Processes and Capabilities

 
Rotaloc utilizes more than 25 different manufacturing processes for the production of components. Our in-depth experience with a wide range of processes allows us to incorporate design considerations that other companies cannot, providing the most suitable part for a given application. Many of the components we produce are multi-material parts that undergo multiple manufacturing processes. Click the hyperlinks below to jump to that section (index moved to the end for the time being).
Casting
Investment Casting/Lost-Wax Casting
Investment casting, often also referred to as lost-wax casting, is a multi-step casting process that uses wax replicas to produce finished metal parts.  The part or multi-part pattern is created in wax (often by injection molding) and then dipped into a ceramic and stucco bath to form a hard shell around the wax. The wax and ceramic is then placed into an oven so that the wax melts out of the part, leaving only the outer shell with a mold cavity. Molten metal is poured into the shell cavity to form the part or parts, and once cool, are broken out of the shell. Often a cutting or finishing process is required to complete the parts. This process is ideal for creating very intricate, precise parts with smooth surfaces that require only a fraction of secondary machining. Investment casting allows manufacturers to create parts that would be difficult or impossible with other casting methods, as well as removing parting lines.  
Sand Casting
Sand casting consist of creating single-use mold cavities from sand. Molten metal is poured into the sand mold and forms a metal part. The sand used typically has some sort of binding agent that helps to create a strong mold that is less likely to crumble until the final de-molding process. The top half of the mold, called the cope, usually has a runner hole to pour metal into and a riser hole to allow air to escape from inside the mold. The bottom half, called the drag, is combined with the cope once they are both ready for casting. Sand casting is a one of the most flexible and forgiving metal forming processes as the process can produce parts of greatly varying size, complexity and quantity while still being produced economically. Tooling for sand casting is typically less expensive than other methods and has shorter lead times. 
Die Casting
Die Casting is the process of forming metal components from molten metal fed into a mold cavity, where the metal cools and takes the shape of the mold. This process is ideal for making large quantities of metal parts with high-quality surface finishes. Die casting also requires minimal 'clean up' to finish the part. Rotaloc is able to make our own Die Casting molds in-house, so no third party die maker or machine shop is required, reducing cost and lead time. Some Rotaloc inserts that are created via die casting are fuel tank connector rings, filler neck retaining rings, zinc die cast spiral and press fit inserts, mounting plates, and many others. 
 
CNC Turning - Screw Machines, and Lathes
Turning is the process in which raw material is held in a rotating chuck/fixture and material is removed with a non-rotating cutting tool. Computer Numerical Controlled (CNC) lathes are programmed to create certain parts and have high replicability and precision. A special type of CNC lathe can be programmed to run continuously, producing high volumes of parts with minimal operator intervention. Rotaloc utilizes CNC Lathes and Screw Machines for the threads on our M1, F1, and F2 Bonding Fasteners, the grooves in our Hex and Square Inserts, cutting the threads and O-Ring pockets on our tank fittings, turning bushings and compression limiters to precise tolerances, and hundreds of other parts.
 
CNC Routing and Milling
CNC Routing and Milling differ from CNC Turning as the raw material is not continuously rotating. With CNC Routing, the material fixture is usually stationary and the cutting tool, which rotates at high speeds, is moved on a gantry to remove raw material. Routers typically operate in 3 axes using the X-Y-Z Cartesian coordinate system. CNC Mills can often have more degrees of freedom compared to routers, as the material fixture moves while the cutting tool is usually stationary. Higher-end CNC Mills, such as the ones used by Rotaloc, operate in 7 degrees of freedom. Meaning the cutting tool and the material move in the X, Y and Z axes (3 degrees) as well as rotating the material about the X, Y, and Z axes (3 degrees) and the rotation and z-axis movement of the cutting tool (1 degree). This allows us to produce a wide array of parts with complex geometry, high precision, and minimal post-processing. 
 
Cold Heading and Cold Forming
Cold Heading, often called Cold Forming, is a process that uses high speed and pressure to shape raw material into a desired shape as designated by the cold forming die. This process is commonly used to form screw and bolt heads but has ample applications with regards to inserts. The word "cold" refers to the lack of applied heat during the forming process as all . Rotaloc produces several inserts that utilize the cold forming process, such as our M1-10.2 bonding fastener, straight knurled hinge pins, button-head pins, and many others. 
 
Deburring and Cleaning
Deburring is the process of removing burrs and sharp edges/corners left over from the manufacturing process. This usually involves submerging machined parts into a tumbler filled with abrasives that rapidly vibrate the parts and removes the sharp features without fully dulling the parts. The parts are then cleaned and inspected to make sure any shavings or bits of excess have been successfully removed from the part, leaving a successfully deburred and cleaned part. Deburring is a crucial process when discussing mold-in inserts, such as Rotaloc's mold-in Hex and Square inserts. Sharp corners can make it difficult for plastic to build up in processes like rotational molding, and this lack of build-up can create weak spots in the final product. By deburring these inserts, we help facilitate better plastic build up on corners and edges. All of Rotaloc's components are thoroughly cleaned and inspected prior to shipping to our customers. The cleaning process involves special ultrasonic solution baths that are part-specific to ensure that parts always arrive without any cutting fluid, metal chips, or debris mixed in. Not only does this improve ultimate moldability, but it can save a lot of money for our customers by reducing the amount of scrapped parts that may have been caused by cutting fluid or mold release agent that was not properly cleaned from the insert. 
 
Etching and Engraving
Etching and engraving, while similar, are very different yet crucial processes that Rotaloc offers. Etching is the process of marking or abrading a surface by use of chemicals or lasers. This is often used to create additional surface texture, achieve a desired surface finish, or to create custom markings on a part. Engraving, which also doable with lasers, usually uses a router or mill that uses a cutting tool to remove material. This is used to cut serial numbers, part orientation or thread indicators, or to create any sort of marking on the surface of a part. This has been used to make marks that aid in orienting inserts when installing, and to differentiate similar-looking inserts that have critically different features, such as thread size. The etching and engraving process can be used to add hatch marks to the bottoms of bonding fasteners to provide extra texture that increases the bond between the insert and the substrate. Engraving can also create knurling on flat surfaces, whereas knurling is usually cut or rolled on a round component using a CNC lathe or screw machine. 
 
Extruding
Extruding is the process of forcing raw material through an extruding die to create a bar of material that has whatever cross-sectional geometry the extruding die defines. This process is commonly used to create aluminum rails with complex geometry that would be fairly difficult or expensive to create via conventional machining. Rotaloc utilizes the extruding process on several of our products for both speeding up production and to provide cost savings for our customers. For large volumes of production parts, an extruding die that has the same cross-section as the final part will substantially reduce the amount of final machining since there's much less material to remove. This process is used both with metals like Stainless Steel, Mild Steel, Aluminum and Brass, but is commonly used in extruding plastic as well.
 
Heat Treating
Heat treating is an additional manufacturing process usually done when the part is fully machined. The parts are heated and cooled in a specific manner depending on the desired outcome and requested specification. The heating and cooling alter certain physical properties of the material, such as impact resistance, hardness, ductility, brittleness, and strength. Certain metals have internal crystalline structures that act more like a liquid at elevated temperatures. By heating these parts, the crystalline structures can realign, and by using rapid cooling, we can "lock in" the desired structure. This is the situation with Case Hardening/Quench Hardening of carbon steel: heating the steel past its critical temperature creates a layer of higher-carbon steel on the outer layer of steel and by quenching (quickly submerging the steel in cooling oil/water to rapidly cool the metal) we can lock in a layer of harder, higher carbon steel in the outer layer. This can increase brittleness, but ultimately improve impact strength. Another process is annealing, wherein parts are heated to their critical temperature and allowed to cool slowly. This allows the crystalline structures to slowly re-disperse throughout the material creating a more homogenous/isotropic material in as well as removing any residual internal/work stress remaining after the machining or manufacturing process. This creates more uniform parts with increased toughness and reduced internal stresses. Heat treating can also increase the surface energy of certain materials, meaning that plastic is more likely to adhere to the inserts during the molding process and can ultimately improve mold quality.
 
Injection Molding
Injection molding is the processes in which molten material, usually plastic or rubber, is forced into a mold cavity by a ram or actuator. The plastic/material quickly cools and is then popped out of the mold by ejection pins. The parts sometimes require some trimming or other post-processing, but it is typically minimal. Injection molding is one of the most commonly used manufacturing processes in the world due to its unrivaled speed, efficiency and accuracy. Depending on quantity and longevity of the project, molds can be made to be practically automated with very little operator interference. This makes injection molding ideal for large volume parts that require high-repeatability. Rotaloc inserts can be installed in injection molds prior to molding to create high-strength metal threads and fasteners to the plastic component.  In addition to providing inserts for injection molding, Rotaloc also provides injection molded parts, such as handles, caps, plugs, wire-tie mounts, and many others in a myriad of industries and products. Our team of engineers and manufacturing experts are well versed in injection molding and can help determine the best insert to get the most out of your injection molding process. 
 
Kitting and Packaging
Rotaloc offers custom kitting and packaging services, from tool kit assemblies and instruction manuals, to reinforced cartons and pallets, to custom box graphics and labels. We are able to produce straight-to-consumer assemblies and products. Our team is here to assist with every step of the process from the initial design, prototyping, PPAP completion, production, packaging, labeling, and finally shipping. Our vast in-house capabilities allow our customers to have an economic, one-stop solution for creating and distributing products from consumer goods to complex components to be used by OEM manufactures. 
 
Knurling
Knurling is the process of adding some sort of patterned ribbing or texture to a surface. This can be done for a multitude of reasons: aesthetics, improving grip, or to improve a mold-in insert's bond to the plastic. Knurling can be achieved through either rolling, cold forming, or cutting. Rolled knurling involves rolling a knurling die against the surface of the material under high pressure. This creates plastic deformation in the material and forces the material to expand and take the form of the die. Cold forming uses speed and pressure to force raw material into a cold forming die, which deforms the material and creates the knurls. Since this is a non-rotating process, this is typically used to create straight knurling. Cut knurls are knurls that are cut or engraved by some machining process- usually a lathe or mill. Cut knurling can be more feasible on ultra-fine knurling, complex or non-round geometry, or when the final knurled diameter is critical. Cold forged or rolled knurls cause the outer diameter to increase since the material is being displaced outwards. Cut knurls are removing material so the original material's diameter remains the same. Rotaloc produces a wide variety of knurled inserts from mold-in tank fittings, to hinge pins, to bonding fasteners with textured baseplates. 
 
Laser Cutting
Laser cutting uses high-powered laser beams to cut through material ranging from thin sheets of aluminum to titanium. Unlike stamping, laser cutting does not require complex tooling or dies and can be used to quickly prototype new parts. Rotaloc's state-of-the-art laser cutting equipment allows us to expedite prototyping and production of custom parts instead of waiting for expensive tooling. Laser cut pieces usually require very little post-processing as there is little to no flashing or burrs left on the cut pieces. 
 
Powdered-Sintered Metal
Rotaloc produces certain parts, like our Geoserts, using a process called sintering. The process starts with a specially designed powdered metal which is pre-impregnated with a special bonding agent. The powdered metal is fed into a mold which undergoes intense pressure to bond the powder to itself. The bonded part is released from the mold and undergoes a final high-temperature cure to finalize the sintering process. The result is a high-pressure, metal component with unique geometry that can be difficult or expensive to achieve with other means of manufacturing, like casting. All of Rotaloc's Powdered-Sintered Metal components and inserts are RoHS, REACH, and 3TG compliant. 
 
Platings, Coatings, and Finishes
Rotaloc offers a wide variety of Platings, Coatings, and Finishes, all of which can be specially tailored to your specific application. Below are a few of the many options we offer, though other options are available. Contact us today to speak with our team to discuss other plating, coating, and finishing options. 
E-Coating
E-Coating involves submerging a substrate in a bath that typically consists of paint, epoxy, or other solutions. An electrical current is applied to the component, which attracts the coating particles that are suspended in the liquid bath. Once the desired thickness is achieved, the coated part is removed and placed into an oven to finalize the coating process (and to improve cross-linking of coating particles, improving coating durability). E-Coating can also be done on top of other platings or coatings, like Zinc-Nickel. This is usually done when the properties of a single coating are not sufficient for an application, as the two coatings can combine their respective corrosion-resistance properties. 
Electroless Nickel Plating
Electroless nickel plating is a deposit of nickel-alloy that is achieved by a process of chemical reduction. Typically, a chemical reducing agent such as sodium hydrophosphite is introduced to the nickel-based solution which reduces the nickel ions to metallic nickel. ENP provides strong resistance to common corrosive materials and environments, such as salt water and hydrogen sulphide. ENP does not utilize the same electrostatic or electroplating process that e-coating and powder coating use. 
Hot-Dip Galvanizing
Hot-dip galvanizing is a multi-step process where iron or steel is immersed in a bath of molten zinc to produce a corrosion-resistant coating of zinc-iron alloy and zinc metal. The process typically consists of Caustic Cleaning (hot alkali solution bath to remove dirt and grease), Rinsing (removes residual solution), Pickling (an acid bath that removes mill-scale to expose raw steel or iron), Rinsing (to remove acid), Flux Solution bath (typically zinc ammonium chloride at 50°-70°C, this removes any oxide film left after cleaning), drying (allows excess solution to evaporate), Zinc Bath (part submerged in bath of >98% pure molten zinc at ~840°F to create zinc coating), and finally Cooling. The final inspection typically involves inspecting and testing sample pieces for evidence of hydrogen embrittlement potentially caused by the pickling process. Galvanizing is a commonly used process given its versatility and corrosion resistant properties. Additional coatings, such as powder coating, can be added on top of the galvanized part. 
Nano-Coating
Nano-coating is an ultra-thin sealant and is typically  ceramic or polymer based solution. The coating fills the pores and micro-cracks in materials and creates a strong corrosion-resistant coating that repels water, dirt, and other corrosives or contaminants. Nano plating can be added to a variety of materials, such as stainless steel, to dramatically enhance the material's existing corrosion resistant properties. 
Painting
In addition to Rotaloc's other plating and coating options, we offer a wide range of painting options. Usually reserved for larger components, our manufacturing team offers flexible options to match color, thickness, and sheen. Contact our team today for information on our painting options. 
Passivating
Passivating is a finishing process that uses chemical baths like nitric or citric acid to remove a small top layer of material and oxidation and then applying a very thin of protective material like metal oxide to create a controlled layer of oxidation that prevents corrosion over time. This can be used to create an aesthetically pleasing and long-lasting finish on metals like stainless steel. Passivation effectively controls and speeds up the natural oxidation process of steel to make the top layer non-reactive to its environment.
Powder Coating
Powder Coating is similar to E-Coating, though powder coating is typically a "dry" process while e-coating is a "wet" one. An electrical current is run through a substrate and a special applicator gun sprays a mist of powder around the part. The electrically charged part attracts the powder from the air, coating the piece. When the desired thickness is reached, the part is baked in a curing oven to set the powder and create the final coating. It is easier to achieve a thicker layer with powder coating than e-coat. Like e-coating, you can combine this process with certain platings and coatings like Zinc-Nickel to combine the corrosion resistant properties of the two finishes. 
Sealants
Rotaloc offers a range of different sealants, such as PMMA and acrylic sealants. Contact our team today to ask about different sealant options for your applications.  
Trivalent Zinc Plating (TZP)
Trivalent Zinc Plating (TZP) is one of the most commonly used plating options for mild-steel components. It greatly improves the corrosion resistance of steel and is one of the most economically viable options for mild or low-carbon steel. All of Rotaloc's steel and TZP components are RoHS and REACH compliant.  
Zinc-Nickel Plating
Zinc-Nickel plating is one of the most common plating options used on mild-steel/low-carbon steel components. 
 
Press-Fitting
Press-Fitting is a method of mechanical binding that does not involve welding or threaded fastening. Press-fit components are typically precision machined to very close tolerances and consist of an internal and external component. The internal component is installed inside of the external component with a high-strength press. With certain materials, the parts may be heated prior to press-fitting to cause them to expand and allow for installation, creating a tight connection as the parts cool and shrink. This is exaggerated when using dissimilar materials with different coefficients of thermal expansion. Press-fitting is beneficial in several applications, such as the ability to join dissimilar metals like brass and stainless steel. Rotaloc produces certain bonding fasteners with stainless steel baseplates and brass collars to more precisely control heat distribution during molding as well as corrosion resistance on exposed installation faces. 
 
Stamping and Bending
Stamping is the process of cutting or reforming flat sheet metal using a stamping press that applies pressure directly into the sheet metal with a specialized tool and a die surface. The type of tool and die used depends on the type of shape is desired, and are usually referred to by the specific process performed, such as coining, blanking, punching, etc. Parts that require several of these operations are made in a progressive stamping die, where the operations occur one after another along a manufacturing line. Bending is a specific kind of stamping process where the sheet metal parts are deformed to create various shapes or to add channels into a part. Since metals that undergo bending are ductile, they tend to spring back a certain amount after being bent. Careful testing and consideration is taken to design the stamping dies so the final product is made to the desired dimensions. Bending and Stamping can recreate parts with unusual geometries at a fraction of the cost due to the low cost of sheet metal and lower cost of tooling compared to other metalworking methods. Many Rotaloc components are made using these processes. The baseplates of our Bonding Fasteners are created using progressive stamping dies to create the weld projections and perforations. Rotaloc's spring clips, bent baseplates, brackets, and clips all undergo bending requiring specially designed tooling.
 
Thread Cutting, Rolling, and Tapping
Threads can be produced in many different manners, which are usually determined by type, length, and size of threads, material, shape of thread profile. Thread cutting is usually done on a screw machine or CNC lathe and cuts/removes material from the bar stock to create the thread profile. Thread rolling produces threads by passing the material through a series of rolling thread dies. This method is typically very accurate and strong as the material's grain structure remains in tact. Rolling also creates a fine surface finish with no machining lines or material waste. Tapping, similar to thread cutting, uses a cutting tool to remove material to cut the threads into the component. Tapping is usually accompanied by a drilling process that precedes tapping. Tapping is used on internal/female threads to cut where standard cutting tooling or roller dies cannot reach. 
 
Testing and Prototyping
Testing and prototyping are a crucial step in the pre-production process. Rotaloc's engineering and quality labs perform a variety of tests to provide additional information  regarding performance and strength expectations of various inserts in different materials and applications. Click here to learn more about our product testing and prototyping capabilities. 
 
Welding
Welding is fundamentally the joining of two materials through the application of heat. Rotaloc has many different welding methods that we utilize to produce our various inserts. Below are of the more common methods used to create Rotaloc inserts and components. 
Laser Welding
Laser welding utilizes CNC machines to focus high-powered laser beams to heat the base material while a separate nozzle deposits the filler material and shielding gas. The result is an accurate, reliable method of welding that can be fine tuned to a variety of materials in different thicknesses and compositions. Laser welding typically produces an aesthetically pleasing weld which is often ideal for components with clear or translucent platings. 
Projection Welding
Projection Welding (often called Profile Projection Welding) is a form of resistance welding where two metal components are joined by being pressed together under an electrical current. The current creates arcs between the parts while the high pressure forces the parts together, melting the two parts together at their joint. Projections are often stamped or machined into the primary component and those projections collapse and melt as the two parts are joined, creating a strong connection with maximum contact area. Projection welding is used on a majority of Rotaloc bonding fasteners to fix the collar, nut, or threaded stud to the baseplate. Additionally, TIG welds can be added to the parts in addition to the projection welds to further increase the torsion or tensile strength. 
TIG Welding
TIG stands for Tungsten Inert Gas and is a method of resistance welding where a current is run through a tungsten electrode to the metal workpiece while simultaneously dispensing an inert gas to prevent rapid oxidation of the molten material. A filler material is laid down in the molten "puddle" created by the electrode and fills the space, creating the weld. TIG welding is a highly controllable process and Rotaloc utilizes state-of-the-art CNC TIG welding machines to create aesthetically pleasing, strong, and consistent welds. TIG Welding can be very beneficial in the early design and prototyping process as bonding fasteners can be prototyped without creating special tooling for projection welding. TIG welding can be used on both thick and thin materials and can be fine-tuned to each application. 
 
Wire EDM
EDM stands for Electrical Discharge Machining, and is a process where a base material cut or machined with a series of small, high-powered electrical discharges applied by a CNC electrode. The part is typically submerged in an electrolyte solution that does not prohibit discharge but allows waste material to be cleared away as the part is machined. This process can be used to cut very hard material, such as tool steel and titanium. The material is not limited by the hardness of the end-of-arm tooling as the "cutting" is done with an electrical charge. This method of machining is commonly used on large, hardened parts such as molds and tooling. 
Wire Forming
Wire forming is the process of feeing wire through a series of rollers and benders to deform and shape wire to the desired shape. Many of Rotaloc's components are created through wire bending, such as our spring clips, S7 (Special) Bonding Fasteners, and Steel Wire-Tie Mounts. Contact Rotaloc today to discuss our various wire forming capabilities and how they can best suit your projects. 
 

Contact Rotaloc Today

The routine use of these processes allows Rotaloc to identify the most efficient means of production for each component or assembly. 
Contact Rotaloc for more information today.