{"publisher":"Xirkit — the structured parts marketplace","canonical":"https://www.xirkit.io/products/gobilda-12-mm-linear-ball-bearing-57-mm-2-pack-3112","markdown":"https://www.xirkit.io/products/gobilda-12-mm-linear-ball-bearing-57-mm-2-pack-3112/data.md","mcp":"https://www.xirkit.io/mcp","note":"Every value is traced to a cited source (see sources and per-value src). Null means unknown, never zero.","record":{"id":"311250e6-59e1-5392-b618-478a13f780c1","mpn":"1612-1221-0057","name":"goBILDA 12 mm Linear Ball Bearing 57 mm (2-pack)","manufacturer":"goBILDA","family":"bearing","summary":"goBILDA 1612-1221-0057 linear ball bearing, 2-pack: runs on 12 mm shafting, 21 mm outer diameter, 57 mm long (43 mm between the 1.2 mm retaining grooves), high-carbon steel housing and balls, plastic cage, rubber seals, 50 g each. The long version of the 30 mm bearing for stiffer, heavier linear axes; no load ratings are published.","schema_version":"3.0","revision":null,"tags":["bearing","linear ball bearing","12 mm bore bearing","12x21x57 bearing","21 mm od bearing","2rs bearing","gobilda bearing","gobilda","robotics"],"sources":[{"other":{},"id":"datasheet","url":"https://www.gobilda.com/12mm-id-linear-ball-bearing-21mm-od-57mm-length-2-pack/","title":"goBILDA 12 mm Linear Ball Bearing 57 mm (2-pack) datasheet","publisher":"goBILDA","kind":"datasheet","retrieved_at":"2026-10-01T18:15:51+00:00","field_paths":["spec.geometry.cad.bbox.height_mm","spec.geometry.cad.bbox.length_mm","spec.geometry.cad.bbox.width_mm","spec.geometry.cad.envelope_complete","spec.geometry.cad.mesh_path","spec.geometry.cad.step_path","spec.geometry.cad.verification","spec.geometry.dimensions.height_mm","spec.geometry.dimensions.length_mm","spec.geometry.dimensions.width_mm","spec.geometry.other.weight_g","spec.provides.bearing_type","spec.provides.bore_mm","spec.provides.features","spec.provides.material","spec.provides.outer_diameter_mm","spec.provides.pack_quantity","spec.provides.seal","spec.provides.width_mm","spec.usage.pinout_complete"],"notes":"sha256 8be2726fa237c95908072a903870ad9b4854aa8c9a32bf98aed933ad63fc5e7d"},{"other":{},"id":"offer0","url":"https://www.gobilda.com/12mm-id-linear-ball-bearing-21mm-od-57mm-length-2-pack/","title":"www.gobilda.com listing","publisher":null,"kind":"distributor","retrieved_at":"2026-10-01T18:17:03+00:00","field_paths":["offers"],"notes":null}],"assets":[{"other":{},"kind":"datasheet","url":"https://www.gobilda.com/12mm-id-linear-ball-bearing-21mm-od-57mm-length-2-pack/","label":"Datasheet","verification":"manufacturer","notes":null},{"other":{},"kind":"image","url":"https://cdn11.bigcommerce.com/s-x56mtydx1w/images/stencil/1734w/products/363/2651/1612-1221-0057__84150__48494.1701991656.jpg?c=1","label":"goBILDA 1612-1221-0057 12 mm linear ball bearings, 57 mm (2-pack render)","verification":"manufacturer","notes":"maker render of steel linear bearings with end seals and retaining-ring grooves"},{"other":{},"kind":"cad","url":"gobilda-1612-1221-0057.step","label":"STEP (generated from datasheet drawing)","verification":"generated","notes":"cad_check passed"}],"offers":[{"other":{"sku":"1612-1221-0057","price_breaks":[]},"supplier":"www.gobilda.com","url":"https://www.gobilda.com/12mm-id-linear-ball-bearing-21mm-od-57mm-length-2-pack/","currency":"USD","unit_price":8.99,"stock_status":"in_stock","region":"US","minimum_quantity":null,"checked_at":"2026-10-01T18:17:03+00:00","lead_time_days_min":null,"lead_time_days_max":null,"destination":"US","destination_postal_code":null,"notes":null,"price_basis":"listed","unit_price_max":null}],"best_for":[{"other":{},"label":"Linear motion and lifts","reason":"linear ball bearing for an 12 mm shaft or lead screw in a linear axis or lift.","basis":"engineering_inference"}],"children":[],"spec":{"other":{},"usage":{"other":{},"pinout":[],"derived":{},"connectors":[],"pin_mappings":[],"requirements":{"other":{},"data_inputs":[],"power_inputs":[]},"pinout_complete":false},"geometry":{"cad":{"bbox":{"width_mm":21,"height_mm":57,"length_mm":21},"features":[],"mesh_path":"gobilda-1612-1221-0057.stl","step_path":"gobilda-1612-1221-0057.step","assumptions":[],"verification":"generated","envelope_complete":true},"other":{"weight_g":50},"derived":{},"dimensions":{"other":{},"width_mm":21,"height_mm":57,"length_mm":21},"feature_boxes":[],"mounting_holes":[]},"provides":{"seal":"2RS","other":{},"bore_mm":12,"derived":{},"features":["Retaining-ring grooves 43 mm apart, 1.2 mm wide","Rubber seals, plastic cage, steel housing and balls","Maker STEP file on the product page"],"material":"High-Carbon Steel Housing and Balls, Plastic Cage, Rubber Seals","width_mm":57,"bearing_type":"linear_ball","capabilities":[],"pack_quantity":2,"outer_diameter_mm":21},"compliance":{"other":{},"derived":{},"certifications":[]},"constraints":{"other":{},"derived":{},"thermal":{"other":{}},"electrical":{"other":{}}}},"other":null,"source_type":"pdf","source_ref":"https://www.gobilda.com/12mm-id-linear-ball-bearing-21mm-od-57mm-length-2-pack/","datasheet":{"cad":{"bbox":{"max":[10.5,10.5,57],"min":[-10.5,-10.5,0],"width_mm":21,"height_mm":57,"length_mm":21},"check":{"failed":[],"passed":true},"expected":[{"d":21,"x":0,"y":0,"axis":"z","name":"outer","what":"cylinder"},{"d":12,"x":0,"y":0,"axis":"z","name":"bore","what":"hole"},{"what":"envelope_z","value":57}],"archetype":"ring_bearing","mesh_path":"/Users/sumeet/Documents/Xirkit Parent/XirkitOnboard/work/gobilda-1612-1221-0057/07_cad/part.stl","step_path":"/Users/sumeet/Documents/Xirkit Parent/XirkitOnboard/work/gobilda-1612-1221-0057/07_cad/part.step","views_png":"/Users/sumeet/Documents/Xirkit Parent/XirkitOnboard/work/gobilda-1612-1221-0057/07_cad/views.png","export_stl":"gobilda-1612-1221-0057.stl","assumptions":[],"export_step":"gobilda-1612-1221-0057.step","envelope_complete":true},"chips":[],"fields":{"bore":{"src":{"page":2,"quote":"| ID | 12mm |","method":"table","table_id":"2_1"},"unit":"mm","value":12},"seal":{"src":{"page":2,"quote":"| Material | High-Carbon Steel Housing and Balls, Plastic Cage, Rubber Seals |","method":"table","table_id":"2_1"},"unit":null,"value":"2RS"},"width":{"src":{"page":2,"quote":"| Length | 57mm |","method":"table","table_id":"2_1"},"unit":"mm","value":57},"weight":{"src":{"page":2,"quote":"| Weight | 50g Each |","method":"table","table_id":"2_1"},"unit":"g","value":50},"material":{"src":{"page":2,"quote":"| Material | High-Carbon Steel Housing and Balls, Plastic Cage, Rubber Seals |","method":"table","table_id":"2_1"},"unit":null,"value":"High-Carbon Steel Housing and Balls, Plastic Cage, Rubber Seals"},"bearing_type":{"src":{"page":2,"quote":"# 12mm ID Linear Ball Bearing (21mm OD, 57mm Length) - 2 Pack","method":"text"},"unit":null,"value":"linear_ball"},"pack_quantity":{"src":{"page":2,"quote":"# 12mm ID Linear Ball Bearing (21mm OD, 57mm Length) - 2 Pack","method":"text"},"unit":null,"value":2},"outer_diameter":{"src":{"page":2,"quote":"| OD | 21mm |","method":"table","table_id":"2_1"},"unit":"mm","value":21}},"groups":{"all":[]},"source":{"url":"https://www.gobilda.com/12mm-id-linear-ball-bearing-21mm-od-57mm-length-2-pack/","pages":2,"sha256":"8be2726fa237c95908072a903870ad9b4854aa8c9a32bf98aed933ad63fc5e7d","onboarded_at":"2026-10-01T18:17:49+00:00"},"coverage":{"pct":92,"score":"23/25","passed":true,"explained_nulls":["flange_diameter","dynamic_load","static_load","load_capacity","max_speed","operating_temperature","flange_diameter","flange_thickness"]},"entities":[],"taxonomy":{"dimensions":{"role":"mechanical_dimensions","definition":"Dimension drawing or schematic giving bore, outer diameter, width, flange"},"site_chrome":{"role":"other","definition":"Website navigation, related products and categories, footers, cookie notices"},"specifications":{"role":"electrical_ratings","definition":"Specification list or table: ID/bore, OD, width, weight, material, load ratings, seals, speed"},"pricing_ordering":{"role":"ordering_commercial","definition":"Price, SKU / part number, pack size, stock"},"product_overview":{"role":"identity_overview","definition":"Product title and description: bearing type, what shaft it fits, what it is used with, pack quantity"}},"variants":{},"commercial":{"other":{},"checked_at":"2026-10-01T18:17:03+00:00","compliance":[],"ordering_codes":[{"code":"1612-1221-0057","description":"goBILDA SKU, 2-pack"}]},"mechanical":{"dims":{"bore":{"src":{"page":2,"quote":"Ø12mm","figure":"1612-1221-0057 Schematic","method":"drawing"},"unit":"mm","value":12},"width":{"src":{"page":2,"quote":"57mm","figure":"1612-1221-0057 Schematic","method":"drawing"},"unit":"mm","value":57},"outer_diameter":{"src":{"page":2,"quote":"Ø21mm","figure":"1612-1221-0057 Schematic","method":"drawing"},"unit":"mm","value":21}},"kind":"mechanical","holes":[],"units":"mm","origin":"bearing axis on z (along the shaft), end face at z=0","features":[],"archetype":"ring_bearing","assumptions":{}},"page_index":[{"page":1,"tags":["site_chrome"],"primary":"site_chrome"},{"page":2,"tags":["product_overview","specifications"],"primary":"specifications"}],"performance":[],"schema_name":"datasheet-1","part_ratings":{}},"use_cases":["linear-motion"],"commercial":{"other":{},"checked_at":"2026-10-01T18:17:03+00:00","compliance":[],"ordering_codes":[{"code":"1612-1221-0057","description":"goBILDA SKU, 2-pack"}]},"assembly_label":"Part","assembly_level":1,"search_aliases":["12x21x57 mm linear ball bearing","1612-1221-0057","goBILDA 12 mm Linear Ball Bearing 57 mm"],"design":{"assets":[{"other":{},"kind":"datasheet","url":"https://www.gobilda.com/12mm-id-linear-ball-bearing-21mm-od-57mm-length-2-pack/","label":"Datasheet","verification":"manufacturer","notes":null,"resolved_url":"https://www.gobilda.com/12mm-id-linear-ball-bearing-21mm-od-57mm-length-2-pack/"},{"other":{},"kind":"image","url":"https://cdn11.bigcommerce.com/s-x56mtydx1w/images/stencil/1734w/products/363/2651/1612-1221-0057__84150__48494.1701991656.jpg?c=1","label":"goBILDA 1612-1221-0057 12 mm linear ball bearings, 57 mm (2-pack render)","verification":"manufacturer","notes":"maker render of steel linear bearings with end seals and retaining-ring grooves","resolved_url":"https://cdn11.bigcommerce.com/s-x56mtydx1w/images/stencil/1734w/products/363/2651/1612-1221-0057__84150__48494.1701991656.jpg?c=1"},{"other":{},"kind":"cad","url":"gobilda-1612-1221-0057.step","label":"STEP (generated from datasheet drawing)","verification":"generated","notes":"cad_check passed","resolved_url":"https://wlrumvsjnliyuuvzwnrt.supabase.co/storage/v1/object/public/geometry/gobilda-1612-1221-0057.step"}],"cad":{"verification":"generated","envelope_complete":true,"assumptions":[],"step_path":"gobilda-1612-1221-0057.step","mesh_path":"gobilda-1612-1221-0057.stl","footprint_svg_path":null,"bbox":{"length_mm":21,"width_mm":21,"height_mm":57},"features":[],"step_url":"https://wlrumvsjnliyuuvzwnrt.supabase.co/storage/v1/object/public/geometry/gobilda-1612-1221-0057.step","mesh_url":"https://wlrumvsjnliyuuvzwnrt.supabase.co/storage/v1/object/public/geometry/gobilda-1612-1221-0057.stl","footprint_svg_url":null},"limitations":["Generated geometry is an approximate mechanical envelope; inspect original manufacturer CAD when available.","Generated footprint_svg_path is an outline, not a verified electrical land pattern.","Xirkit does not run fit checks; download step_url and test fit against your own enclosure."]}}}