flap wheel 1.Size: 4". 2.usage:Grinding metal,welding line,stainless steel. 3.Own brand:Shengyan. Abrasive flap disc 1)Name:K51 flap disc calcined corundum,grinding welding line,sanding disc2)Fabric:K51 cloth3)Material:Calcined corundum/brown fused alumina.4)Advantage:Grinding welding line. 5)Application fields:Stainlness steel,metal,wooden,hardware factory.