manufacture of the finest mass finishing equipment and supplies in the marketplace.
Parts that are manufactured usually need removing of jagged edges, cleaning and polishing before they are fit to satisfy their functionality (the function for which they are being built). This is achieved by means of a process called finishing. Mass finishing is several parts being finished all together. It is typically carried out in finishing machines or systems like tumbling machines, vibratory machines, blasters, centrifugal machines etc. Parts are fed into these machines along with finishing media, finishing compounds and water. The parts and the finishing media scrub against each other, with the compounds aiding in removing the debris and keeping it from re-depositing on the parts. Due to this scrubbing action, mass finishing takes place - edges are smoothed, surfaces get polished, nooks get cleaned and parts get broken from runners.
Finishing media are materials that aid in the mass finishing process. There are many types of media like synthetic pre formed plastic media, ceramic media and natural media like corn cob and walnut shell media. Finishing compounds could be dry or wet and depending on the action required, their composition varies. This determines their abrasive action, alkalinity etc. Mass finishing process can take place as a batch process, as a series of steps or as continuous process. In a batch process, parts are loaded as a batch and after finishing, the batch is unloaded. The next batch now goes in and so on. In the step by step process, the parts are taken through a sequence of processes, one by one. After every step, the parts will have some degree of finishing done on them and after the final step, they will be fully ready. In a continuous process, the loading and unloading of parts happens continuously, while the finishing process is carried out.
Walnut shell media are made from treated and crushed walnuts. As they are natural, they are bio degradable and safe for the environment. They are dry finishing media whose grain size is determined by the weight and composition of the parts being finished. They are very good cleaners too apart from being good polishers. They are suited for use with tumble machines and useful in finishing of parts made from soft metals like brass, aluminium and bronze. Mixed with paints, they act as anti skid agents and are typically used in paints used around swimming pools and pathways. Oil well drilling is another area where they are used, to prevent the oil from stagnating.
Walnut shells have the properties of hardness and fibre. They are also naturally angular and multi faceted, which makes the walnut shell media ideal for deburring. They last long and can be reused many times over. Used in tumbling and in some vibrating systems, they help to reduce cycle times. They can be used on delicate surfaces because they do not have a rough abrasive action. So, they do not damage micro finishes. There are companies who have been in the finishing business for a long time; they can find finishing solutions for any needs. To learn more visit http://gravcollc.com/
Posted 10 months, 3 weeks ago at 8:44 pm. Add a comment
Ceramic media are materials used in the finishing process to aid in deburring, polishing, separating and cleaning of parts. They can be used for light as well as heavy deburring, fast deburring and rough metal removal. They are best suited for hard metals heavy cutting requirements. When small sized media are needed (around three fourth of an inch size), ceramic media has the best options. They can be used even for very heavy metal parts effectively. They are made out in different shapes like angle cut cylinders and triangles, cones, straight cut triangles, cylindrical wedges and angle cut tristars and ellipses.
Ceramic media are long lasting, cheap and can be put to multiple uses. They are manufactured in a variety of shapes that are precise and which prove very useful in preventing lodging problems and also in separating parts. They are made primarily with silica. Other materials in the manufacture of ceramic media include minerals and abrasives. Silica, minerals and abrasives are combined in different proportions and treated at a high temperature to produce a very hard product that is as strong as a cement product.
Ceramic media of varying density is used for different purposes. Where a rough finishing is needed (fast cutting and rough surfaces), higher density ceramic media is used. For smoother finishing, lesser density ceramic media is ideal. Higher the proportion of the abrasive material used in the manufacture of ceramic media, higher is the density. Higher the density, quicker is the wear and tear. There fore, higher density ceramic media should be considered only for special cases and when there is a need for cycle time reduction. To aid in special finishing requirements, the ceramic media can be tailored by changing the type and amount of abrasive grain used.
The fastest available option for mass finishing of parts is the centrifugal barrel machines. Their cycle times are 20 times faster compared to vibratory finishing machines. The centrifugal barrel machines have large barrels for loading parts, media and finishing compounds. They are high energy machines. In a typical centrifugal machine, there is a turret at the centre. A set of barrels are placed around the turret. When the turret starts rotating in one direction, they set the barrels rotating in the other direction. Thus a high energy sliding action is produced inside the barrels, imparting a uniform finish to the parts. Barrels are normally made of steel; sometimes they are made from composite materials too. They have polyurethane lining and can be removed during the loading and unloading process. Steel barrels are meant for cycle times exceeding one hour; for cycle times less than an hour, composite barrels are ideal.
Centrifugal barrel machines come with process timers that can be set for specific finishing jobs. There is an emergency stop switch that can be used in crisis scenario. Indicator lights and safety locks are generally provided to ensure control and safety. Wiring can be done for different electrical voltage settings. To explore options in centrifugal barrel machines and ceramic media, visit http://gravcollc.com/
Posted 10 months, 3 weeks ago at 7:55 pm. Add a comment
Tumbling media are materials that are used in the finishing process. They are loaded with parts to be finished into finishing machines, with or without tumbling compounds. They help in cleaning, smoothing and deburring of parts. Tumbling media can be man made or natural. Man made media include plastic media, synthetic media and ceramic media which come in preformed shapes. Natural media include walnut shell media and corn cob media. Tumbling media are used in finishing machines like tumbling barrels, vibratory machines and centrifugal machines.
Plastic media are otherwise known as tumbling stones. They come in shapes like cones, pyramids and triangles and have varying abrasive properties. They create smooth but dull finishes on surfaces and because of their light weight are suited for use on parts that might get damaged easily. They are safe on threaded parts and can be used on parts as a pre cursor to anodizing. The cone shaped plastic media act well on parts with holes and triangle shape acts well on edges and flat surfaces. Multiple shapes can be used on parts with complex designs.
Ceramic tumbling media are made of silica, minerals and abrasives mixed in different proportions and processed at high temperatures to produce hardened shapes. They are good for aggressive finishing needs and work well with hard metal parts. They suit usage with heavy loads that cannot be handled by plastics; they also come in smaller sizes and hence are suited for smaller parts. Synthetic tumbling media also come in different shapes; they weigh lesser compared to ceramic media. They are cost effective and are good to provide ultra smooth finishes. Compared to plastic media, they take more wear and tear and residue left from processing is lesser. They are ideal for use in high energy machines like centrifugal barrels.
Tumbling compounds are chemicals used to increase the effectiveness of media by ensuring that glaze is not formed on the parts during the finishing process. They act as abrasive agents and help in maintaining a nice color to the metal parts. They impart anti rust and anti corrosion properties to the parts when the right agents are added to them; they are effective cleaning agents and help in deburring by suspending debris and preventing them from getting re-deposited on the parts. The compounds are either alkaline or acidic in nature depending on the media they are used with.
The flow rate of the tumbling compounds should be matched with the volume of media being used for a good finish. Tumbling compounds are known to help in degreasing, descaling and removing grime. They help in lubrication of parts to protect them. They help in grinding, polishing and brightening of surfaces. They help to finish delicate parts by providing a cushioning effect and preventing damage to the parts. Acidic tumbling compounds enhance cutting speeds and bleaching efficiency. When used in proper combination with finishing media, tumbling compounds help to reduce cycle times substantially. To learn about the advantages of tumbling media and tumbling compounds, go to http://gravcollc.com/
Posted 10 months, 3 weeks ago at 7:42 pm. Add a comment
Deburring is the process of removing jagged edges or protrusions from parts, mostly wooden and metal parts. Deburring machines are used to accomplish the process of deburring. Primarily two types of deburring machines are used – tumbling or barrel machines and vibratory machines. Tumblers are used for mass finishing of parts. They can be used for wet as well as dry finishing. These systems are well suited for fast and efficient deburring of plastic and metal parts or components. There are models that are available in different sizes from compact bench models to big barrels that can be fixed on floors. Tumbling systems are very important deburring systems in use. They are typically used where heavy deburring is required. Barrels are ideal for heavy loads. Dry tumbling is used when delicate deburring is called for and produces a smooth finish. Wet barrelling is used for metal processing to remove excess material as well as to provide a polish.
Vibratory deburring machines are also used for mass finishing. They function by shaking or vibrating the processing vessel, which causes the finishing media and parts to scrape against each other thus accomplishing a deburr and producing a polish. These deburing machines are precise and can deburr even recesses in the parts and hence they are very well adapted for delicate and intricate components. They can also be used on large surfaces because they have very short strokes and high speeds. These machines can be automated quite easily compared to tumblers.
Blasting machines are another type of deburring machines in which media is blasted on to parts under high pressure thus creating a finishing action. Blasting machines are used to deburr hard to reach parts and also to clean parts of dust, grime, rust etc. There are also other deburring machines like gyra machines, centrifugal disks and spin finishing machines for specialized usage.
Finishing media are used in finishing systems to aid in the deburring process. Ceramic media is ideal for use with hard metals that need heavy cutting action. They are generally used for polishing and deburring – light, heavy, fast or super fast deburring. For applications that need small sized media, ceramic media is highly recommended. They come in pre formed shapes to suit different purposes. Cones, stars, triangles, cylinders etc are some of the shapes in ceramic media. These shapes ensure easy separation of parts and deburring of hard to reach areas. Ceramic media are long lasting and inexpensive. As they can be used for multiple requirements, they are the most commonly used in the mass finishing industry.
Ceramic media are made as a combination of silica, minerals and abrasive materials and are manufactured at very high temperatures thus producing hard ceramic media which are then cut to the desired length. The rougher deburring applications call for a ceramic media that has more density. By using more abrasive in the manufacturing, high density can be achieved. But high density means faster wear and tear; so they are used only rarely. Go to http://gravcollc.com/ for more information on deburring machines and media.
Posted 10 months, 3 weeks ago at 8:59 pm. Add a comment

David Scheetz is principal owner and CEO and Robert Summey is Sales manager. These two together bring over fifty years of metal finishing experience to Grav Co LLC.
Grav Co LLC manufactures the finest mass finishing equipment and supplies in the marketplace. We build Torex vibratory finishing machines, deburring machines, Grav-i-Flo disc finishing, high speed and low speed barrel finishing, tumbling barrels, centrifugal barrel machines and spin finishing equipment in our Sturgis, Michigan plant. We also manufacture vibratory finishing media, corn cob media, plastic deburring media, walnut shell media, and various liquid and tumbling compounds, and have a very good line of ceramic finishing media.
The trade name Grav-i-Flo has been synonymous with quality finishing equipment and supplies for over sixty years. We are able to provide you a quote on standard equipment, and supplies in one day or less. We ship most supply orders in one to two days. We are a world class supplier of finishing equipment and supplies.
New Products
A new product line currently on the drawing board is standard parts washers. We are building a cellular style belt and rotary drum washers. If you have a parts washer project currently that you think a simple belt or drum washer will suffice, we build a very good washer at a very competitive price. Try us, I think you will like the products and our team. Let us help you resolve your finishing needs.
Posted 10 months, 3 weeks ago at 5:45 pm. Add a comment