Mod 2.5 Spur Gear Steel Hardened with Hub 15-40 Tooth Motor Pinion 12-40mm Bore

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Mod 2.5 Spur Gear Steel Hardened with Hub 15-40 Tooth Motor Pinion 12-40mm Bore

Name: Mod 2.5 Spur Gear Steel Hardened with Hub 15-40 Tooth Motor Pinion 12-40mm Bore
Brand: HomeDIYer
Price: 22.56 USD
Availability: InStock

HomeDIYer

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By HomeDIYer®

Models: Module 2.5【15 Tooth】

Bore Size: Pilot Hole, Roughing

Amount: 1 pcs

Price:

$22.56 USD

Stock:

In stock (500 units), ready to be shipped

Quantity:

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Module 2.5 Hardened Steel Spur Gear with Hub — Precision Motor Pinion for Demanding Drive Systems

When a stripped or undersized gear brings your build to a halt, the fix needs to be exact. Engineers, robotics builders, and CNC hobbyists who rely on consistent torque transmission need a spur gear that holds its geometry under load — not one that wears out after a few hundred cycles. This Module 2.5 spur gear with integral hub is machined for builders who cannot afford slop in their drivetrain.

Each gear is turned from medium-carbon steel and surface-hardened for wear resistance. The tooth profile follows the standard Module 2.5 (2.5 mm per tooth) involute geometry. Tooth counts span 15 to 40 teeth, giving an outer diameter range of approximately 42.5 mm to 105 mm (1.67 in to 4.13 in). The integrated hub accepts keyed bores from 12 mm up to 40 mm (0.47 in to 1.57 in) with matching keyway slots, or is available as a pilot-hole blank for custom boring.

Typical applications include motor pinion drives in 3D printer extruder gearboxes, stepper-driven CNC axis reducers, robotic arm joint actuators, and small-batch conveyor drive stages where a reliable module 2.5 steel spur gear with keyway bore is required for repeatable positioning.

⚙️ Compatibility: Meshes with any standard Module 2.5 (Mod 2.5) spur or helical gear of matching module. Verify center distance = (T₁ + T₂) × 1.25 mm before assembly.

✅ Key Features of These Module 2.5 Hardened Steel Spur Gears

🔩 Hardened Steel Construction
Medium-carbon steel with surface hardening delivers extended tooth life under continuous load, resisting pitting and surface fatigue in motor pinion applications.

📐 Standard Module 2.5 Involute Profile
Full-depth involute tooth form machined to Module 2.5 standard ensures smooth mesh and interchangeability with any Mod 2.5 mating gear in your drivetrain.

🎯 Integral Hub with Keyed Bore
The extended hub provides a secure shaft seat. Keyed bore options (12–40 mm + matching keyway) eliminate rotational slip under reversing or shock loads.

📏 Wide Tooth Count Range (15–40 T)
Ten tooth-count options from 15 T to 32 T (listed variants) let you dial in the exact gear ratio needed without custom machining a new blank.

🔧 Pilot Hole Option for Custom Boring
Select the Pilot Hole / Roughing variant to receive the gear with a small center hole, ready for in-house boring or reaming to a non-standard shaft diameter.

⚖️ Consistent Dimensional Accuracy
Tooth pitch, hub diameter, and face width are held to close tolerances across the range, supporting repeatable assembly in multi-gear reduction stages.

📐 Technical Specifications — Module 2.5 Spur Gear

Module	2.5
Tooth Count Range	15 T – 32 T (see variant options)
Pressure Angle	20°
Material	Medium-carbon steel, surface hardened
Bore Type	Keyed bore or Pilot Hole (see variant options)
Bore Diameter Range	12 mm – 40 mm (0.47 in – 1.57 in)
Keyway Width	4 mm – 12 mm (matched to bore; see variant options)
Outer Diameter (approx.)	(Tooth Count + 2) × 2.5 mm
Face Width	See variant options
Hub Style	Integral hub
Finish	See variant options
Quantity per Order	1 pc (multi-pack options available)

❓ Frequently Asked Questions

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

The gear ratio equals the driven tooth count divided by the driving tooth count. For example, pairing a 15 T motor pinion with a 30 T output gear gives a 2:1 reduction. Calculate the center distance as (T₁ + T₂) × 1.25 mm to confirm it fits your housing before ordering.

What bore size should I select for my motor shaft?

Match the bore diameter to your shaft diameter. If your shaft is 16 mm, select the "16mm + 5mm Keyway" option. If your shaft is non-standard or you plan to bore it yourself, choose "Pilot Hole, Roughing" and machine the bore to your exact dimension.

Are these gears strong enough for continuous-duty motor drives?

The surface-hardened medium-carbon steel construction is suited for continuous-duty motor pinion applications at moderate speeds and loads typical of robotics, CNC, and light industrial drives. For very high-speed or heavy shock-load environments, verify the allowable tangential load against your application's torque requirements.

Will this gear mesh with my existing Module 2.5 gears?

Yes — any two gears of the same module and pressure angle (20°) will mesh correctly. Confirm the center distance formula: C = (T₁ + T₂) × 1.25 mm. The tooth profile is standard involute, compatible with other Mod 2.5 spur gears regardless of brand.

How corrosion-resistant are these gears?

The base material is carbon steel, which is not inherently stainless. For environments with moisture or mild chemicals, apply a light machine oil or grease to the tooth faces and bore. For highly corrosive environments, consider a stainless or coated alternative.

What is the difference between the keyed bore variants and the Pilot Hole option?

Keyed bore variants arrive finish-bored to the stated diameter with a milled keyway slot, ready to mount on a matching keyed shaft. The Pilot Hole / Roughing variant has only a small center hole; you bore and key it yourself to any diameter within the hub's wall thickness, giving full flexibility for non-standard shafts.

Can I order multiple gears to build a multi-stage reduction?

Yes. Select the tooth counts for each stage separately and add each to your cart. All gears in this listing share the same Module 2.5 standard, so any two will mesh correctly when the center distance is set properly.

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