{"product_id":"wiseman-hss-bsw-left-hand-split-dies-british-standard-whitworth-lh-thread","title":"Wiseman HSS BSW Left Hand Split Dies – British Standard Whitworth LH Thread","description":"\u003cp data-pm-slice=\"1 3 []\" style=\"text-align: center;\"\u003e\u003cspan\u003eWiseman HSS BSW Left Hand Split Dies are manufactured from High Speed Steel (HSS) and designed for cutting new external BSW (British Standard Whitworth) left-hand threads, as well as repairing, cleaning and restoring damaged or worn existing threads.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp style=\"text-align: center;\"\u003e\u003cspan\u003eThese round split dies feature an adjustable design, allowing minor adjustments to the thread fit when used with a suitable die stock. They are particularly useful for general engineering, machinery maintenance, restoration and specialist workshop applications requiring left-hand threaded components.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp style=\"text-align: center;\"\u003e\u003cspan\u003eBSW threads feature a \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003e55° Whitworth thread profile\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e with rounded crests and roots. British Standard Whitworth is a traditional imperial thread system widely used in older British machinery, vintage vehicles, agricultural equipment and engineering assemblies.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp style=\"text-align: center;\"\u003e\u003cspan\u003eUnlike standard right-hand threads, \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003eleft-hand BSW threads tighten anticlockwise and loosen clockwise\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e. They are used in applications where the direction of rotation, mechanical movement or equipment design requires a reverse-threaded fastening.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp style=\"text-align: center;\"\u003e\u003cspan\u003eThese split dies are suitable for producing and restoring left-hand BSW threads on bolts, studs, rods, shafts and other externally threaded components.\u003c\/span\u003e\u003c\/p\u003e\n\u003ch2 style=\"text-align: center;\"\u003e\u003cspan\u003eKey Features\u003c\/span\u003e\u003c\/h2\u003e\n\u003cul data-spread=\"false\" style=\"text-align: center;\"\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eHigh Speed Steel (HSS)\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e – Durable construction for reliable thread cutting and maintenance.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eBSW Thread Form\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e – Designed for British Standard Whitworth external threads.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eLeft Hand Thread\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e – Tightens anticlockwise and loosens clockwise.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eAdjustable Split Design\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e – Allows minor adjustment of the thread fit when used with a suitable die stock.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eRound Die Construction\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e – Designed for use with compatible die stocks and die holders.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003e55° Whitworth Thread Profile\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e – Features rounded crests and roots.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eThread Cutting \u0026amp; Restoration\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e – Suitable for cutting new external threads and repairing existing threads.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eReverse Thread Applications\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e – Suitable for components requiring left-hand threaded fastenings.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eEngineering \u0026amp; Restoration Use\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e – Suitable for general machining, machinery maintenance and vintage equipment restoration.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2 style=\"text-align: center;\"\u003e\u003cspan\u003eApplications\u003c\/span\u003e\u003c\/h2\u003e\n\u003cp style=\"text-align: center;\"\u003e\u003cspan\u003eSuitable for:\u003c\/span\u003e\u003c\/p\u003e\n\u003cul data-spread=\"false\" style=\"text-align: center;\"\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003eCutting new BSW left-hand external threads on rods, bolts and studs.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003eRepairing damaged or worn BSW left-hand threads.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003eCleaning and restoring existing external threads.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003eManufacturing left-hand threaded shafts and fasteners.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003eMaintenance of older British machinery and equipment.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003eVintage and classic vehicle restoration.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003eAgricultural machinery repairs.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003eRotating assemblies requiring reverse-threaded fastenings.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003eGeneral engineering and workshop machining.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003eManufacturing replacement left-hand threaded components.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2 style=\"text-align: center;\"\u003e\u003cspan\u003eRecommended Use\u003c\/span\u003e\u003c\/h2\u003e\n\u003cp style=\"text-align: center;\"\u003e\u003cspan\u003eSelect the correct BSW left-hand split die diameter and threads per inch (TPI) to match the required external thread.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp style=\"text-align: center;\"\u003e\u003cspan\u003eSecure the die in a compatible die stock or holder, ensuring the adjustment screws are correctly positioned. Prepare the workpiece to the appropriate diameter and apply a suitable chamfer to help the die start squarely.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp style=\"text-align: center;\"\u003e\u003cspan\u003eApply a suitable cutting lubricant and rotate the die \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003eanticlockwise to cut the left-hand thread\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, viewed from the starting end of the workpiece. Periodically reverse the die clockwise slightly to help break and clear chips where appropriate for the material and cutting conditions.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp style=\"text-align: center;\"\u003e\u003cspan\u003eThe adjustable split design allows minor adjustments to the thread fit. For accurate results, check the finished thread using a suitable BSW left-hand thread gauge or correctly specified mating component.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp style=\"text-align: center;\"\u003e\u003cspan\u003eEnsure that the die is started squarely and that the correct cutting direction is maintained throughout the operation.\u003c\/span\u003e\u003c\/p\u003e\n\u003ch2 style=\"text-align: center;\"\u003e\u003cspan\u003eImportant\u003c\/span\u003e\u003c\/h2\u003e\n\u003cul data-spread=\"false\"\u003e\n\u003cli style=\"text-align: center;\"\u003e\n\u003cp\u003e\u003cspan\u003eSuitable for \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003eBSW (British Standard Whitworth) left-hand external threads only\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli style=\"text-align: center;\"\u003e\n\u003cp\u003e\u003cspan\u003eLeft-hand threads tighten anticlockwise and loosen clockwise.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli style=\"text-align: center;\"\u003e\n\u003cp\u003e\u003cspan\u003eNot suitable for cutting standard right-hand BSW threads.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli style=\"text-align: center;\"\u003e\n\u003cp\u003e\u003cspan\u003eFeatures a 55° Whitworth thread profile with rounded crests and roots.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli style=\"text-align: center;\"\u003e\n\u003cp\u003e\u003cspan\u003eNot interchangeable with BSF, UNC, UNF, metric or other thread forms.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli style=\"text-align: center;\"\u003e\n\u003cp\u003e\u003cspan\u003eAdjustable round split die for cutting and restoring external threads.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli style=\"text-align: center;\"\u003e\n\u003cp\u003e\u003cspan\u003eRequires a compatible die stock or die holder.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp style=\"text-align: center;\"\u003e\u003cspan\u003eEnsure the correct nominal diameter and TPI are selected before use.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Rennie Tool Company","offers":[{"title":"1\/4\" x 20 BSW Left Hand (13\/16\" OD)","offer_id":57740561121655,"sku":"D30301L","price":43.03,"currency_code":"GBP","in_stock":true},{"title":"5\/16\" x 18 BSW Left Hand (1\" OD)","offer_id":57740561154423,"sku":"D30402L","price":46.53,"currency_code":"GBP","in_stock":true},{"title":"3\/8\" x 16 BSW Left Hand (1\" OD)","offer_id":57740561187191,"sku":"D30452L","price":46.53,"currency_code":"GBP","in_stock":true},{"title":"1\/2\" x 12 BSW Left Hand (1.5\/16\" OD)","offer_id":57740561219959,"sku":"D30553L","price":59.66,"currency_code":"GBP","in_stock":true},{"title":"5\/8\" x 11 BSW Left Hand (1.1\/2\" OD)","offer_id":57740561252727,"sku":"D30654L","price":96.63,"currency_code":"GBP","in_stock":true},{"title":"1\" x 8 BSW Left Hand (2\" OD)","offer_id":57740561285495,"sku":"D30955L","price":128.81,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0067\/9129\/9145\/files\/WisemanSplitDie_1e3d6cb7-6db1-4e70-a26f-cc79305d4ad6.png?v=1788643504","url":"https:\/\/www.rennietool.co.uk\/products\/wiseman-hss-bsw-left-hand-split-dies-british-standard-whitworth-lh-thread","provider":"Rennie Tool Company","version":"1.0","type":"link"}