Anomalous mode-converting reflection of elastic waves using strip-type metagratings

•A novel metagrating for simultaneous realization of mode-converting and anomalous steering of elastic wave reflection is proposed.•Near-perfect mode-conversion efficiencies are achieved for in-plane waves in thin elastic plate.•Metagratings realize longitudinal-to-shear and shear-to-longitudinal wave mode conversions in scattered refection field.•Higher-order scattered diffraction modes are effectively and selectively suppressed in metagratings.