Your payment information is processed securely. We do not store credit card details nor have access to your credit card information.
When your motion-control build demands slip-free synchronization, a mismatched or worn pulley is the first thing that kills accuracy. Whether you are designing a CNC router, tuning a 3D printer, or assembling a compact robotics platform, the S3M timing belt pulley with 3mm pitch gives you the repeatable, zero-backlash drive you need to keep every axis on target.
Each pulley is machined from aluminum alloy with a hard-anodized or natural finish and features the BF-type flange configuration — flanged on both sides to keep your S3M belt tracking straight under load. The 11mm belt-contact width matches standard S3M belt widths directly. Tooth counts span 65 T to 150 T (pitch circle diameters approximately 62.1 mm / 2.44 in to 143.2 mm / 5.64 in), and bore options run from 8 mm to 15 mm to suit a wide range of shaft sizes.
Typical applications include CNC milling and routing machines requiring precise X/Y axis drive, desktop 3D printers using S3M belt drive systems, and lightweight robotic arms or automated conveyor stages where a compact, low-inertia pulley reduces motor load and improves dynamic response.
Flanges on both sides of the tooth profile keep the S3M belt centered and prevent lateral walk, even under side-load conditions common in CNC gantry setups.
Tooth geometry is machined to the S3M standard (3mm pitch), ensuring full mesh with S3M belts and consistent pitch-circle accuracy across all tooth counts from 65 T to 150 T.
Available in 8 mm, 10 mm, 12 mm, 14 mm, and 15 mm bores to fit stepper motor shafts, servo shafts, and custom drive shafts without additional machining in most cases.
Lightweight aluminum keeps rotational inertia low, allowing faster acceleration and deceleration cycles — a measurable advantage in high-speed 3D printing and CNC rapid-traverse moves.
The 11mm groove width is dimensioned for standard S3M-11 belts, providing full tooth engagement across the belt width for maximum torque transfer and reduced tooth wear.
Ten tooth-count options (65 T, 70 T, 72 T, 74 T, 75 T, 80 T, 90 T, 120 T, 140 T, 150 T) let you dial in the exact drive ratio your project requires without custom fabrication.
| Belt Type | S3M (Synchronous 3mm Pitch) |
|---|---|
| Pitch | 3 mm |
| Pulley Type | BF-type (Double Flange) |
| Belt Width (Groove) | 11 mm |
| Number of Teeth | 65 T / 70 T / 72 T / 74 T / 75 T / 80 T / 90 T / 120 T / 140 T / 150 T |
| Pitch Circle Diameter | See variant options (approx. 62.1 mm – 143.2 mm) |
| Bore Diameter | 8 mm / 10 mm / 12 mm / 14 mm / 15 mm |
| Material | Aluminum Alloy |
| Finish | See variant options |
| Keyway / Set Screw | See variant options |
| Overall Width | See variant options |
| Quantity per Order | 1 Piece |
The tooth count determines the pitch circle diameter and, combined with your motor-side pulley, sets the drive ratio. For a 1:1 drive use matching tooth counts on both pulleys. To reduce speed and increase torque, use a larger tooth count on the driven side. Common CNC and 3D-printer setups pair a 20 T motor pulley with a 65–80 T driven pulley for a 3.25:1 to 4:1 reduction.
NEMA 17 stepper motors typically have a 5 mm output shaft. These pulleys start at 8 mm bore, so you would need a shaft adapter or a custom-bored pulley for a direct NEMA 17 fit. For NEMA 23 motors (6.35 mm or 8 mm shaft) the 8 mm bore variant fits directly. Always measure your shaft diameter before selecting a bore.
These pulleys are designed exclusively for S3M synchronous timing belts with a 3 mm pitch and 11 mm width (S3M-11 series). Using a belt with a different pitch or width will result in poor tooth engagement and accelerated wear. Do not use GT2, HTD, or other pitch belts with these pulleys.
Aluminum alloy construction makes these pulleys well-suited for moderate-to-high speed applications such as CNC routing and 3D printing where low inertia is important. For continuous heavy-duty industrial use with sustained high torque, verify that the aluminum alloy grade and bore fit meet your load requirements, or contact us to confirm suitability.
Keyway and set-screw configuration varies by variant. Please refer to the variant detail or contact us to confirm the exact fastening method for your selected tooth count and bore combination before ordering.
Belt length (L) can be estimated with the formula: L ≈ 2C + π(D₁ + D₂)/2 + (D₂ − D₁)²/(4C), where C is the center distance between shafts and D₁, D₂ are the pitch circle diameters of the two pulleys. For S3M pulleys, pitch circle diameter = (Number of Teeth × 3 mm) / π. Round up to the nearest available S3M belt length.
Aluminum alloy offers good natural corrosion resistance for indoor and light-outdoor use. For harsh environments with exposure to salt spray, acids, or prolonged moisture, consider applying an additional protective coating or contact us to confirm the finish specification for your selected variant.
