coal pick
3.The results indicate that a stable deformation localization band occurs in the coal cutting course and develops to macroscopic crack; the deformation localization band is slantwise; while the cutter tooth is used, the deformation localization develops slowly, and the localization becomes wider and the strain value in the band area higher afterwards; when the point-attack pick used the localization develops quickly and the localization band becomes narrow and the strain value in the band lower.
