{"product_id":"s2m-42t-timing-belt-pulley-step-bore-4mm-10mm-belt-100pcs","title":"Timing Belt Pulley With Step S2M-42T-Bore 4mm For 10mm Wide Timing Belt 100pcs","description":"\u003cdiv class=\"hdiy-desc\"\u003e\n\u003cdiv class=\"hdiy-overview\"\u003e\n\u003ch2\u003eS2M 42-Tooth Stepped Timing Belt Pulley — Precision Drive for 10mm Belts\u003c\/h2\u003e\n\u003cp\u003eWhen your motion system demands consistent torque transfer and zero belt slip, a poorly fitted pulley becomes the weakest link. Engineers, makers, and automation builders working with S2M belt drives need a stepped pulley that locks belt alignment and maintains pitch accuracy across thousands of cycles. This S2M 42T stepped timing belt pulley with a 4mm bore is engineered for exactly that — delivering reliable, repeatable motion in compact drive systems.\u003c\/p\u003e\n\u003cp\u003eEach pulley features an S2M tooth profile (2mm pitch) with 42 teeth, a 4mm bore diameter, and integrated flanges (steps) on both sides to keep 10mm wide timing belts tracking true. The body is typically machined from aluminum alloy, offering a balance of low rotational inertia and structural rigidity. Outer diameter is approximately 26–27mm (≈1.02–1.06 in), with an overall hub width suited to 10mm belt width. This listing includes 100 pieces per pack.\u003c\/p\u003e\n\u003cp\u003eTypical use cases include desktop 3D printer X\/Y axis drives, small CNC router feed systems, lightweight robotic arm joints, and laboratory automation equipment where S2M belt drives are specified. The stepped flange design is especially valued in multi-axis builds where lateral belt drift would cause positioning errors.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"hdiy-compat\"\u003e\n\u003cspan class=\"hdiy-compat-icon\"\u003e⚙️\u003c\/span\u003e \u003cstrong\u003eCompatibility:\u003c\/strong\u003e Designed for S2M (2mm pitch) timing belts, 10mm wide. Bore: 4mm. Verify shaft diameter and belt width before ordering.\u003c\/div\u003e\n\u003cdiv class=\"hdiy-features\"\u003e\n\u003ch2\u003e✅ Key Features of These S2M Stepped Timing Belt Pulleys\u003c\/h2\u003e\n\u003cdiv class=\"hdiy-list\"\u003e\n\u003cdiv\u003e\n\u003cspan class=\"hdiy-icon\"\u003e🔩\u003c\/span\u003e \u003cstrong\u003eS2M 42-Tooth Profile\u003c\/strong\u003e\u003cbr\u003eMatches the 2mm pitch S2M belt standard precisely, ensuring smooth meshing and consistent torque transmission without tooth skip.\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cspan class=\"hdiy-icon\"\u003e📐\u003c\/span\u003e \u003cstrong\u003e4mm Bore with Stepped Flanges\u003c\/strong\u003e\u003cbr\u003eThe 4mm bore fits common small motor and shaft sizes. Integrated side flanges (steps) keep the 10mm belt centered and prevent lateral drift during operation.\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cspan class=\"hdiy-icon\"\u003e⚖️\u003c\/span\u003e \u003cstrong\u003eAluminum Alloy Construction\u003c\/strong\u003e\u003cbr\u003eMachined from aluminum alloy for a low-weight, high-rigidity combination — reducing rotational inertia while maintaining dimensional stability under load.\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cspan class=\"hdiy-icon\"\u003e📦\u003c\/span\u003e \u003cstrong\u003e100-Piece Pack\u003c\/strong\u003e\u003cbr\u003eSupplied in a pack of 100 units, making this ideal for production builds, batch prototyping, or stocking spare parts for multi-machine workshops.\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cspan class=\"hdiy-icon\"\u003e🎯\u003c\/span\u003e \u003cstrong\u003eConsistent Pitch Accuracy\u003c\/strong\u003e\u003cbr\u003eCNC-machined tooth geometry maintains pitch accuracy across the full 42-tooth circumference, supporting repeatable positioning in closed-loop and open-loop motion systems.\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cspan class=\"hdiy-icon\"\u003e🔄\u003c\/span\u003e \u003cstrong\u003eBroad Application Compatibility\u003c\/strong\u003e\u003cbr\u003eSuitable for 3D printers, CNC routers, robotic joints, conveyor micro-drives, and any S2M belt-driven system requiring a 4mm bore stepped pulley.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"hdiy-table-wrap\"\u003e\n\u003ch2\u003e📐 Technical Specifications — S2M Timing Belt Pulley\u003c\/h2\u003e\n\u003ctable\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eBelt Profile\u003c\/th\u003e\n\u003ctd\u003eS2M (2mm pitch)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eNumber of Teeth\u003c\/th\u003e\n\u003ctd\u003e42T\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eBore Diameter\u003c\/th\u003e\n\u003ctd\u003e4mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eCompatible Belt Width\u003c\/th\u003e\n\u003ctd\u003e10mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eOuter Diameter (approx.)\u003c\/th\u003e\n\u003ctd\u003e~26.7mm (~1.05 in)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eFlange Type\u003c\/th\u003e\n\u003ctd\u003eStepped (double flange)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eMaterial\u003c\/th\u003e\n\u003ctd\u003eAluminum alloy\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eFinish\u003c\/th\u003e\n\u003ctd\u003eSee variant options\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eHub Width\u003c\/th\u003e\n\u003ctd\u003eSee variant options\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eSet Screw\u003c\/th\u003e\n\u003ctd\u003eSee variant options\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eQuantity per Pack\u003c\/th\u003e\n\u003ctd\u003e100 pieces\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"hdiy-faq\"\u003e\n\u003ch2\u003e❓ Frequently Asked Questions\u003c\/h2\u003e\n\u003cdetails\u003e\n\u003csummary\u003eWhat does \"S2M\" mean and is it the same as \"2GT\" or \"MXL\"?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\n\u003cp\u003eS2M refers to a synchronous belt profile with a 2mm tooth pitch and a specific curvilinear tooth geometry. It is not interchangeable with 2GT (GT2) or MXL profiles — each has a different tooth shape and root radius. Always match your pulley profile to your belt profile exactly to avoid skipping or premature wear.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eWill this pulley fit a 5mm shaft if I ream the bore?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\n\u003cp\u003eThe listed bore is 4mm. Reaming to 5mm is possible on aluminum pulleys if wall thickness allows, but we recommend selecting the correct bore size from our variant options to maintain concentricity and avoid weakening the hub. Check the hub outer diameter before attempting any bore modification.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eHow do I select the right number of teeth for my drive ratio?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\n\u003cp\u003eDrive ratio is determined by the tooth count ratio between the driver and driven pulleys. For example, pairing a 20T driver with this 42T driven pulley gives a 2.1:1 reduction. Calculate your required ratio based on motor RPM and desired output speed, then select pulley tooth counts accordingly. Center distance and belt length must also be recalculated when changing tooth counts.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eAre these pulleys corrosion-resistant for humid or outdoor environments?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\n\u003cp\u003eAluminum alloy naturally forms a thin oxide layer that provides moderate corrosion resistance in typical indoor environments. For humid, wet, or outdoor applications, consider applying a light coating of dry lubricant or selecting anodized variants if available. Avoid prolonged exposure to salt spray or strong acids without additional protection.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eCan I use these in a 3D printer (e.g., CoreXY or Cartesian) with S2M belts?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\n\u003cp\u003eYes. S2M 42T pulleys are used in various motion systems where S2M belts are specified. Verify that your printer's belt path, motor shaft diameter (4mm), and belt width (10mm) match these specs. Note that many popular desktop 3D printers use 2GT (GT2) belts — confirm your belt profile before ordering.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eWhy buy a 100-piece pack — is it suitable for single-machine builds?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\n\u003cp\u003eThe 100-piece pack is designed for batch builders, small manufacturers, and workshop stock. If you are building a single machine, this pack provides ample spares for future repairs or upgrades. For single-unit needs, check if we offer smaller quantity options in our variant selector above.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eHow do I secure the pulley to the shaft — does it include a set screw?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\n\u003cp\u003eSet screw inclusion varies by variant. Check the variant options above for set screw details. If a set screw is included, use the appropriate hex key to tighten against a flat on the shaft for best holding force. If no set screw is included, the pulley may be press-fit or require a separate fastening method depending on your application.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"hdiy-cta\"\u003e🛒 Select your Bore Diameter \u0026amp; Belt Width combination above, then add to cart.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cp\u003e \u003c\/p\u003e","brand":"HomeDIYer","offers":[{"title":"S2M(BF) \/ 42T \/ 4mm \u0026 10mm","offer_id":52444079063314,"sku":"GLFBMWXDZ251016x1","price":597.04,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0884\/8936\/1682\/files\/Main-08_4650999e-bd3d-47cc-ae13-b73749b04a77.jpg?v=1783263373","url":"https:\/\/homediyer.com\/products\/s2m-42t-timing-belt-pulley-step-bore-4mm-10mm-belt-100pcs","provider":"HomeDIYer","version":"1.0","type":"link"}