While both types of chucks provide excellent workholding, the choice depends on your specific application, the size of your workpieces, and the level of control you need. Choose an Electromagnetic Chuck if: You need Variable Holding Power: Paired with a Magna-Lock controller, you can adjust the magnetic force. This is critical for "shimless" grinding or when you need to straighten warped plates by starting with low power and gradually increasing it. You need to hold Large Workpieces: For large surface grinders or milling tables, electromagnetic chucks are superior because they don't require physical effort to turn on/off. You need Automated Demagnetization: Our controllers feature automatic demagnetization cycles, ensuring the part releases cleanly and is easy to remove without residual magnetism. Choose a Permanent Magnet Chuck if: Heat is a concern: Permanent magnets generate zero heat. If you are doing high-precision grinding where even slight thermal expansion could affect tolerances, a permanent chuck is the best choice. Portability is required: Since they don't require power cables or a control unit, permanent chucks are easy to move from one machine to another (e.g., from a mill to a surface grinder). You want "Fail-Safe" holding: Permanent chucks do not rely on electricity. If your shop loses power, the chuck will not release the part.

The choice depends primarily on the size and thickness of the parts you intend to grind. To hold a part securely, it must bridge across at least two poles (a North and a South pole) to complete the magnetic circuit. Check out our solutions finder to search for the right chuck for your application. Choose a Transverse (HG/HR/HU) Pole Chuck if: You are holding small or thin parts: The poles run across the width of the chuck (front-to-back). This configuration typically offers tighter pole spacing, making it easier for small parts to span multiple poles. You need a "General Purpose" chuck: Transverse chucks are generally more versatile for job shops that handle a wide variety of part sizes. You are loading the chuck with many small items: It allows for flexible loading arrangements across the width of the chuck. Choose a Longitudinal (HL) Pole Chuck if: You are holding large, thick plates: The poles run the full length of the chuck (left-to-right). This is ideal for large workpieces that cover a significant surface area. You need maximum stability for heavy grinding: For heavy stock removal on large parts, longitudinal poles can offer very stable holding power as long as the part covers the poles adequately. Pro Tip: If you have a Transverse chuck but need to hold a very small or irregular part that won't bridge the poles, you can use Magna-Lock Transfer Parallels or blocks to help direct the magnetic flux through the workpiece.

It is important to distinguish between the input power going to the controller and the output power going to the chuck. 1. The Chuck (DC Output): Our standard electromagnetic chucks require Direct Current (DC) to operate. The two standard operating voltages are 115 VDC and 230 VDC, with a 10% variance being acceptable. Crucial Note: You cannot plug an electromagnetic chuck directly into an AC power source. It requires a Chuck Control unit to convert the AC power into the required DC voltage. 2. The Controller (AC Input): The Chuck Control unit takes standard shop AC power as its input. Depending on the specific model, our controllers can be configured for 115 VAC, 230 VAC, or 460 VAC. Always verify with our team what your AC voltage is prior to ordering or servicing a controller. How to check: Always refer to the nameplate on your chuck. It will list the required DC Voltage (115 or 230) and Wattage. Your control unit must be set to match this DC output voltage and have a wattage rating equal to or higher than the chuck's requirement.