{"openapi":"3.1.0","info":{"title":"Bolt Torque API","version":"1.0.0","description":"Bolt and fastener torque maths as an API, using the standard short-form relation T = K · D · F — torque equals the nut factor times the bolt diameter times the clamp load (preload). The torque endpoint computes the tightening torque, in newton-metres, foot-pounds, inch-pounds and kilogram-force metres, from the bolt diameter, the target clamp load and a nut factor — given directly or chosen from a condition preset (dry, lubricated, zinc-plated, galvanized, waxed and more). The preload endpoint solves the inverse: the clamp load a given torque produces on a bolt of a given diameter and friction. The convert endpoint converts a torque value between newton-metres, foot-pounds, inch-pounds and kilogram-force metres. Everything is computed locally and deterministically, so it is instant and private. The K·D·F short form is an estimate that depends heavily on friction — it is engineering guidance only, so always follow the manufacturer's torque specification. Ideal for mechanical, automotive and aerospace tools, maker and assembly apps, maintenance and field-service software, and engineering calculators. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. This is fastener torque; for wire gauge and resistance use a wire-gauge API and for Ohm's law use an electronics API.","contact":{"name":"PremiumApi","url":"https://www.oanor.com/by/premiumapi"}},"servers":[{"url":"https://api.oanor.com/torque-api","description":"oanor gateway"}],"tags":[{"name":"Torque"},{"name":"Meta"}],"components":{"securitySchemes":{"oanorKey":{"type":"apiKey","in":"header","name":"x-oanor-key","description":"Get your key at https://www.oanor.com/developer/keys"}}},"security":[{"oanorKey":[]}],"paths":{"/v1/convert":{"get":{"operationId":"get_v1_convert","tags":["Torque"],"summary":"Convert torque units","description":"","parameters":[{"name":"value","in":"query","required":true,"description":"Torque value","schema":{"type":"string"},"example":"100"},{"name":"from","in":"query","required":true,"description":"nm|ftlb|inlb|kgfm","schema":{"type":"string"},"example":"nm"}],"security":[{"oanorKey":[]}],"responses":{"200":{"description":"OK","content":{"application/json":{"example":{"data":{"note":"Torque unit conversion relative to newton-metres.","input":{"from":"nm","value":100},"torque":{"nm":100,"ft_lb":73.7562,"in_lb":885.075,"kgf_m":10.19716}},"meta":{"timestamp":"2026-06-04T01:59:19.699Z","request_id":"bffe2b12-4af6-47cf-b877-da0ca343307c"},"status":"ok","message":"Torque unit conversion","success":true}}}},"401":{"description":"Missing or invalid x-oanor-key header"},"402":{"description":"Active subscription required"},"429":{"description":"Rate-limit or monthly quota reached"},"502":{"description":"Upstream did not respond"}}}},"/v1/preload":{"get":{"operationId":"get_v1_preload","tags":["Torque"],"summary":"Clamp load from torque","description":"","parameters":[{"name":"torque","in":"query","required":true,"description":"Tightening torque","schema":{"type":"string"},"example":"60"},{"name":"torque_unit","in":"query","required":false,"description":"nm|ftlb|inlb|kgfm","schema":{"type":"string"},"example":"nm"},{"name":"diameter","in":"query","required":true,"description":"Bolt diameter","schema":{"type":"string"},"example":"12"},{"name":"diameter_unit","in":"query","required":false,"description":"mm|in","schema":{"type":"string"},"example":"mm"},{"name":"condition","in":"query","required":false,"description":"Friction condition","schema":{"type":"string"},"example":"dry"},{"name":"k","in":"query","required":false,"description":"Or nut factor","schema":{"type":"string"}}],"security":[{"oanorKey":[]}],"responses":{"200":{"description":"OK","content":{"application/json":{"example":{"data":{"note":"Clamp load F = T / (K · D). Higher friction (larger K) gives less preload for the same torque.","input":{"torque_nm":60,"diameter_m":0.012,"nut_factor":0.2},"clamp_load_n":25000,"clamp_load_kn":25,"clamp_load_kgf":2549.29,"clamp_load_lbf":5620.22},"meta":{"timestamp":"2026-06-04T01:59:19.790Z","request_id":"73c4a12e-d74e-4421-90e1-264e5d8035e4"},"status":"ok","message":"Clamp load from torque","success":true}}}},"401":{"description":"Missing or invalid x-oanor-key header"},"402":{"description":"Active subscription required"},"429":{"description":"Rate-limit or monthly quota reached"},"502":{"description":"Upstream did not respond"}}}},"/v1/torque":{"get":{"operationId":"get_v1_torque","tags":["Torque"],"summary":"Tightening torque from clamp load","description":"","parameters":[{"name":"diameter","in":"query","required":true,"description":"Bolt diameter","schema":{"type":"string"},"example":"12"},{"name":"diameter_unit","in":"query","required":false,"description":"mm|in (default mm)","schema":{"type":"string"},"example":"mm"},{"name":"preload","in":"query","required":true,"description":"Clamp load","schema":{"type":"string"},"example":"25000"},{"name":"preload_unit","in":"query","required":false,"description":"n|kn|lbf|kgf","schema":{"type":"string"},"example":"n"},{"name":"condition","in":"query","required":false,"description":"dry|lubricated|zinc|galvanized|waxed","schema":{"type":"string"},"example":"dry"},{"name":"k","in":"query","required":false,"description":"Or explicit nut factor","schema":{"type":"string"}}],"security":[{"oanorKey":[]}],"responses":{"200":{"description":"OK","content":{"application/json":{"example":{"data":{"note":"T = K · D · F (nut factor × bolt diameter × clamp load). Default K = 0.2 (dry steel). Guidance only — use the maker's spec.","input":{"preload_n":25000,"diameter_m":0.012,"nut_factor":0.2},"torque":{"nm":60,"ft_lb":44.2537,"in_lb":531.045,"kgf_m":6.1183}},"meta":{"timestamp":"2026-06-04T01:59:19.890Z","request_id":"0f10fb05-9352-4ebe-a54c-55aca48ffdcd"},"status":"ok","message":"Tightening torque","success":true}}}},"401":{"description":"Missing or invalid x-oanor-key header"},"402":{"description":"Active subscription required"},"429":{"description":"Rate-limit or monthly quota reached"},"502":{"description":"Upstream did not respond"}}}},"/v1/meta":{"get":{"operationId":"get_v1_meta","tags":["Meta"],"summary":"Spec","description":"","parameters":[],"security":[{"oanorKey":[]}],"responses":{"200":{"description":"OK","content":{"application/json":{"example":{"data":{"note":"T = K·D·F short form. Nut factor presets are typical values; engineering guidance only — follow the manufacturer's torque spec.","service":"torque","endpoints":{"/v1/torque":"Tightening torque (Nm/ft-lb/in-lb/kgf-m) from bolt diameter, clamp load and nut factor.","/v1/convert":"Convert torque between Nm, ft-lb, in-lb and kgf-m.","/v1/preload":"Clamp load (preload) from a tightening torque and bolt diameter."},"conditions":["dry","plain","asreceived","steel","zinc","zincplated","galvanized","lightlyrusted","lubricated","oiled","moly","waxed","ptfe","antisize"],"description":"Bolt/fastener torque maths: torque from clamp load (T = K·D·F), the inverse clamp load, and torque unit conversion."},"meta":{"timestamp":"2026-06-04T01:59:19.984Z","request_id":"f92f4d81-36b7-419e-9568-0058faf63185"},"status":"ok","message":"Meta","success":true}}}},"401":{"description":"Missing or invalid x-oanor-key header"},"402":{"description":"Active subscription required"},"429":{"description":"Rate-limit or monthly quota reached"},"502":{"description":"Upstream did not respond"}}}}},"x-oanor-pricing":[{"slug":"free","name":"Free","price_cents_month":0,"monthly_call_quota":10835,"rps_limit":2,"hard_limit":true},{"slug":"starter","name":"Starter","price_cents_month":1235,"monthly_call_quota":20450,"rps_limit":8,"hard_limit":true},{"slug":"pro","name":"Pro","price_cents_month":3225,"monthly_call_quota":254500,"rps_limit":20,"hard_limit":true},{"slug":"mega","name":"Mega","price_cents_month":7025,"monthly_call_quota":1315000,"rps_limit":50,"hard_limit":true}],"x-oanor-marketplace-url":"https://www.oanor.com/api/torque-api"}