STS S8M 10T-40T Timing Belt Pulleys Pitch 8mm Teeth Width 27mm AF-type 45# Steel
STS S8M 10T-40T Timing Belt Pulleys Pitch 8mm Teeth Width 27mm AF-type 45# Steel
STS S8M 10T-40T Timing Belt Pulleys Pitch 8mm Teeth Width 27mm AF-type 45# Steel
STS S8M 10T-40T Timing Belt Pulleys Pitch 8mm Teeth Width 27mm AF-type 45# Steel
STS S8M 10T-40T Timing Belt Pulleys Pitch 8mm Teeth Width 27mm AF-type 45# Steel
STS S8M 10T-40T Timing Belt Pulleys Pitch 8mm Teeth Width 27mm AF-type 45# Steel
STS S8M 10T-40T Timing Belt Pulleys Pitch 8mm Teeth Width 27mm AF-type 45# Steel
STS S8M 10T-40T Timing Belt Pulleys Pitch 8mm Teeth Width 27mm AF-type 45# Steel
STS S8M 10T-40T Timing Belt Pulleys Pitch 8mm Teeth Width 27mm AF-type 45# Steel
STS S8M 10T-40T Timing Belt Pulleys Pitch 8mm Teeth Width 27mm AF-type 45# Steel
STS S8M 10T-40T Timing Belt Pulleys Pitch 8mm Teeth Width 27mm AF-type 45# Steel
STS S8M 10T-40T Timing Belt Pulleys Pitch 8mm Teeth Width 27mm AF-type 45# Steel
STS S8M 10T-40T Timing Belt Pulleys Pitch 8mm Teeth Width 27mm AF-type 45# Steel
STS S8M 10T-40T Timing Belt Pulleys Pitch 8mm Teeth Width 27mm AF-type 45# Steel
STS S8M 10T-40T Timing Belt Pulleys Pitch 8mm Teeth Width 27mm AF-type 45# Steel
STS S8M 10T-40T Timing Belt Pulleys Pitch 8mm Teeth Width 27mm AF-type 45# Steel
STS S8M 10T-40T Timing Belt Pulleys Pitch 8mm Teeth Width 27mm AF-type 45# Steel
STS S8M 10T-40T Timing Belt Pulleys Pitch 8mm Teeth Width 27mm AF-type 45# Steel
STS S8M 10T-40T Timing Belt Pulleys Pitch 8mm Teeth Width 27mm AF-type 45# Steel
STS S8M 10T-40T Timing Belt Pulleys Pitch 8mm Teeth Width 27mm AF-type 45# Steel
STS S8M 10T-40T Timing Belt Pulleys Pitch 8mm Teeth Width 27mm AF-type 45# Steel
STS S8M 10T-40T Timing Belt Pulleys Pitch 8mm Teeth Width 27mm AF-type 45# Steel
STS S8M 10T-40T Timing Belt Pulleys Pitch 8mm Teeth Width 27mm AF-type 45# Steel
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STS S8M 10T-40T Timing Belt Pulleys Pitch 8mm Teeth Width 27mm AF-type 45# SteelSTS S8M 10T-40T Timing Belt Pulleys Pitch 8mm Teeth Width 27mm AF-type 45# SteelSTS S8M 10T-40T Timing Belt Pulleys Pitch 8mm Teeth Width 27mm AF-type 45# SteelSTS S8M 10T-40T Timing Belt Pulleys Pitch 8mm Teeth Width 27mm AF-type 45# SteelSTS S8M 10T-40T Timing Belt Pulleys Pitch 8mm Teeth Width 27mm AF-type 45# SteelSTS S8M 10T-40T Timing Belt Pulleys Pitch 8mm Teeth Width 27mm AF-type 45# SteelSTS S8M 10T-40T Timing Belt Pulleys Pitch 8mm Teeth Width 27mm AF-type 45# SteelSTS S8M 10T-40T Timing Belt Pulleys Pitch 8mm Teeth Width 27mm AF-type 45# SteelSTS S8M 10T-40T Timing Belt Pulleys Pitch 8mm Teeth Width 27mm AF-type 45# SteelSTS S8M 10T-40T Timing Belt Pulleys Pitch 8mm Teeth Width 27mm AF-type 45# SteelSTS S8M 10T-40T Timing Belt Pulleys Pitch 8mm Teeth Width 27mm AF-type 45# SteelSTS S8M 10T-40T Timing Belt Pulleys Pitch 8mm Teeth Width 27mm AF-type 45# SteelSTS S8M 10T-40T Timing Belt Pulleys Pitch 8mm Teeth Width 27mm AF-type 45# SteelSTS S8M 10T-40T Timing Belt Pulleys Pitch 8mm Teeth Width 27mm AF-type 45# SteelSTS S8M 10T-40T Timing Belt Pulleys Pitch 8mm Teeth Width 27mm AF-type 45# SteelSTS S8M 10T-40T Timing Belt Pulleys Pitch 8mm Teeth Width 27mm AF-type 45# SteelSTS S8M 10T-40T Timing Belt Pulleys Pitch 8mm Teeth Width 27mm AF-type 45# SteelSTS S8M 10T-40T Timing Belt Pulleys Pitch 8mm Teeth Width 27mm AF-type 45# SteelSTS S8M 10T-40T Timing Belt Pulleys Pitch 8mm Teeth Width 27mm AF-type 45# SteelSTS S8M 10T-40T Timing Belt Pulleys Pitch 8mm Teeth Width 27mm AF-type 45# SteelSTS S8M 10T-40T Timing Belt Pulleys Pitch 8mm Teeth Width 27mm AF-type 45# SteelSTS S8M 10T-40T Timing Belt Pulleys Pitch 8mm Teeth Width 27mm AF-type 45# SteelSTS S8M 10T-40T Timing Belt Pulleys Pitch 8mm Teeth Width 27mm AF-type 45# Steel

STS S8M 10T-40T Timing Belt Pulleys Pitch 8mm Teeth Width 27mm AF-type 45# Steel

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Price:
$16.05 USD
Stock:
In stock (500 units), ready to be shipped

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Description

S8M Timing Belt Pulleys — 8mm Pitch, 27mm Tooth Width for Precision Drive Systems

When your CNC router, 3D printer, or automation rig demands slip-free synchronous motion, a mismatched or worn pulley becomes the weakest link in the entire drivetrain. Engineers, makers, and machine builders who need reliable torque transmission without belt creep rely on dimensionally accurate S8M pulleys machined to tight tolerances. These STS S8M timing belt pulleys are designed for that exact use case.

Each pulley is machined from 45# carbon steel and finished with a black oxide or natural steel surface. The tooth profile follows the S8M (8mm pitch) standard with a 27mm tooth width (belt contact face). Tooth counts range from 10T to 40T, and AF-type bores are available from 6mm to 28mm (approximately 0.24 in to 1.10 in), covering the most common shaft diameters used in servo and stepper motor applications.

Typical applications include CNC gantry drives requiring consistent step accuracy, robotic joint actuators where backlash must be minimized, and industrial conveyor or indexing systems using S8M synchronous belts. The AF-type bore with set-screw clamping makes shaft mounting straightforward without requiring a keyway.

⚙️ Compatible with standard S8M synchronous timing belts (8mm pitch). Verify bore diameter matches your shaft before ordering.

✅ Key Features of These S8M Timing Belt Pulleys

🔩45# Carbon Steel Construction

Machined from medium-carbon 45# steel for solid rigidity and resistance to deformation under cyclic belt tension loads.

📐8mm Pitch S8M Profile

Tooth geometry conforms to the S8M synchronous belt standard, ensuring accurate mesh and consistent pitch-line engagement across the full tooth count range.

📏27mm Tooth Width (AF-Type)

The 27mm belt contact face accommodates standard S8M belt widths. AF-type bore accepts a set screw for secure shaft clamping without a keyway.

🎯Wide Tooth Count Range: 10T–40T

Seventeen tooth count options from 10T to 40T let you dial in the exact speed ratio needed for your drive system without custom machining.

🔧Bore Range 6mm–28mm

Available bore diameters from 6mm to 28mm (including 12.7mm for inch shafts) cover stepper motor shafts, servo output shafts, and standard metric rod stock.

⚡Zero-Slip Synchronous Drive

The positive tooth engagement of the S8M profile eliminates belt slip, maintaining positional accuracy in open-loop stepper and closed-loop servo systems alike.

📐 Technical Specifications — S8M Timing Belt Pulleys

Belt Standard S8M (Synchronous, 8mm pitch)
Tooth Width 27mm (approx. 1.06 in)
Tooth Count 10T, 12T, 13T, 14T, 15T, 16T, 17T, 18T, 19T, 20T, 22T, 24T, 25T, 26T, 28T, 30T, 40T
Bore Diameter 6mm, 8mm, 10mm, 12mm, 12.7mm, 14mm, 15mm, 16mm, 17mm, 18mm, 19mm, 20mm, 22mm, 24mm, 25mm, 28mm
Bore Type AF-type (set-screw clamping, no keyway required)
Material 45# Carbon Steel
Surface Finish See variant options
Pitch Diameter See variant options
Flange See variant options
Sold As 1 piece per order (1Pcs)

❓ Frequently Asked Questions

How do I choose the right tooth count for my application?

The tooth count determines the pitch diameter and, combined with your motor pulley, sets the drive ratio. A higher tooth count gives a larger pitch diameter and lower belt tension for the same torque. Match the tooth count to your required speed ratio: divide the driven shaft speed by the drive shaft speed to get the ratio, then select tooth counts accordingly (e.g., 20T drive / 40T driven = 2:1 reduction).

What bore size should I select for my stepper or servo motor shaft?

Measure your motor shaft diameter precisely with calipers. Common stepper motor shaft diameters are 5mm, 6.35mm (1/4 in), 8mm, and 10mm. Servo motors often use 8mm, 10mm, 12mm, or larger shafts. Select the bore that matches your shaft — the AF-type set screw clamps directly onto the shaft, so a close fit is important for concentricity and torque transfer.

Is the AF-type bore strong enough for high-torque applications?

AF-type (set-screw) bores are suitable for moderate-torque synchronous drive applications typical of CNC machines, 3D printers, and light industrial automation. For very high torque or shock-load environments, a keyed bore or interference-fit hub is generally preferred. If your application involves sustained high torque, contact us to confirm suitability.

Will these pulleys work with any S8M timing belt?

Yes — these pulleys are machined to the S8M synchronous belt standard (8mm pitch). They are compatible with any S8M open-end or closed-loop timing belt of matching width (27mm or narrower). Ensure the belt width does not exceed the 27mm tooth face width of the pulley.

What is the corrosion resistance of 45# carbon steel pulleys?

45# carbon steel has moderate corrosion resistance. For indoor, dry environments typical of CNC workshops and electronics labs, the material performs well over long service life. For humid or outdoor environments, consider applying a light machine oil or corrosion-inhibiting coating. If your application requires stainless steel, contact us to confirm availability.

How do I decide between a 10T and a 40T pulley for the same shaft?

A 10T pulley has a smaller pitch diameter and is typically used on the drive (motor) side to achieve speed reduction. A 40T pulley is used on the driven side for a 4:1 reduction ratio when paired with a 10T. If you need speed increase rather than reduction, place the larger tooth count on the motor shaft. Always verify that the minimum bend radius of your S8M belt is compatible with the small-diameter 10T pulley.

Can I use a 12.7mm bore pulley on a 1/2-inch shaft?

Yes — 12.7mm is the metric equivalent of 1/2 inch (0.500 in). The 12.7mm bore option is specifically included to accommodate inch-standard shafts common in North American servo and stepper motor assemblies. Confirm your shaft is exactly 12.70mm / 0.500 in before ordering.

🛒 Select your Number of Teeth and Bore diameter above, then add to cart.

 

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