2.5 Mod 10-41 Teeth Spur Gears Transmission Gear Pinion Thickness 25mm 45# Steel

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2.5 Mod 10-41 Teeth Spur Gears Transmission Gear Pinion Thickness 25mm 45# Steel

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By HomeDIYer®

Choose Model: 2.5M 10T

Packing Quantity: 1 pcs

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$12.51 USD

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In stock (500 units), ready to be shipped

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2.5 Mod Spur Gears — Precision Transmission Pinions for Reliable DIY Drives

When a slipping or mismatched gear brings your CNC router, conveyor, or automation rig to a halt, the fix starts with the right tooth count and the right steel. These 2.5 Mod spur gears are engineered for makers, small-workshop builders, and engineering students who need a dependable transmission pinion without sourcing from an industrial distributor. Available in 10 through 41 teeth, they cover a wide reduction-ratio range in a single product family.

Each gear is machined from 45# medium-carbon steel — a material known for its balanced hardness and toughness — with a face (thickness) of 25 mm (approximately 0.98 in). The module is 2.5 mm, meaning the pitch diameter scales predictably: a 20-tooth gear has a 50 mm pitch diameter, a 30-tooth gear has a 75 mm pitch diameter, and so on. Bore diameter varies by tooth count; see variant options for exact bore dimensions.

Typical use cases include DIY CNC axis drives where a 2.5 Mod pinion meshes with a rack or larger gear, tabletop robotic arm joints requiring compact torque transmission, and educational lab setups demonstrating gear-ratio principles with a standardized module series. The 25 mm face width provides enough contact area for moderate-load continuous-duty cycles in these applications.

⚙️ Compatibility: Meshes with any 2.5 Module (Mod 2.5) spur gear, rack, or pinion. Verify bore diameter and keyway requirements against your shaft before ordering.

✅ Key Features of These 2.5 Mod Spur Gears

🔩 45# Steel Construction — Medium-carbon steel delivers a practical balance of surface hardness and core toughness, resisting tooth wear under sustained meshing loads.
📐 Wide Tooth-Count Range (10–41T) — A single product family covers ratios from roughly 1:4 down to near 1:1, reducing the need to source gears from multiple suppliers.
📏 25 mm Face Width — The 25 mm (≈0.98 in) thickness provides adequate contact area for moderate-duty continuous operation in CNC, robotics, and conveyor applications.
🎯 Standardized 2.5 Module — Module 2.5 is an ISO-standard pitch, ensuring straightforward meshing calculations and compatibility with any other Mod 2.5 gear or rack.
📦 Flexible Pack Quantities (1 / 2 / 3 pcs) — Order a single gear for a prototype or a multi-piece set for a paired drive stage — all at a per-unit price that scales with quantity.
🔄 Broad Application Fit — Suited for DIY CNC axis drives, robotic arm joints, educational gear-train demonstrations, and light industrial automation where a standardized module simplifies design.

📐 Technical Specifications — 2.5 Mod Spur Gears

Module	2.5 mm
Tooth Count Range	10T – 41T (select variant)
Face Width (Thickness)	25 mm (≈0.98 in)
Material	45# Medium-Carbon Steel
Pressure Angle	20° (standard)
Pitch Diameter	Module × Teeth (e.g., 2.5 × 20T = 50 mm)
Bore Diameter	See variant options
Keyway	See variant options
Surface Finish	Machined, natural steel
Packing Quantity	1 pcs / 2 pcs / 3 pcs (select variant)
Compatible Pitch	Mod 2.5 (ISO standard)

❓ Frequently Asked Questions

How do I calculate the pitch diameter for my chosen tooth count?

Pitch diameter = Module × Number of Teeth. For a 2.5 Mod gear: a 20T gear has a 50 mm pitch diameter, a 30T gear has 75 mm, and a 40T gear has 100 mm. Use this formula to verify center-distance spacing before ordering.

What tooth count should I choose for my gear ratio?

Divide the driven gear teeth by the driving gear teeth to get the ratio. For example, pairing a 10T pinion with a 40T gear gives a 4:1 reduction. This product covers 10T–41T, so you can achieve ratios from approximately 1:1 up to about 4:1 within this single family.

Will these gears mesh with my existing Mod 2.5 rack or gear?

Yes — any gear or rack with a 2.5 mm module and a matching 20° pressure angle will mesh correctly with these pinions. Confirm the module and pressure angle of your existing components before ordering.

How strong are these gears under continuous load?

45# steel has a tensile strength typically in the range of 600–800 MPa in its normalized state. The 25 mm face width distributes load across a reasonable contact area. These gears are suited for moderate-duty continuous operation such as CNC axis drives and robotic joints; they are not rated for heavy industrial shock loads without additional engineering analysis.

Are these gears corrosion-resistant?

45# steel is not inherently corrosion-resistant. For indoor or dry-environment use, applying a light machine oil or grease to the tooth surfaces is sufficient. For humid or outdoor environments, consider a protective coating or periodic re-lubrication to prevent surface rust.

What bore diameter and keyway does each variant have?

Bore diameter and keyway dimensions vary by tooth count. Please refer to the variant detail images or contact us to confirm the exact bore size for your selected tooth count before ordering, especially if you need a specific shaft fit.

Should I order 1, 2, or 3 pieces?

Order 1 pc for a single-stage prototype or replacement. Order 2 pcs if you need a matched pair for a parallel drive or want a spare on hand. Order 3 pcs for a multi-stage gear train or a small production run. Multi-piece packs are priced per-unit at a lower rate than single-piece orders.

🛒 Select your tooth count (Choose Model) and packing quantity above, then add to cart.