Specification Brand : uxcell BulletPoint1 : Fastener Type: Hex Serrated Flange Nut BulletPoint2 : Thread Diameter: M10; Thread Pitch: 1.5mm; Flange Diameter(A): 21mm/0.83" BulletPoint3 : Width Across Flat Size (B) : 15mm;Nut Height (M) : 9.8mm BulletPoint4 : Made of stainless steel 304, corrosion-resistant and durable to use. BulletPoint5 : Self-locking serrated flange digs into the material being fastened to help prevent loosening. Color : M6 (Head 25mm) DriveSystem : External Hex ExteriorFinish : Stainless Steel ExternallyAssignedProductIdentifier : 8880486343349 FinishType : silver GpsrSafetyAttestation : 1 ItemName : uxcell M10 Serrated Flange Hex Lock Nuts, 304 Stainless Steel, 4 Pcs ItemPackageDimensions_Height : 14.732 centimeters ItemPackageDimensions_Length : 1.016 centimeters ItemPackageDimensions_Width : 9.906 centimeters ItemPackageQuantity : 1 ItemTypeKeyword : flange-nuts Manufacturer : uxcell Material : Stainless Steel MeasurementSystem1 : Metric MeasurementSystem2 : Inch MetalType : Stainless Steel ModelNumber : a18092200ux0076 NumberOfItems : 1 NumberOfPieces : 4 PartNumber : a18092200ux0076 ProductDescription : A flange nut is a nut that has a wide flange at one end that acts as an integrated, non-spinning washer. This serves to distribute the pressure of the nut over the part being secured, reducing the chance of damage to the part and making it less likely to loosen as a result of an uneven fastening surface. The flange may be serrated to provide a locking action. The serrations are angled such that they keep the nut from rotating in the direction that would loosen the nut. Because of the serrations they cannot be used with a washer or on surfaces that cannot be scratched. The serrations help in avoiding vibration of nut and increase the holding power of nut.