{"product_id":"1639-cylinder-head-extension-sets","title":"FAMAG 1639 FORSTNER BIT EXTENSION SETS","description":"\u003cp data-end=\"787\" data-start=\"336\"\u003eThe FAMAG 1639 Extension Set lets you transform standard cylinder boring bits and any tool with an 8 or 10 mm shank into deep-hole drilling powerhouses. Crafted from hardened tool steel with precision-ground run-out, each rod secures your bit via four 120°-spaced clamp screws and three machined flats for perfect concentricity. Housed in a wooden storage case, these extensions simplify long-reach tasks in cabinetry, turnery, and general woodworking.\u003c\/p\u003e\n\u003ch4 data-end=\"822\" data-start=\"789\"\u003e📏 Technical Specifications\u003c\/h4\u003e\n\u003cul data-end=\"1282\" data-start=\"823\"\u003e\n\u003cli data-end=\"896\" data-start=\"823\"\u003e\n\u003cp data-end=\"896\" data-start=\"825\"\u003e\u003cstrong data-end=\"849\" data-start=\"825\"\u003eInner Diameter (ID):\u003c\/strong\u003e 8 mm set or 10 mm set\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-end=\"966\" data-start=\"897\"\u003e\n\u003cp data-end=\"966\" data-start=\"899\"\u003e\u003cstrong data-end=\"924\" data-start=\"899\"\u003eOverall Lengths (GL):\u003c\/strong\u003e 80 mm, 125 mm, 250 mm (three-piece set)\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-end=\"1039\" data-start=\"967\"\u003e\n\u003cp data-end=\"1039\" data-start=\"969\"\u003e\u003cstrong data-end=\"992\" data-start=\"969\"\u003eUsable Length (NL):\u003c\/strong\u003e GL minus clamp-block height (~NL = GL–40 mm)\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-end=\"1106\" data-start=\"1040\"\u003e\n\u003cp data-end=\"1106\" data-start=\"1042\"\u003e\u003cstrong data-end=\"1059\" data-start=\"1042\"\u003eClamp System:\u003c\/strong\u003e Four hardened-steel screws at 120° intervals\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-end=\"1171\" data-start=\"1107\"\u003e\n\u003cp data-end=\"1171\" data-start=\"1109\"\u003e\u003cstrong data-end=\"1125\" data-start=\"1109\"\u003eShaft Flats:\u003c\/strong\u003e Three milled surfaces for zero-slip run-out\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-end=\"1230\" data-start=\"1172\"\u003e\n\u003cp data-end=\"1230\" data-start=\"1174\"\u003e\u003cstrong data-end=\"1187\" data-start=\"1174\"\u003eMaterial:\u003c\/strong\u003e Hardened, corrosion-resistant tool steel\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-end=\"1282\" data-start=\"1231\"\u003e\n\u003cp data-end=\"1282\" data-start=\"1233\"\u003e\u003cstrong data-end=\"1245\" data-start=\"1233\"\u003eStorage:\u003c\/strong\u003e Custom wooden case with foam inlay\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch4 data-end=\"1305\" data-start=\"1284\"\u003e🎯 Key Benefits\u003c\/h4\u003e\n\u003cul data-end=\"1823\" data-start=\"1306\"\u003e\n\u003cli data-end=\"1415\" data-start=\"1306\"\u003e\n\u003cp data-end=\"1415\" data-start=\"1308\"\u003e\u003cstrong data-end=\"1327\" data-start=\"1308\"\u003eExtended Reach:\u003c\/strong\u003e Drill beyond standard bit length for deep mortises, dowel holes, and lathe hollowing.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-end=\"1524\" data-start=\"1416\"\u003e\n\u003cp data-end=\"1524\" data-start=\"1418\"\u003e\u003cstrong data-end=\"1442\" data-start=\"1418\"\u003ePrecision Alignment:\u003c\/strong\u003e Clamp screws and shaft flats eliminate wobble, ensuring clean, tear-free holes.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-end=\"1636\" data-start=\"1525\"\u003e\n\u003cp data-end=\"1636\" data-start=\"1527\"\u003e\u003cstrong data-end=\"1555\" data-start=\"1527\"\u003eVersatile Compatibility:\u003c\/strong\u003e Works with all cylinder boring bits and accessories sporting an 8–13 mm shank.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-end=\"1736\" data-start=\"1637\"\u003e\n\u003cp data-end=\"1736\" data-start=\"1639\"\u003e\u003cstrong data-end=\"1664\" data-start=\"1639\"\u003eDurable Construction:\u003c\/strong\u003e Hardened tool steel resists bending and wear, even under heavy loads.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-end=\"1823\" data-start=\"1737\"\u003e\n\u003cp data-end=\"1823\" data-start=\"1739\"\u003e\u003cstrong data-end=\"1761\" data-start=\"1739\"\u003eOrganized Storage:\u003c\/strong\u003e Wooden case protects components and keeps your workshop tidy.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch4 data-end=\"1850\" data-start=\"1825\"\u003e⚙️ Application Tips\u003c\/h4\u003e\n\u003col data-end=\"2353\" data-start=\"1851\"\u003e\n\u003cli data-end=\"1944\" data-start=\"1851\"\u003e\n\u003cp data-end=\"1944\" data-start=\"1854\"\u003e\u003cstrong data-end=\"1887\" data-start=\"1854\"\u003eSelect the Correct Extension:\u003c\/strong\u003e Match ID to your bit’s shank diameter before mounting.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-end=\"2051\" data-start=\"1945\"\u003e\n\u003cp data-end=\"2051\" data-start=\"1948\"\u003e\u003cstrong data-end=\"1967\" data-start=\"1948\"\u003eSecure the Bit:\u003c\/strong\u003e Insert the bit fully, then tighten all four clamp screws in alternating sequence.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-end=\"2154\" data-start=\"2052\"\u003e\n\u003cp data-end=\"2154\" data-start=\"2055\"\u003e\u003cstrong data-end=\"2080\" data-start=\"2055\"\u003eBalance Speed \u0026amp; Feed:\u003c\/strong\u003e Reduce RPM slightly when using longer extensions to maintain stability.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-end=\"2257\" data-start=\"2155\"\u003e\n\u003cp data-end=\"2257\" data-start=\"2158\"\u003e\u003cstrong data-end=\"2184\" data-start=\"2158\"\u003eClear Chips Regularly:\u003c\/strong\u003e Periodically retract and clear swarf to prevent binding in deep holes.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-end=\"2353\" data-start=\"2258\"\u003e\n\u003cp data-end=\"2353\" data-start=\"2261\"\u003e\u003cstrong data-end=\"2284\" data-start=\"2261\"\u003eInspect \u0026amp; Maintain:\u003c\/strong\u003e Check run-out on a dial gauge and re-tighten screws before each use.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ol\u003e","brand":"Famag Tools","offers":[{"title":"8mm","offer_id":51583554322771,"sku":"F1639583","price":87.28,"currency_code":"GBP","in_stock":true},{"title":"10mm","offer_id":51583554355539,"sku":"F1639503","price":87.28,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0938\/4843\/7075\/files\/Famag-F1639583-Clinder-head-extension-3pc-set-8mm.jpg?v=1758807505","url":"https:\/\/wooddrills.co.uk\/products\/1639-cylinder-head-extension-sets","provider":"Wooddrills.co.uk","version":"1.0","type":"link"}