1 Mod 20-24 Teeth Spur Gears Transmission Gear With Step Motor Pinion Gears

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1 Mod 20-24 Teeth Spur Gears Transmission Gear With Step Motor Pinion Gears

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Choose Model: 1M 20T

Bore: 5mm (Blue Nylon)

Packing Quantity: 1 pcs

Price:

$13.34 USD

Stock:

In stock (500 units), ready to be shipped

Quantity:

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1 Mod 20–24 Tooth Spur Gears — Reliable Transmission for DIY Automation & Robotics

When your CNC router, 3D printer, or stepper motor drive system demands precise, low-backlash power transmission, choosing the wrong gear can stall your entire build. Makers, hobbyists, and small workshop engineers who need a dependable 1-module spur gear in a wide range of tooth counts and bore configurations will find exactly what they need here.

These 1 Mod spur gears are available in 20T, 21T, 22T, 23T, and 24T tooth counts, machined from either Blue Nylon (PA66) or Stainless Steel (SUS304). Bore options span from 4mm to 14mm (~0.16"–0.55"), including round bores, D-flat bores, step bores (17mm and 20mm step), and keyway bores (3×1.4mm and 4×1.8mm). Tooth thickness variants of 12mm are also available for wider face-width applications.

Typical use cases include stepper motor pinion drives for desktop CNC machines, rack-and-pinion linear actuators in DIY automation rigs, and gear-reduction stages in small robotic arms or conveyor systems — all scenarios where a 1-module pitch and compact outer diameter are essential for tight spatial constraints.

⚙️ Compatible with 1 Module (1 Mod) gear systems — pairs with 1M racks, pinions, and mating spur gears of any tooth count sharing the same module.

✅ Key Features of These 1 Mod Spur Gears

🔩

Wide Tooth Count Range

Available in 20T, 21T, 22T, 23T, and 24T — choose the ratio that fits your gear train without custom machining.

🎯

Multiple Bore Configurations

Round, D-flat, step (17mm / 20mm), and keyway bores (3×1.4mm, 4×1.8mm, 5×2.3mm) for secure shaft coupling without slipping.

🛡️

Two Material Options

Blue Nylon (PA66) for lightweight, low-noise, self-lubricating applications; Stainless Steel (SUS304) for higher load, corrosion-resistant environments.

📐

Precise 1 Module Pitch

Standard 1M tooth profile ensures accurate meshing with any 1-module rack or mating gear — no profile mismatch or premature wear.

📦

Single or 5-Pack Quantities

Order 1 pcs for prototyping or 5 pcs for production builds — multi-pack pricing offers better value per unit.

🔧

Stepper Motor Pinion Ready

Bore sizes from 4mm to 14mm cover the most common NEMA 17 and NEMA 23 stepper motor shaft diameters for direct pinion mounting.

📐 Technical Specifications — 1 Mod Spur Gears

Module	1M (1 mm/tooth)
Tooth Count	20T / 21T / 22T / 23T / 24T
Pressure Angle	20°
Pitch Diameter	20mm / 21mm / 22mm / 23mm / 24mm (≈ 0.79"–0.94")
Outer Diameter (approx.)	22mm / 23mm / 24mm / 25mm / 26mm (≈ 0.87"–1.02")
Tooth Thickness (standard)	Typically 10–15mm (see variant options for 12mm face-width variants)
Bore Diameter Range	4mm – 14mm (≈ 0.16"–0.55"); see variant options
Bore Types Available	Round, D-flat, Step (17mm / 20mm), Keyway (3×1.4mm, 4×1.8mm, 5×2.3mm)
Material — Nylon	Blue PA66 Nylon (self-lubricating, low noise)
Material — Steel	Stainless Steel SUS304 (corrosion resistant)
Packing Quantity	1 pcs or 5 pcs (see variant options)
Weight	See variant options

❓ Frequently Asked Questions

How do I choose the right tooth count (20T, 21T, 22T, 23T, or 24T)?

The tooth count determines your gear ratio when paired with a mating gear or rack. For a 1:1 ratio, use matching tooth counts on both gears. For speed reduction, pair a smaller pinion (e.g., 20T) with a larger gear. For a rack-and-pinion system, the tooth count affects linear travel per motor revolution — a 20T gear with 1M pitch moves the rack 20mm × π ≈ 62.8mm per full rotation.

What is the difference between Blue Nylon and Stainless Steel versions?

Blue Nylon (PA66) gears are lightweight, self-lubricating, and run quietly — ideal for low-to-medium load applications like 3D printers, small CNC routers, and light robotics. Stainless Steel (SUS304) gears handle higher torque and loads, resist corrosion, and are suited for more demanding automation or outdoor-adjacent environments. Stainless Steel variants are priced higher due to material and machining costs.

Which bore type should I choose — round, D-flat, step, or keyway?

Round bores are the most universal and work with a set screw for light-duty applications. D-flat bores (D Bore) provide a flat face that prevents rotation under torque — recommended for stepper motor shafts with a flat. Step bores (17mm or 20mm step) allow the gear to seat against a shoulder on the shaft for axial positioning. Keyway bores (e.g., 3×1.4mm, 4×1.8mm) are used with a matching key for high-torque, slip-free coupling.

Are these gears compatible with standard 1 Module racks and other 1M gears?

Yes. All gears in this listing use a standard 1 Module (1M) tooth profile with a 20° pressure angle, which is the most common metric gear standard. They will mesh correctly with any other 1M spur gear, rack, or pinion of the same module — regardless of tooth count — as long as the face widths are compatible.

What stepper motor shaft sizes do these gears fit?

The bore range of 4mm–14mm covers the most common stepper motor output shaft diameters: NEMA 17 motors typically have 5mm shafts, NEMA 23 motors commonly use 6.35mm (1/4") or 8mm shafts, and larger NEMA 34 motors may use 10mm or 12mm shafts. Check your motor's datasheet for the exact shaft diameter and flat dimension before selecting a D-bore or keyway variant.

Can I use these gears outdoors or in humid environments?

Stainless Steel (SUS304) variants offer good corrosion resistance and are suitable for humid or mildly corrosive environments. Blue Nylon variants are moisture-resistant but may absorb small amounts of water over time, which can slightly affect dimensional tolerances. For fully outdoor or wet environments, the Stainless Steel option is recommended.

What is the advantage of ordering the 5-pack over single pieces?

The 5-pack provides a lower per-unit cost compared to buying five individual pieces separately, making it more economical for production builds, replacement stock, or multi-axis machines that require the same gear on several axes. It also reduces the number of separate orders needed for larger projects.

🛒 Select your tooth count, bore size, and packing quantity above, then add to cart.