Specification Brand : Shars BulletPoint1 : Back plate needs to be machined in order to fit the lathe chuck BulletPoint2 : Bolt Circle Diameter: 3.740", Thru Hole: 2.205" BulletPoint3 : Chuck Thickness: 2.953" BulletPoint4 : TIR (Inch): 0.005" BulletPoint5 : Plain Back Mount, Independent, 4 Jaws BulletPoint6 : Plain Back Mount, Independent, 4 Jaws CompatibleDevices : Lathe ExternallyAssignedProductIdentifier : 1252706891355 ExternallyAssignedProductIdentifier1 : 0000542174924 ExternallyAssignedProductIdentifier2 : 000542174924 Horsepower : 60 watts IncludedComponents : Lathe Chuck ItemName : SHARS 8" 4 JAW INDEPENDENT CHUCK WITH SEMI-MACHINED D1-6 BACK PLATE, MACHINING REQUIRED 202-5421+202-7492 R[ ItemPackageQuantity : 1 ItemTypeKeyword : power-metal-lathes Manufacturer : Shars Material : Cast Iron PartNumber : 202-5421+202-7492 Pattern : Plain Back ProductDescription : To achieve the .0005" radial runout and repeatability, it's required to use the 4 micro adjustment set screws to true the designated ground bar stock, not the chuck body. Do not attempt to put the indicator on the outside diameter of the chuck body to dial it to zero first as this would create more runout on the bar stock. The adjustable chuck is intended to give high repeatability clamping on a particular bar stock size after the set screw adjustment. After the adjustment is made on a particular bar stock rod, for example 1/2", it's required to true the bar stock again when clamping a different size diameter, for example 1". ProductSiteLaunchDate : 2019-05-23T07:00:00.000Z Speed : 12000 rpm Style : Independent Wattage : 60 watts