{"product_id":"3-jaw-self-centering-chuck","title":"3 Jaw Self Centering Chuck for Mini Metal Lathe","description":"\u003ch2\u003eOverview\u003c\/h2\u003e\u003cp\u003eThe Autobox 3 jaw self centering chuck is a K11-series scroll chuck sized for hobbyist and bench lathes. All three jaws advance and retract simultaneously via a single scroll plate, centering round and hex stock automatically with each tightening. Available in 3\", 4\", and 5\" body diameters to match the capacity of your lathe spindle.\u003c\/p\u003e\u003ch2\u003eAvailable Options\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e3 inch (80mm)\u003c\/strong\u003e — K11-80 — fits smaller mini lathes and rotary table work\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e4 inch (100mm)\u003c\/strong\u003e — K11-100 — the most common size for 7x10 through 7x14 mini lathes\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e5 inch (125mm)\u003c\/strong\u003e — K11-125 — for 8x16 and similar larger bench lathes\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eKey Features\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eThree-jaw scroll mechanism: single T-key tightens all three jaws simultaneously for fast, repeatable centering\u003c\/li\u003e\n\u003cli\u003eRunout tolerance ≤0.05mm (0.002\") — consistent with K11 series specification\u003c\/li\u003e\n\u003cli\u003eReversible jaws: standard internal jaws for gripping round and hex stock; reverse for clamping larger OD workpieces\u003c\/li\u003e\n\u003cli\u003eHardened steel jaws — heat-treated for wear resistance\u003c\/li\u003e\n\u003cli\u003eChuck key included — T-handle wrench ships with every unit\u003c\/li\u003e\n\u003cli\u003eThree mounting bolt holes for direct spindle nose attachment (back plate or adapter may be required — see Compatibility section)\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eSpecifications\u003c\/h2\u003e\u003ctable\u003e\n\u003ctr\u003e\n\u003cth\u003eModel\u003c\/th\u003e\n\u003cth\u003eBody Diameter\u003c\/th\u003e\n\u003cth\u003eSKU\u003c\/th\u003e\n\u003cth\u003ePrice\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eK11-80\u003c\/td\u003e\n\u003ctd\u003e3\" \/ 80mm\u003c\/td\u003e\n\u003ctd\u003eK11-80\u003c\/td\u003e\n\u003ctd\u003e$54.95\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eK11-100\u003c\/td\u003e\n\u003ctd\u003e4\" \/ 100mm\u003c\/td\u003e\n\u003ctd\u003eK11-100\u003c\/td\u003e\n\u003ctd\u003e$69.95\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eK11-125\u003c\/td\u003e\n\u003ctd\u003e5\" \/ 125mm\u003c\/td\u003e\n\u003ctd\u003eK11-125\u003c\/td\u003e\n\u003ctd\u003e$84.95\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\u003cp\u003e\u003cstrong\u003eJaw type:\u003c\/strong\u003e Reversible (internal + external use)\u003cbr\u003e\u003cstrong\u003eDrive:\u003c\/strong\u003e Single-scroll, 3-pinion bevel gear\u003cbr\u003e\u003cstrong\u003eRunout:\u003c\/strong\u003e ≤0.05mm (0.002\")\u003cbr\u003e\u003cstrong\u003eMounting:\u003c\/strong\u003e 3-bolt pattern, flat-back — spindle nose adapter or back plate required for most mini lathes\u003c\/p\u003e\u003ch2\u003eCompatibility\u003c\/h2\u003e\u003cp\u003eThis 3 jaw self centering chuck mounts to the lathe headstock spindle nose. Compatibility depends on your spindle nose type and bolt circle diameter — most mini lathes require a threaded or D1-style adapter back plate (sold separately). The 4\" (K11-100) is the most commonly used size for 7x10 through 7x14 mini lathes.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eHarbor Freight 7x10 Central Machinery (#93212) — headstock MT3 spindle, requires adapter back plate\u003c\/li\u003e\n\u003cli\u003eHarbor Freight 7x12 Central Machinery (#44142) — requires adapter back plate\u003c\/li\u003e\n\u003cli\u003eSieg C2 \/ SC2 \/ C3 mini lathe — requires adapter back plate\u003c\/li\u003e\n\u003cli\u003eGrizzly G8688 (7x12) — requires adapter back plate\u003c\/li\u003e\n\u003cli\u003eGrizzly G0765 (7x14) — requires adapter back plate\u003c\/li\u003e\n\u003cli\u003eAutobox 7x14 \/ 8x16 — designed to accept K11-100 (4\") and K11-125 (5\") with included spindle adapter\u003c\/li\u003e\n\u003cli\u003eLittleMachineShop HiTorque 7x16 — requires adapter back plate\u003c\/li\u003e\n\u003cli\u003eMicro-Mark 7x16 — requires adapter back plate\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cstrong\u003eImportant:\u003c\/strong\u003e Verify your lathe's spindle nose thread or bolt circle diameter before ordering. Message us with your machine model and we will confirm the correct adapter.\u003c\/p\u003e\u003ch2\u003eWhat's in the Box\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003e1× K11-series 3-jaw self-centering chuck (your selected size)\u003c\/li\u003e\n\u003cli\u003e1× T-handle chuck key (wrench)\u003c\/li\u003e\n\u003cli\u003e1× Set of reverse jaws\u003c\/li\u003e\n\u003cli\u003e3× Mounting bolts\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cem\u003eNote: Adapter back plate for your specific spindle nose is sold separately.\u003c\/em\u003e\u003c\/p\u003e\u003ch2\u003eFrequently Asked Questions\u003c\/h2\u003e\u003cp\u003e\u003cstrong\u003eQ: Do I need a back plate or adapter to mount this chuck?\u003c\/strong\u003e\u003cbr\u003eA: Yes, for most mini lathes. This chuck uses a flat-back 3-bolt pattern. You will need a threaded or D1-style adapter back plate to match your lathe's spindle nose. Contact us with your lathe model and we can point you to the correct adapter.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eQ: What is the difference between the 3\", 4\", and 5\" sizes?\u003c\/strong\u003e\u003cbr\u003eA: The size refers to the outer body diameter of the chuck. The 4\" (K11-100) is the most common fit for 7x10 through 7x14 mini lathes. The 3\" (K11-80) is for smaller machines or rotary table use. The 5\" (K11-125) is suited for 8x16 and larger bench lathes where the headstock can support the added diameter and mass.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eQ: Can I use this chuck to hold square or irregular stock?\u003c\/strong\u003e\u003cbr\u003eA: No — a 3-jaw self-centering chuck is designed for round and hex stock only. The three jaws move simultaneously, so they cannot independently adjust to grip irregular shapes. For irregular or off-center workpieces, see our 4-jaw independent chuck.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eQ: What is the runout accuracy of this chuck?\u003c\/strong\u003e\u003cbr\u003eA: The K11 series is rated at ≤0.05mm (0.002\") TIR. Real-world runout also depends on adapter fit, jaw condition, and workpiece surface. If you need tighter concentricity, indicate stock diameter and we can advise on jaw selection.\u003c\/p\u003e\u003ch2\u003eWhy Buy from Autobox\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eShips from our US warehouse in Toledo, OH — typical 3-5 business day delivery\u003c\/li\u003e\n\u003cli\u003eUS-based customer support — email us your lathe model and we'll confirm fit\u003c\/li\u003e\n\u003cli\u003e30-day returns, no restocking fee\u003c\/li\u003e\n\u003cli\u003eK11-series chuck: the same scroll-chuck standard used in vocational programs and small machine shops across North America\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Autobox","offers":[{"title":"3 inch","offer_id":46727460159625,"sku":"K11-80","price":54.95,"currency_code":"USD","in_stock":true},{"title":"4 inch","offer_id":46727460192393,"sku":"K11-100","price":69.95,"currency_code":"USD","in_stock":true},{"title":"5 inch","offer_id":46727460225161,"sku":"K11-125","price":84.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0762\/4923\/5593\/files\/3_4jawchuck.webp?v=1778730983","url":"https:\/\/autoboxtoolworks.com\/products\/3-jaw-self-centering-chuck","provider":"AutoBoxToolWorks","version":"1.0","type":"link"}