Although it has the appearance of solid metal, neodymium actually behaves more like a ceramic and can crack/chip. Do not use in shallow or rocky waters.  Consider our anti-collision magnets if you target these areas. WE ARE UNABLE TO REPLACE MAGNETS WHICH CHIP OR CRACK DURING USE, AS THIS IS AN INHERENT RISK OF MAGNET FISHING. Heat above 160° F can permanently demagnetize your magnet. Large magnets have a very strong attractive force and improper handling could cause severe pinching/crushing injury. Use caution! Neodymium magnets are not toys. Keep away from children. Pacemakers and other sensitive electronics can be adversely affected by strong magnetic fields. If you wear a pacemaker, do not handle strong magnets. If you are using magnets to hang heavy objects, choose a weight rating that greatly exceeds the object to the hung. Our weight ratings are based on ideal conditions. Surface conditions and metal thickness greatly affect magnet capacity.