{"product_id":"smith-tool-311-51-217-1-1-16-acme-tension-compression-tap-holder","title":"Smith Tool 311-51-217 1-1\/16\" ACME Tension \u0026 Compression Tap Holder","description":"\u003cp\u003eThe Smith Tool 311-51-217 is a new tension and compression (floating) tap holder designed for ACME thread tapping, accepting a 1-1\/16\" square shank (SH) tap drive. The \"ACTH\" designation confirms this is an ACME-series tap holder from Smith Tool's 311-series floating tap holder line; the \"51\" sub-series identifies the body\/spindle size class, and \"217\" encodes the specific tap shank size and drive configuration. The tension and compression float mechanism allows the holder to extend and compress axially as the tap advances and retracts, compensating for minor feed-rate mismatches between the machine spindle and the tap, which is critical for ACME thread forms that require precise lead control and generates high axial loads. The tool body features a knurled lock ring for float adjustment, a hardened and black-oxide finished steel construction, and a quick-change collet-style front end with bayonet-lock pins visible at the nose for fast tap changes. Manufactured in the USA, this holder is used in CNC machining centers, turret lathes, and NC drill\/tap machines where ACME lead screws, nuts, or jack-screw components are produced at scale. Product Specifications Brand Smith Tool MPN 311-51-217 Series ACTH (ACME Tap Holder) Tap Shank Size 1-1\/16 in Square Thread Form ACME Drive Type Square Shank (SH) Holder Type Tension \u0026amp; Compression (Floating) Country of Origin USA Finish Black Oxide Body Material Hardened Steel\u003c\/p\u003e\u003ctable style=\"width:100%;border-collapse:collapse;margin-top:16px;\"\u003e\n\u003ctr style=\"background:#56555b;\"\u003e\u003cth style=\"text-align:left;padding:8px 12px;color:#fff;font-size:13px;\" colspan=\"2\"\u003eProduct Specifications\u003c\/th\u003e\u003c\/tr\u003e\n\u003ctr style=\"background:#f5f5f5;\"\u003e\n\u003ctd style=\"padding:6px 12px;font-size:13px;font-weight:600;color:#333;border-bottom:1px solid #eee;width:40%;\"\u003eBrand\u003c\/td\u003e\n\u003ctd style=\"padding:6px 12px;font-size:13px;color:#555;border-bottom:1px solid #eee;\"\u003eSmith Tool\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#ffffff;\"\u003e\n\u003ctd style=\"padding:6px 12px;font-size:13px;font-weight:600;color:#333;border-bottom:1px solid #eee;width:40%;\"\u003eMPN\u003c\/td\u003e\n\u003ctd style=\"padding:6px 12px;font-size:13px;color:#555;border-bottom:1px solid #eee;\"\u003e311-51-217\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#f5f5f5;\"\u003e\n\u003ctd style=\"padding:6px 12px;font-size:13px;font-weight:600;color:#333;border-bottom:1px solid #eee;width:40%;\"\u003eSeries\u003c\/td\u003e\n\u003ctd style=\"padding:6px 12px;font-size:13px;color:#555;border-bottom:1px solid #eee;\"\u003eACTH (ACME Tap Holder)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#ffffff;\"\u003e\n\u003ctd style=\"padding:6px 12px;font-size:13px;font-weight:600;color:#333;border-bottom:1px solid #eee;width:40%;\"\u003eTap Shank Size\u003c\/td\u003e\n\u003ctd style=\"padding:6px 12px;font-size:13px;color:#555;border-bottom:1px solid #eee;\"\u003e1-1\/16 in Square\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#f5f5f5;\"\u003e\n\u003ctd style=\"padding:6px 12px;font-size:13px;font-weight:600;color:#333;border-bottom:1px solid #eee;width:40%;\"\u003eThread Form\u003c\/td\u003e\n\u003ctd style=\"padding:6px 12px;font-size:13px;color:#555;border-bottom:1px solid #eee;\"\u003eACME\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#ffffff;\"\u003e\n\u003ctd style=\"padding:6px 12px;font-size:13px;font-weight:600;color:#333;border-bottom:1px solid #eee;width:40%;\"\u003eDrive Type\u003c\/td\u003e\n\u003ctd style=\"padding:6px 12px;font-size:13px;color:#555;border-bottom:1px solid #eee;\"\u003eSquare Shank (SH)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#f5f5f5;\"\u003e\n\u003ctd style=\"padding:6px 12px;font-size:13px;font-weight:600;color:#333;border-bottom:1px solid #eee;width:40%;\"\u003eHolder Type\u003c\/td\u003e\n\u003ctd style=\"padding:6px 12px;font-size:13px;color:#555;border-bottom:1px solid #eee;\"\u003eTension \u0026amp; Compression (Floating)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#ffffff;\"\u003e\n\u003ctd style=\"padding:6px 12px;font-size:13px;font-weight:600;color:#333;border-bottom:1px solid #eee;width:40%;\"\u003eCountry of Origin\u003c\/td\u003e\n\u003ctd style=\"padding:6px 12px;font-size:13px;color:#555;border-bottom:1px solid #eee;\"\u003eUSA\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#f5f5f5;\"\u003e\n\u003ctd style=\"padding:6px 12px;font-size:13px;font-weight:600;color:#333;border-bottom:1px solid #eee;width:40%;\"\u003eFinish\u003c\/td\u003e\n\u003ctd style=\"padding:6px 12px;font-size:13px;color:#555;border-bottom:1px solid #eee;\"\u003eBlack Oxide\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#ffffff;\"\u003e\n\u003ctd style=\"padding:6px 12px;font-size:13px;font-weight:600;color:#333;border-bottom:1px solid #eee;width:40%;\"\u003eBody Material\u003c\/td\u003e\n\u003ctd style=\"padding:6px 12px;font-size:13px;color:#555;border-bottom:1px solid #eee;\"\u003eHardened Steel\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e","brand":"DDT and More","offers":[{"title":"Default Title","offer_id":49432331419863,"sku":"8096tWS2","price":28.5,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0736\/0626\/7095\/files\/smith-tool-311-51-217-tension-compression-tap-holder-1.jpg?v=1783956524","url":"https:\/\/dansdiscounttools.com\/products\/smith-tool-311-51-217-1-1-16-acme-tension-compression-tap-holder","provider":"Dan's Discount Tools","version":"1.0","type":"link"}