Check the listing for details. SHARS 8" 4 JAW INDEPENDENT LATHE CHUCK TIR CERTIFICATE + 2-1/4"-8 BACK PLATE R[. Condition: New. Listed at 219.40 USD. SHARS 8" 4 JAW INDEPENDENT LATHE CHUCK TIR CERTIFICATE + 2-1/4"-8 BACK PLATE NEW For back plate you would not need to drill any mounting holes but you will need to turn the shoulder D1 down .040" to match the back of the lathe chuck to make the chuck & back plate more concentric with the lathe spindle and reach chuck's TIR Each high quality chuck comes with a certification Product Code 202-5421+202-6204 Product Description MFG SKU # 202-5421 Brand Shars Tool Thru Hole Size 2.205 Bolt Circle Diameter 3.740 TIR (Inch) 0.0039 Number of Jaws 4 Maximum RPM 2100 Chuck Diameter 8 Mounting Plain Back Chuck Thickness 2.953 Jaw Movement Independent Maximum Capacity 7.87 Min Capacity 0.394 Product Application For use gripping odd shaped work Product Features A matching back plate would need to be machined on the face and hub OD in order to fit this chuck. For detailed information, please look for the Shars back plate machining guide. Accuracy is maintained for the entire clamping range Semi-steel chuck body made from high quality cast iron Four operating screw design with each ground and hardened to HRC 43 Both side of jaw teeth and guides are ground and hardened to HRC 58-62 Four jaws allow a square component to be perfectly centered to the chuck while achieving maximum gripping force Each set of jaws are serialized in their own set A serialized set of jaws are then finished, ground, and lapped on their designated chuck body which will be the same chuck body on the final assembly to achieve a greater accuracy Before assembling the jaw to its designated chuck body, the jaw's finish machining are performed on a closed tolerance state of the art CNC machine from Japan Operating screw's thread flank are ground on both side to achieve a tighter contact with the master jaw Each chuck has gone through rigorous accuracy and repeatability inspection with clamping and jamming multiple random testing rods or rings plain back mounting Clamping Range: Internal Jaw: Clamping Range A-A1: 0.393-3.937" Clamping Range B-B1: 2.480-7.874" What's Included Included 1 set of reversible solid hard jaws 4 M10 mounting screws 1 lathe chuck key Inspection report on runout on both inside and outside jaws Related Products SKU: 202-7491 SKU: 202-6203 7.12" D1-5 Fully Machined Lathe Chuck Back Plate for 8" Independent Chuck 6.3" Threaded Back Plate with 1-1/2 x 8 TPI for 8" 4 Jaw Independent Chuck SKU: 202-2031 SKU: 202-7490 3/8" Self-Ejecting Lathe Chuck Key 6.3" D1-4 Fully Machined Lathe Chuck Back Plate for 8" Independent Chuck Back Plate (202-6204) Description: Mounting Thread Size: T=2-1/4-8 TPI Shoulder Diameter: D1=2.953" Bolt Circle Diameter: D2=3.74" Hub Length: C=0.925'' Hub Diameter: D=3.58'' Flange Thickness: B=0.68'' Shoulder boss: h=0.185'' No. of Bolt Holes: 4 How to process back plate to guarantee Chuck's T.I.R? Fully machined back plate can be mounted onto 8" 4 jaw self Independent chuck (p/n 202-5421). As long as back plate Shoulder Diameter > chuck's D1, all 8" chuck will fit in. All back plates have 0.04" allowance, please measure the size of Chuck's D1 before process your back plates. The size of back plates's D1 should be a little bit smaller than the size of Chuck's D1. Because the gap between back plate and chuck is smaller, chuck's TIR is better. No gap is the best. D1 need to be processed before back plate can be mounted. You would not need to drill any mounting holes but you will need to turn the shoulder down .040" to match the back of the lathe chuck to make the chuck & back plate more concentric with the lathe spindle. When turning the shoulder of the backing plate, ONLY TURN THE SHOULDER OF THE BACKING PLATE WHEN ATTACHED TO THE LATHE SPINDLE. If you use a chuck to clamp the backing plate and then turn it, the backing plate will not be true to the lathe spindle and will have more runout than specified when the chuck and back plate are put together. Lathe Lathe Chuck Diameter BRAND MODEL SWING SPINDEL THREAD 3" 4" 5" 6" ATLAS 6" 1/2"-20 202-6231 ATLAS 10100 6" 1"-10 202-6107-6, 202-6107-3 ATLAS TH42 10" 1 1/2"-8 202-6230 202-6108-6, 202-6108-3 202-6192 202-9106, 202-6119 ATLAS 5991 12" 1 1/2"-8 202-6230 202-6108-6, 202-9108-3 202-6192 202-6109, 202-6119 ATLAS 3986 12" 1 1/2"-8 202-6230 202-6108-6, 202-6108-3 202-6192 202-6109, 202-6119 EMCO MAIER MAXIMAT V10 5" M39X4MM 202-6214 202-6215, 202-6217 GRIZZLY G8688 7" 3" FLANGE GRIZZLY G4000 9" M39X4MM 202-6214 202-6215, 202-6217 HARBOR FREIGHT 33684 7" 3" FLANGE HARBOR FREIGHT 45861(BV20) 9" M39X4MM 202-6214 202-6215, 202-6217 HOMIER 03911 7" 3" FLANGE JET 920N 9" 1 1/2"-8 202-6230 202-9108-6, 202-6108-3 202-6192 202-6109, 202-6119 KING CH-920 AG 9" M39X4MM 202-6214 202-6215, 202-6217 LOGAN 9" 1 1/2"-8 202-6230 202-9108-6, 202-6108-3 202-6192 202-6109, 202-6119 LOGAN 10" 1 1/2"-8 202-6230 202-9108-6, 202-6108-3 202-6192 202-6109, 202-6119 LOGAN 11" 2 1/4"-8 202-6234 202-6110, 202-6120 LOGAN 12' 2 1/4"-8 202-6234 202-6110, 202-6120 LOGAN 6510/6560 14" 2 1/4"-8 202-6234 202-6110, 202-6120 MICRO-MARK 82710 7" 3" FLANGE MICRO-MARK 82500 7" 3" FLANGE SEARS 101.07301 6" 1"-8 202-6106-6, 202-6106-3 SEARS 101.2899 12" 1 1/2"-8 202-6230 202-6106-6, 202-6106-3 202-6192 202-6109, 202-6119 SHELDON WM-46-P 13" 2 1/4"-8 202-6234 202-6110, 202-6120 SHERLINE ALL 3.5" 3/4"-16 202-6212 SIDNEY MACHINE LOT 160 14" 2 1/4"-8 202-6234 202-6110, 202-6120 SOUTH BEND CL187ZB 10" 2 1/4"-8 202-6234 202-6110 All Available to Ship NOW! at Fixed Prices SHIPPING: UPS Ground Buyer pays ACTUAL UPS shipping & insurance, and a $3.00 handling fee for this item to be shipped to all states within the continental United States. Hawaii, Alaska & and other United States Territories will ship via UPS BLUE. Canada will pay actual shipping costs plus duty fees via UPS. We can combine other auctions or store items to save on shipping. You may ask for freight cost before buying tools. Shipment will be made the same day as your payment is received and an UPS tracking number will be email to you. If your order is being shipped to an address outside of the United States, local consumer tax and/or customs duty , brokerage charges may apply and the package's recipient may need to pay these to clear customs. PAYMENT: We accept VISA, MasterCard and E-Check on PayPal.com Illinois resident adds 8% sales tax. RETURNS: If the item stated as brand new is found defective on arrival or incorrect item was shipped, buyer understands that the product will be repaired or replaced at seller's discretion, and be given a reasonable amount of time. Buyer is responsible for return shipping costs and insurance. 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