Explosion-proof hoist hoist brake difference with the ordinary

Although there are explosion-proof electric rope hoist  electric hoist single electric hoist brakes and brake CD1/MD1 still there is a big difference, explosion-proof electric hoist brake parts appear worn with friction gasket thickness up to 50% of the original thickness, cracks or spring plastic deformation of the small diameter shaft or wear up to 5% of the original diameter, the above three cases should be scrapped. Brakes for you to explain the difference between the following lies:
1 explosion-proof hoist brake band should be articulated,manual hoist not with bolts, riveting, welding and other forms of rigid connection.
2, the brake wheel surface roughness of 1.6,wire rope winch the surface hardness of HRC40 ~ 45.
3, the brake wheel center line and the center line of the stopper Concentricity 0.030mm.
4, proof hoist brake wheel and brake band brake contact area with the area of not less than 75%.