random Shapes: Some burnishing media is designed with irregular or random shapes. These may include a combination of spheres, cones, stars, and other forms. Random-shaped media can provide a more varied and thorough burnishing action.
The choice of the shape depends on the specific requirements of the workpiece and the desired outcome of the burnishing process. The selection is often influenced by factors such as the geometry of the parts, the level of surface intricacy, and the desired surface finish.
Metal burnishing media refers to small abrasive particles or pellets that are used in a process called burnishing to finish and improve the surface of metal workpieces. The media is often made of materials like steel, ceramic, or other abrasives. Here are some benefits of using metal burnishing media:
- Surface Finish Improvement: Burnishing media helps to smooth and refine the surface of metal workpieces. This results in a polished and shiny appearance, enhancing the overall aesthetic appeal of the finished product.
- Dimensional Accuracy: The burnishing process can help achieve precise dimensional control on metal parts. It can be used to remove burrs, sharp edges, and irregularities, ensuring that the final dimensions meet specifications.
- Deburring: Metal burnishing media is effective in removing burrs and sharp edges that may be present on metal workpieces after machining or other manufacturing processes. This is important for both safety and the functionality of the final product.
- Work Hardening: Burnishing can induce work hardening in the surface layer of the metal, making it more resistant to wear and improving its mechanical properties. This can enhance the durability and longevity of the finished product.
- Improved Corrosion Resistance: The burnishing process can contribute to improved corrosion resistance by closing and smoothing the surface pores of the metal. This is particularly important in applications where the metal is exposed to harsh environmental conditions.
- Enhanced Lubrication Retention: Burnishing can improve the ability of the metal surface to retain lubricants. This is beneficial in applications where reduced friction and enhanced wear resistance are important factors.
- Preparation for Coating: Burnishing can create a smooth and clean surface on the metal, making it more suitable for subsequent coating processes such as painting, plating, or powder coating. The improved surface finish can promote better adhesion of coatings.
- Aesthetic Enhancement: The polished and shiny appearance achieved through burnishing can contribute to the overall aesthetic appeal of metal products. This is particularly important in industries where visual appeal is a key factor, such as jewelry or decorative metalwork.
- Mass Finishing Efficiency: Burnishing media is often used in mass finishing equipment, making it efficient for processing a large number of metal parts simultaneously. This can lead to time and cost savings in production.
It’s important to note that the specific benefits achieved through metal burnishing may depend on factors such as the type of burnishing media used, the characteristics of the metal workpiece, and the desired outcome for the finished product.
Common Types of Burnishing Media
Depending on the project, you can use different types of ball burnishing media to burnish metal, including:
- Steel Media: Steel balls, pins, and other media are popular for many general-purpose metal burnishing applications. Steel offers superior effectiveness and durability to allow for many types of finishes, whether you need a textured or smooth finish.
- Stainless Steel Media: Some applications may also use stainless steel burnishing media to improve corrosion resistance. This media can burnish stainless steel and other materials to help protect them from contamination.
- Ceramic Media: Ceramic works best to produce a smooth surface for precision components without removing too much surface material. You can use many sizes and shapes of ceramic media to create many surface finishes.
- Plastic Media: If applications require a gentler burnishing media, polyester, polyamide, and other plastics are ideal. Specifically, plastic works for applications involving softer materials or more fragile parts, producing the desired finish without risking damage to the part.
- Porcelain Media: For fine finishing or polishing, you might use porcelain media, which produces a glossy surface on many materials.
- Dense Media: Stainless steel or steel materials like balls and pins count as dense media, which is compatible with materials requiring more aggressive metal burnishing. Using this media, you can remove surface imperfections like burrs and produce textured surfaces.
- Porcupine Media: As the name suggests, this media features protrusions that resemble porcupine quills. Applications may use this media to finish parts with complex geometries and intricate designs, allowing for improved uniformity and complete coverage.
- Dry Media: Walnut shells, corn cob media, and other types of dry media help deburr and polish parts. At the same time, this media can absorb excess moisture.
Stainless steel media holds up under exposure to extreme temperatures, making it suitable for environments ranging from cryogenics to extreme heat.
Certain stainless steel grades are magnetic, which is ideal if an application requires magnetism.
Steel Media for Burnishing and Grinding from STR Industries
Steel balls work for many applications in need of reliable burnishing media. If you want to use this material for a burnishing project, turn to STR Industries for precision steel ball manufacturing. For more information about our offerings, reach out to us today or get started on a project by requesting a quote.