Electromagnet Selection Guide, Electromagnets, electro magnets, electromagnetics

There are many variables that must be considered in the selection of a proper magnet. To help you get the best magnet for your application, we should have the following information:

1. Surface of the work - is it scaly, rough, flat, machined or of irregular shape?

2. Size of the work - give thickness, width, length and weight, plus area of contact for the magnet.

3. Air gap - distance from work surface to face of magnet, whether actually air or non-ferrous material.

4. Composition of the work - hot or cold rolled steel, tool steel, high carbon content steel, nickel, carbide, etc.

5. Heat - temperature in which the magnet will operate and temperature of the work.

6. Duty Cycle - will magnet be on 100%, 50%, or 25% of the time?

7. Method of operation - will magnet be turned on and off manually or automatically? If the latter, how many times per minute?

8. Send prints - or sketches, parts, Polaroid shots and whatever other information will help in selecting the proper magnet.

9. Special note - the economical pick up and transfer of small parts or scrap require a scrap yard type magnet or a magnetic conveyor. Please consult us.

FLAT-FACED MAGNET - used when the entire face of the magnet is in direct contact with the work to be held or lifted and the work surface is smooth and flat. This design usually requires less overall height and is less expensive.

Bl-POLAR MAGNET - has two widely spaced poles or lifting surfaces which cause the magnetic field to "reach out" further. Use the bi-polar type when the magnet has only partial contact with the work piece, to handle an irregular shape, or when it must work through an air gap.

SMALL MAGNETS - generally operate on 12 volts. They will require a rectifier to convert 115 VAC to 12 VDC. Another method of obtaining direct current for magnet operation is through the use of 12 volt batteries.

LARGE MAGNETS - will usually operate on 115 or 220 VDC. A rectifier is required to convert 110, 220, or 440 VAC to 115 or 220 VDC.

TOTAL WATTAGE - of all magnets powered by a single rectifier must not exceed wattage rating for the rectifier, e.g., from one to five 3watt magnets can be used with a 1 5-watt rectifier.

THIN GAUGE SHEET - Magnets to pick up thin gauge, flexible sheet, such as 1/8", 3/16", and 1/4" thick, may require variable power, multiple coil, or special poles to maintain holding power and prevent double sheet pick up. Two or more magnets on a spreader bar of "H" frame may be needed to eliminate "peel off".