M4 Carbon Steel Flat Washer, Black Oxidized Alloy Steel, 4.8 Grade Metal Flat Washer, 4mm ID, 9mm OD, 0.8mm Thickness, 500Pcs

Made of widely used carbon spring steel with higher strength, hardness, elasticity and hardenability. | Size: 4mm/ 0.15" inner diameter, 9mm/ 0.35" outer diameter, 0.8mm/ 0.03" thickness. | Flat washers evenly distribute pressure not only on the nut but also on the head of the fastener. | The washer prevents damage to the material and reduces the possibility that the nut will come loose from uneven surfaces. | Package Included: 500Pcs M4 Steel Flat Washers.