hollow grouting anchor bolts. plate. nut,bits,Coupling. Hollow Grouting Anchor BoltsType:R25,R27,R32O.D.:25mm,27mm,32mmTensile Strength:≥150,≥180,≥230Thread type:LeftAccessories:Plate,Nut,Stop-grouting plug,anchor bits R27 Hollow Grouting anchor bolts