2.5 Mod Spur Gear 10T - 40T Flat Gear 45 Steel Transmission Gears OD 30-105mm

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2.5 Mod Spur Gear 10T - 40T Flat Gear 45 Steel Transmission Gears OD 30-105mm

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By HomeDIYer®

Modulus: 2.5Modul

Teeth-OD: 10T - OD 30mm

QTY(Pcs): 1

Price:

$10.65 USD

Stock:

In stock (500 units), ready to be shipped

Quantity:

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2.5 Module Spur Gear — Precision 45 Steel Flat Gear for Reliable Transmission

When your drive system demands consistent torque transfer and dimensional accuracy, undersized or poorly machined gears become the weakest link. Engineers, robotics builders, and DIY machine makers who need a dependable 2.5 module spur gear will find this range covers the most common tooth counts in a single catalog entry.

These flat spur gears are machined from 45 carbon steel and are available in tooth counts from 10T to 40T, with corresponding outer diameters ranging from 30mm to 105mm (approximately 1.18 in to 4.13 in). The module is 2.5, giving a consistent pitch that mates with any standard 2.5 Mod gear or rack.

Typical use cases include custom CNC router axis drives, open-frame 3D printer extruder gearboxes, small-batch conveyor reduction stages, and educational robotics platforms requiring a 2.5 mod spur gear with a defined OD for chassis clearance calculations.

⚙️ Compatible with any standard Module 2.5 gear, rack, or pinion. Verify bore diameter and keyway requirements before ordering.

✅ Key Features of These 2.5 Mod Spur Gears

🔩45 Carbon Steel Construction — Machined from 45 steel for solid hardness and wear resistance in continuous-duty transmission applications.
📐Wide Tooth Range: 10T – 40T — Covers OD 30mm to 105mm (1.18"–4.13") in a single product family, reducing sourcing complexity for multi-stage gearboxes.
⚙️Standard 2.5 Module Pitch — Fully interchangeable with any Module 2.5 mating gear, rack, or pinion; no custom tooling required.
🏗️Flat Gear Profile — Uniform face width across the tooth range suits parallel-shaft drive layouts in robotics frames, CNC gantries, and conveyor drives.
📦Multi-Pack Quantity Options — Available in 1–5 piece packs per variant, allowing you to order spares or matched gear pairs in a single transaction.
🔄Consistent Dimensional Accuracy — Tooth profile and OD tolerance maintained across the full 10T–40T range for predictable center-distance calculations.

📐 Technical Specifications — 2.5 Module Spur Gear

Module	2.5
Tooth Count Range	10T – 40T
Outer Diameter Range	30mm – 105mm (1.18" – 4.13")
Material	45 Carbon Steel
Gear Type	Spur Gear (Flat)
Pressure Angle	20° (standard)
Face Width	See variant options
Bore Diameter	See variant options
Keyway	See variant options
Surface Finish	See variant options
Available Quantities	1 / 2 / 3 / 4 / 5 pcs per order

❓ Frequently Asked Questions

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

Select the tooth count based on your required gear ratio and available center distance. For a 2.5 module gear pair, the center distance equals (T1 + T2) x 2.5 / 2. Use a smaller tooth count (10T–15T) as the pinion and a larger count (20T–40T) as the driven gear to achieve speed reduction.

What is the pressure angle of these spur gears?

These gears use the standard 20° pressure angle, the most widely adopted profile for industrial and hobbyist spur gears. They will mesh correctly with any other Module 2.5, 20° pressure angle gear or rack.

Are these gears suitable for outdoor or corrosive environments?

45 carbon steel has moderate corrosion resistance. For outdoor or humid environments, apply a light machine oil or grease coating, or consider a surface treatment such as black oxide or zinc plating after purchase. For highly corrosive conditions, a stainless steel gear may be more appropriate.

Will these gears mesh with a Module 2.5 rack or worm gear?

Yes, these spur gears are fully compatible with any standard Module 2.5 rack. They are not designed to mesh with worm gears, which require a matched worm wheel with a specific lead angle. For rack-and-pinion linear motion systems, any tooth count in this range will work as long as the rack is also Module 2.5.

How do I verify the bore diameter before ordering?

Bore diameter varies by tooth count and is listed in the variant details or product images. If you need a specific bore size to fit a shaft, check the variant specifications or contact us to confirm before placing your order. Custom bore machining is not included.

What load capacity can these gears handle?

Load capacity depends on tooth count, face width, operating speed, and lubrication. 45 carbon steel spur gears in this module range are suitable for light-to-medium duty applications such as robotics, small CNC machines, and educational equipment. For heavy industrial loads or high-cycle fatigue applications, consult a gear engineer to verify the design.

Can I order a matched gear pair in one transaction?

Yes. Each variant is sold independently by tooth count and quantity. Add the desired tooth count variants to your cart separately to build a matched pair or multi-stage gear set in a single order.

🛒 Select your Teeth-OD and QTY above, then add to cart.