The "pole spacing" (the distance between the steel poles and the non-magnetic separators) determines the depth and distribution of the magnetic field.
Choose "Standard" Pole Spacing if:
• Your parts are thick (typically 0.375" [3/8"] or thicker): Standard spacing (wider poles) throws the magnetic field loop higher and deeper. This provides maximum holding force for larger, thicker plates or blocks.
• You are doing general-purpose milling or grinding: This is the best "all-around" choice for average machine shop work where parts are substantial.
Choose "Fine" Pole Spacing if:
• Your parts are thin (less than 0.375"): Fine poles keep the magnetic field shallow and concentrated near the surface. This prevents the magnetism from penetrating all the way through a thin part (which weakens the hold and magnetizes the table beneath).
• You need to prevent "dimpling": On very thin parts, standard poles can pull the material down into the gaps between poles, causing the part to warp or "dimple." Fine poles provide more uniform support to keep thin parts flat.
NOTE: 0.375" thick is a general rule of thumb, material composition, and other factors may make this differ.