This chuck has poles of 1/8" magnetic steel and 1/8" nonmagnetic stainless steel. The top plate is furnace brazed, making a solid, one piece unit.

It can be drilled or machined to a depth equal to the thickness of the top plate minus 1/8". Machining can be done between poles or anywhere in the top plate except where the screws secure the plate to the base. The magnetic circuit allows excellent holding of thin work as well as the power necessary to hold large work pieces.