How to Properly Use a Magnetic Squaring Block / Chuck

MSB6x61Using a magnetic squaring block (magnetic squaring chuck) is the most accurate and quickest way to square parts on a surface grinder. The magnet will hold the workpiece without distortion that will be caused by mechanical clamping, while release/clamp time is significantly reduced.

To get the finest results from a squaring block, correct setup is vital. Here are key steps in the process.

  1. Check that the magnetic chuck on the surface grinder is flat and nick free.
  2. Grind the first side of your workpiece flat.
  3. Mount the magnetic squaring block (MSB) with the on/off switch on the right side and hardened rail on the left.
  4. Place a support block near the lower left corner of the MSB.
    • We like to use a block with a button head screw in the top so the part rests on the top of the screw. The screw allows you to adjust workpiece height to extend beyond the top of the MSB.
  5. Turn on the magnetic chuck on the surface grinder
  6. To mount your workpiece, place ground side on against MSB. Slide the workpiece against the rail and down to the support block.
  7. Turn on the MSB.
  8. Grind the first side.
  9. Turn off the MSB.
  10. Clean both the workpiece and MSB.
    • We do not use the air hose here, we wipe the contact surface with our bare hand
  11. Follow previous steps, placing the last ground surface against the rail.

This will accurately square up the two sides you ground to the third side you located from. When removing the MSB from the surface grinder, care should be taken to not slide the MSB.

  1. After demagnetizing the surface grinder magnet, apply force at the top of the MSB to break any residual magnetism and surface tension
  2. Lift the MSB straight up
  3. Clean and oil the MSB

Get the Most from Your Hermann Schmidt Precision Tools

At Hermann Schmidt, we offer two models of magnetic squaring blocks. For most high-precision squaring operations, Our standard pole 6-inch Magnetic Squaring Block delivers a quick and extremely accurate method of grinding blocks square. Our 4-inch Fine Pole Magnetic Squaring Block is a fine pole, low profile magnetic chuck designed for fast and precise squaring up of smaller parts.

Following our guide to using magnetic squaring blocks will help you get the most out of your tools.

UPDATE:  Question was asked to see some setups.  The following is a couple of pictures of a work piece set up on the 6″ squaring block.  The top of the stop in the 123 block has a radius on it so the work piece is sitting on a point.

001  002

Magnetic Squaring Blocks