These may be confusing but it’s the general guide I use when winding coils.

1. Cohesion is the force that holds together the molecules of the same elementary magnet wire. The greater the temperature of the magnet wire, the less is the cohesion. Malleability, ductility, tenacity, toughness, hardness and elasticity are to be considered properties dependent upon cohesion.
2. Stress is that which causes a strain or deformation in the structure of the material on which it acts.
3. Malleability is the property whereby the molecules of a body may be extended in any direction without rupture by relatively slow compressive stress. Magnet wire is rolled and drawn to it’s desired diameter and then the bare copper wire is insulated to keep the turns from shorting.
4. Ductility is the property of the body whereby its form may be changed by the action of pressure-the property whereby a metal may be drawn into a wire.
5. Tenacity is the greatest longitudinal stress that magnet wire can withstand without rupture.
6. Toughness is the resistance to fracture offered by a material when it is repeatedly bent or twisted.
7. Hardness is the resistance offered by the molecules of a copper wire to their separation by the penetrating action of another body.
8. Brittleness is the sudden failure of cohesion between the molecules of the magnet wire when it is wound into the desired coil shape.
9. Elasticity is the property of the magnet wire whereby it resists deformation under stress and resumes its original for when the stress is removed.