MM-D-20 - Neodymium Female Stud Mounting Magnet - 20mm Dia

• Dimensions:
      D=20mm (0.79")
      d=4mm (0.16") (M4 Coarse Female threaded stud)
      H=15mm (0.59")
      h=7mm (0.28")
      M=7mm (0.28")
• Material: NdFeB, Grade N38
• Plating/Coating: Ni-Cu-Ni (Nickel)
• Magnetization Direction: Axial (Poles on Flat Ends)
• Weight: 0.56 oz. (15.9 g)
• Pull Force: 28.7 lbs
• Surface Field: N/A
• Brmax: 12,600 Gauss
• BHmax: 38 MGOe

The MM-D style is a flat mounting magnet with a female threaded shaft permanently attached. If you need a magnet to attach to something threaded, this is what you need.