Magnet Shape: Ring with Cylindrical Borehole (Hole)
Material: Sintered Hard Ferrite (Ceramic) and Steel
Coating: Nickel (Ni)       
Grade(Chinese Stardard):         Y30H-1
Magnet ID:            FPCB-18-Y30H-Ni
Detailed magnetic properties data:
Residual Magnetic Flux Density (Br): 3.8-4.0 KGs (mT):  380-400 mT
Intrinsic Coercivity Force (Hcj):    2.89-3.46 KOe    230-275 KA/m
Coercivity Force (Hcb):              2.95-3.64 KOe    235-290 KA/m
Energy Density (BH)max:              3.3-3.8 MGOe     27.0-32.5 KJ/m³
Operating Temperature:               -40 °C to +250 °C
Magnetisation Direction: Axial / Radially magnetized
Pot Magnet Size:
Pot Diameter (D):  18 mm
Pot Height (H):    5 mm
Borehole  (d1):    3,5 mm
Borehole  (d2):    6,5 mm
Depth      (t):    3,8 mm
Tolerance:         +/-2% mm
Delivery time           7-25 days
Measurements

The permanent pot magnets (magnet pot or magnetic pot) position ferromagnetic items quickly and easily in the required place. These magnet systems have only one surface of magnetic attraction. In other words, all the other sides are non-magnetic. This form of construction restricts the further spread of the magnetic field. As a result, other items or machine parts in the vicinity of the pot magnet do not become magnetised.
Pot magnets retain their magnet force indefinitely. Only increase in temperature and external magnetic fields can reduce their magnetic force.