Flexible Magnet Thickness Guide (15 mil to 60 mil)

Flexible magnetic sheeting is available in multiple thicknesses, typically ranging from 15 mil to 60 mil and beyond. Selecting the correct thickness is essential for achieving reliable holding strength in signage, printing and industrial applications.

What Does “Mil” Mean?

A mil is one thousandth of an inch (0.001"). For example:

  • 15 mil = 0.015 inches
  • 20 mil = 0.020 inches
  • 30 mil = 0.030 inches
  • 60 mil = 0.060 inches

As thickness increases, magnetic strength generally increases.

How Thickness Affects Pull Strength

Thicker magnetic material contains more magnetic compound per square inch, increasing holding force when in full contact with steel.

  • 15 mil – Ultra-lightweight applications
  • 20 mil – Light-duty graphics and promotional items
  • 30 mil – Standard vehicle signage
  • 40 mil – Enhanced holding performance
  • 60 mil – Heavy-duty or high wind applications

Actual performance depends on steel thickness, surface flatness and air gaps.

Common Applications by Thickness

15–20 mil

Business card magnets, direct mail promotions, lightweight POP displays.

30 mil

Standard vehicle magnets and removable fleet signage.

40–60 mil

Larger vehicle graphics, high wind exposure and heavier signage installations.

Important Performance Factors

  • Clean, smooth steel surfaces
  • Adequate steel panel thickness
  • Temperature conditions
  • Wind exposure for vehicle use
  • Full surface contact

Even thicker material may underperform if installed on thin, curved or contaminated surfaces.

High Energy vs Standard Grade

In addition to thickness, high energy flexible magnetic materials provide increased magnetic strength without increasing material thickness. This can be beneficial when weight or flexibility must be maintained.

Need Help Choosing the Right Thickness?

Explore our Flexible Magnetic Sheeting or visit our flexible magnetic materials in Canada page for a complete overview.

For installation guidance, see our vehicle magnet best practices guide.

If you are unsure which thickness is appropriate for your application, our team can provide technical guidance.

For application-specific recommendations, see our magnetic solutions for vehicle graphics & fleet page.