Specification Brand : HHIP BulletPoint1 : Made of high grade tool steel. ~ Hardened and precision ground BulletPoint2 : Meets or exceeds Federal specifications BulletPoint3 : Major diameter is .830" BulletPoint4 : Overall length is 1.230" BulletPoint5 : Collet must be placed into collet chuck nut before inserting into collet chuck Capacity : 0.83 inches Color : Black CompatibleDevices : Milling Machine CompatibleDevices1 : Drilling Machine CompatibleDevices2 : Lathe CompatibleDevices3 : Milling Machine CompatibleDevices4 : Grinding Machine DriveSystem1 : Slotted DriveSystem2 : External Hex ExteriorFinish : Special Coating ExternallyAssignedProductIdentifier : 6111622381959 ExternallyAssignedProductIdentifier1 : 769053028323 ExternallyAssignedProductIdentifier2 : 0769053028323 ExternallyAssignedProductIdentifier3 : 00769053028323 FinishType : Coated GradeRating : industrial ItemName : HHIP 3900-5185 ER-20 Spring Collet, 1/4" ItemPackageDimensions_Height : 3.4036 centimeters ItemPackageDimensions_Length : 2.0066 centimeters ItemPackageDimensions_Width : 2.0066 centimeters ItemPackageQuantity : 1 ItemTypeKeyword : workholding-collets LockType : Independent Manufacturer : HHIP Material : Alloy Steel MaximumShearStrength : 75+ ft/lb MetalType : Alloy Steel ModelNumber : 3900-5185 NumberOfItems : 1 PartNumber : 3900-5185 ProductDescription : The maximum torque is laser marked on the ER collet nut face to take the guess game out of the way to ensure proper amount of force should be applied while tightening. Innovative coating process significantly increases the clamping force by 75% compared to standard ER collet nut. More gripping force provides better rigidity and reduces the possibility of losing grip on the round shank which lead to expensive damage on cutting tools and work piece material. Internal clamping ring's shape is design to minimize out-of-balance compare to the standard off-center o-ring design from other standard ER collet nut, achieving 12,000 RPM without needed to drill holes on the collet nut body when placed on a dynamic balanced machine to preserve ER collet nut's body strength. Slot geometry is design with different length to offset uneven weight distribution from the inner o-ring.The face of the ER collet nut is precision ground to achieve visual appeal. ProductSiteLaunchDate : 2013-07-11T05:38:16.341Z Size : 1/4" (.236-.275) Style : ER-20 Spring Collet SupplierDeclaredDgHzRegulation : not_applicable UnitCount : 1 UnspscCode : 27111700