What does the keyway notation like '18/6x2.8mm' mean?

The notation means: bore diameter / keyway width x keyway depth. '18/6x2.8mm' = 18mm bore with a 6mm wide by 2.8mm deep keyway, corresponding to DIN 6885 standard for 18mm shafts.

5M 72 Zähne Riemenscheibe Zahnrad 72T Pulley für Zahnriemen 15/20/25mm Breite

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5M 72 Zähne Riemenscheibe Zahnrad 72T Pulley für Zahnriemen 15/20/25mm Breite

HomeDIYer

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By HomeDIYer®

Type: 5M-72 Zähne

Schlitzbreite: 16mm

Bohrung & Amount: 12mm & 1 Stück

Price:

$36.71 USD

Stock:

In stock (500 units), ready to be shipped

Quantity:

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5M 72-Tooth Timing Pulley — Precision Synchronous Drive for CNC, Robotics & Automation

When a slipping or mismatched pulley causes positioning errors in your CNC router, 3D printer, or automation rig, every failed run costs time and material. Engineers, makers, and small-batch manufacturers who need repeatable, zero-slip power transmission rely on a correctly specified 5M timing pulley to keep their drive systems locked in sync.

This 72-tooth synchronous pulley is machined for the 5M HTD tooth profile (5mm pitch). Available in three belt widths — 16mm (~0.63 in), 21mm (~0.83 in), and 27mm (~1.06 in) — with bore diameters ranging from 12mm to 30mm (0.47–1.18 in), including both round bores and keyed/stepped bore options (e.g., 12/4×1.8mm, 16/5×2.3mm, 18/6×2.8mm, 25/8×3.3mm keyway formats). Material is typically aluminum alloy with an anodized or natural finish for corrosion resistance and reduced rotating mass.

Typical use cases include: CNC gantry and axis drives requiring precise linear positioning; DIY robotics joint actuators and servo-driven mechanisms; conveyor and indexing systems in light industrial automation where synchronous timing belt pulley replacement or custom drive ratios are needed.

⚙️ Compatible with 5M HTD timing belts (5mm pitch). Belt widths supported: 15mm, 20mm, 25mm (select Schlitzbreite variant). Verify bore diameter and keyway dimensions against your shaft before ordering.

✅ Key Features of These 5M 72-Tooth Timing Pulleys

🔩 72-Tooth 5M HTD Profile

Engineered to the 5M HTD tooth geometry (5mm pitch, 2.06mm tooth height) for positive engagement with standard 5M timing belts — no slippage under load.

📐 Three Belt Width Options

Choose 16mm, 21mm, or 27mm groove width to match your existing belt width. Wider belts carry higher torque loads without tooth shear.

🔧 Wide Bore Range with Keyway Options

Round bores from 12mm to 25mm, plus keyed bore variants (4×1.8mm, 5×2.3mm, 6×2.8mm, 8×3.3mm, 10×3.3mm keyways) for positive shaft locking without set-screw slip.

⚖️ Aluminum Alloy Construction

Lightweight aluminum body reduces rotational inertia for faster acceleration in servo and stepper motor applications, while maintaining dimensional stability under continuous cycling.

🛡️ Anodized Surface Finish

Anodized coating resists oxidation and surface wear, extending service life in dusty workshop environments and light-duty outdoor automation enclosures.

🔄 Drop-In Replacement Compatibility

Standard 5M tooth pitch ensures direct interchangeability with other 72T 5M pulleys across common CNC kits, laser cutters, and open-source robotics platforms.

📐 Technical Specifications — 5M Timing Pulley

Tooth Profile	5M HTD (5mm pitch)
Number of Teeth	72T
Belt Width (Groove)	16mm / 21mm / 27mm (see variant options)
Bore Diameter	12–30mm round; keyed bores available (see variant options)
Keyway Dimensions	4×1.8mm / 5×2.3mm / 6×2.8mm / 8×3.3mm / 10×3.3mm (see variant options)
Material	Aluminum alloy
Surface Finish	Anodized
Pitch Diameter	Approx. 114.6mm (~4.51 in)
Outside Diameter	See variant options
Hub Thickness	See variant options
Quantity per Order	1 piece (1 Stück)
Compatible Belt	5M HTD timing belt, 15mm / 20mm / 25mm width

❓ Frequently Asked Questions

How do I choose the right belt width (Schlitzbreite)?

Match the groove width of the pulley to the width of your timing belt. If your belt is 15mm wide, select the 16mm groove variant; for a 20mm belt, choose 21mm; for a 25mm belt, choose 27mm. Using a groove slightly wider than the belt is standard practice and ensures the belt tracks correctly without binding on the flanges.

What is the difference between a round bore and a keyed bore variant?

A round bore (e.g., "12mm & 1 Stück") is a plain cylindrical hole — you secure the pulley to the shaft using a set screw. A keyed bore (e.g., "16/5×2.3mm") includes a machined keyway slot that accepts a matching key on the shaft, providing a positive mechanical lock that prevents rotational slip under high torque. For servo and stepper motor applications with frequent direction reversals, keyed bores are recommended.

What does the keyway notation like "18/6×2.8mm" mean?

The notation follows the format: bore diameter / keyway width × keyway depth. So "18/6×2.8mm" means an 18mm bore with a 6mm wide by 2.8mm deep keyway slot. This corresponds to standard DIN 6885 key dimensions for an 18mm shaft. Verify your shaft's keyway dimensions before ordering.

Is this pulley compatible with GT2 or T5 timing belts?

No. This pulley is designed exclusively for the 5M HTD tooth profile (5mm pitch, curved tooth form). It is not compatible with GT2 (2mm pitch), T5 (5mm trapezoidal pitch), or other belt profiles. The HTD tooth geometry is deeper and rounded compared to trapezoidal profiles, so mixing profiles will cause poor engagement and accelerated belt wear.

How strong is this pulley — can it handle high-torque applications?

The aluminum alloy construction provides a good strength-to-weight ratio suitable for most CNC, robotics, and light automation applications. For continuous high-torque industrial drives (e.g., conveyor systems running at full load for extended periods), verify the torque rating against your drive calculation. The 72-tooth count distributes load across more teeth simultaneously compared to smaller pulleys, which reduces per-tooth stress.

Will this pulley corrode in humid or outdoor environments?

The anodized surface finish provides good resistance to oxidation and mild corrosion in typical workshop and indoor automation environments. For prolonged outdoor exposure or contact with corrosive chemicals, consider applying a light machine oil or protective coating to the bore and hub surfaces.

How do I verify the bore size fits my motor or drive shaft?

Measure your shaft diameter with a caliper. Select the bore variant that matches your shaft diameter exactly. If your shaft diameter falls between listed bore sizes, contact us to confirm availability of custom bore options.

🛒 Select your belt width (Schlitzbreite) and bore size (Bohrung) above, then add to cart.