Feed and Grain is one of the oldest, and most well documented applications for screw conveyors. It is estimated that up to 60% of the total screw conveyor market is in feed and grain and with the explosion in new feed mill builds over the last ten years, this number is growing. Screw Conveyors are used in every part of the feed and grain industry. From screws on the harvesters to truck unload screws at the receiving stations to bin unload screws at the bottom of feed mixers to screws moving feed to various parts of the mill, the screw conveyor is an integral part of the feed and grain industry.
The screw conveyor is perfectly matched to the needs of the feed and grain industry. It is a compact, highly versatile bulk material handling conveyor. The standard screw conveyor components, as outlined in most screw conveyor manufacturer’s catalogs (Click here for screw conveyor manufacturer’s catalogs), are very well suited to almost all feed and grain applications. These catalogs outline standard configurations of parts with various thicknesses available for high wear items like screws and troughs. Hanger bearings are used widely in the feed and grain industry to allow screw conveyors to span long distances using standard and stock components and are available in a wide variety of configurations and materials to extend the life of this critical wear items. In fact, the CEMA screw conveyor standards all manufacturer’s catalogs are built around are based on the designs developed in feed and grain in the early part of the 1900s. The best part for the consumer is these parts are made in bulk by many manufacturer’s and are therefore stocked and ready for immediate shipment and are priced only slightly higher than the raw steel used to build them.
Below are some of the good, better and best selections for a few common upgradable screw conveyor components in feed and grain.
Design – The formulas and speeds published in most screw conveyor manufacturer’s catalogs are very appropriate for feed and grain. Going much faster is very common for grain and trough loading at 45% and up is the norm. Below are typical examples of speeds considered good, better and best. It should be noted these ratings are considered based on wear and longevity of the parts.
| Trough Loading | Screw Diameter | Good Speed | Better Speed | Best Speed |
| 45% | 9″ | 1.3 x Best | 1.1 x Best | 155 RPM |
| 10″ | 1.3 x Best | 1.1 x Best | 150 RPM | |
| 12″ | 1.3 x Best | 1.1 x Best | 145 RPM | |
| 14″ | 1.3 x Best | 1.1 x Best | 140 RPM | |
| 16″ | 1.3 x Best | 1.1 x Best | 130 RPM |
Screws – The main upgradable feature to extend the life of the screw in feed and grain is the thickness of the fighting. Below are typical examples of thicknesses considered good, better and best. It should be noted these ratings are considered based on wear and longevity of the parts.
| Screw Diameter | Good Thickness | Better Thickness | Best Thickness |
| 9″ | 1/8″ | 1/4″ | 3/8″ |
| 10″ | 1/4″ | 5/16″ | 3/8″ |
| 12″ | 1/4″ | 5/16″ | 3/8″ |
| 14″ | 1/4″ | 3/8″ | 1/2″ |
| 16″ | 1/4″ | 3/8″ | 1/2″ |
Troughs – The main upgradable feature to extend the life of the trough in feed and grain is the thickness. Below are typical examples of thicknesses considered good, better and best. It should be noted these ratings are considered based on wear and longevity of the parts.
| Screw Diameter | Good Thickness | Better Thickness | Best Thickness |
| 9″ | 14 GA | 12 GA | 3/16″ |
| 10″ | 14 GA | 12 GA | 3/16″ |
| 12″ | 10 GA | 3/16″ | 1/4″ |
| 14″ | 10 GA | 3/16″ | 1/4″ |
| 16″ | 10 GA | 3/16″ | 1/4″ |
Hanger Bearings – Changing the material of construction is the best way to get more out of a screw conveyor hanger bearing. There is a great article about selecting the best hanger bearing here. Most feed and grain applications use wood hanger bearings and then move to some exotic plastic for more life and bronze and ball bearings for high speed applications.