Specification Brand : N. Fasteners BulletPoint1 : [SIZE & PACKAGE]: Our External Tooth Washers have a specification of M8, an outer diameter of 15mm/0.59", an inner diameter of 7.4mm/0.29", a total thickness of 1.3mm/0.05", a material thickness of 0.25mm/0.01". And the packaging includes 20pcs ing washers. BulletPoint2 : [MATERIALS]: These serrated washers are made of 65Mn material, which has high hardness and does not deform. They are suitable for indoor, outdoor, or humid environments, with fine craftsmanship, beautiful appearance, good corrosion resistance, long-lasting strength, and durability. BulletPoint3 : [DESIGN]: washers apply spring force between the fastener head and base, causing the washer to adhere tightly to the base and the bolt to adhere tightly to the nut, resulting in more friction and rotational resistance. Provide a ing effect to ensure tight fit and slip resistance. BulletPoint4 : [EASY TO OPERATE]: Our locking fasteners are very convenient to use. You just need to prepare the appropriate screws, then insert the washers into the screws, and tighten the nuts to complete the assembly. Even beginners can operate seamlessly. BulletPoint5 : [WIDELY APPLICABLE]: Our locking washers are suitable for threaded and bolted connections of various household and commercial appliances, and automotive and marine power supplies. Widely used in mechanical equipment and industrial production for shock absorption and insulation. These multifunctional fasteners provide stable and non-rotating gasket placement for various DIY tasks and electrical repair projects. Color : 50Pcs M20 x 40 ExteriorFinish : Zinc ExternallyAssignedProductIdentifier : 8498202683077 ExternallyAssignedProductIdentifier1 : 0749273263063 ExternallyAssignedProductIdentifier2 : 749273263063 ItemName : 1/2" Zinc Plated Internal Tooth Lock Washers (Pack of 12) ItemPackageDimensions_Height : 0.59 inches ItemPackageDimensions_Length : 3.54 inches ItemPackageDimensions_Width : 2.36 inches ItemPackageQuantity : 1 ItemTypeKeyword : tooth-lock-washers Manufacturer : N. Fasteners Material : zinc plated MetalType : Alloy Steel MetalType1 : Alloy Steel MetalType2 : Spring Steel ModelName : CREAP ModelNumber : 014973187958 NumberOfItems : 20 NumberOfPieces : 12 PartNumber : 12ILWDZ ProductDescription : 1/2" Zinc Plated Internal Tooth Lock Washers (Pack of 12) ProductSiteLaunchDate : 2012-12-10T19:00:13.874Z Size : #4 Style : Internal Tooth SupplierDeclaredDgHzRegulation : not_applicable UnitCount : 20 UnspscCode : 31161807 WasherType : Internal Tooth Lock WasherType1 : Internal Tooth Lock WasherType2 : lock washers