Note: Charts for machine screw jacks, machine screw ComDRIVEs®, metric screw jacks, ball screw jacks, ball screw ComDRIVEs®, stainless steel jacks, bevel gear jacks, and bevel ball actuators are located within the specific product section of the catalog. These charts only apply to jacks with axial loads. For side loads, offset loads, and horizontal mounting, contact Joyce/Dayton.
- Determine the type of jack you wish to use and locate that column load chart.
- Determine the proper mounting configuration for your application. Locate the appropriate row and find the screw length at the bottom of the chart.
- Find the load you need to move (in pounds or kilonewtons) on the left side of the chart.
- Find the point on the chart where the load and length intersect. Choose a jack whose line is on or above this intersection.
- Add the length of the end condition you have chosen and any additional screw extension to the screw length to find the "unbraced" screw length. Verify your selection using the unbraced length.
Example:
A jack must lift 5 tons (10,000 pounds) over a distance of 31 inches. The load places the screw in compression. The jack is mounted firmly by its base, and the load is attached to a load pad (Type 2 end) and is not guided.
- In this example, a machine screw jack will be used so review the Column Loading chart for machine screw jacks.
- Look at the "unguided" row at the bottom of the machine screw jack Column Loading chart and find the 31" mark.
- From this, the 10-ton double lead jack is selected. Look at the dimensions from the jack body for the Type 2 end for this jack. The Type 2 end adds 2" from the top of the jack to the end of the screw. Thus the total unbraced length of the screw is 31" + 2"= 33".
- Use this new unbraced screw length to verify your selection. In this case, the intersection point still falls below the 10-ton double leadjack line, so this selection is correct.