1,1.5,2 Mod Spur Gears 10T to 150T Flat C45 Steel Gears Motor Gears Rough Gears

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1,1.5,2 Mod Spur Gears 10T to 150T Flat C45 Steel Gears Motor Gears Rough Gears

HomeDIYer

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By HomeDIYer®

Gear Module: 1 Mod

Number of gear teeth: 12T

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$4.20 USD

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In stock (500 units), ready to be shipped

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C45 Steel Spur Gears — Reliable Power Transmission for Motors and DIY Drives

When your robotics project, motorized conveyor, or small-batch automation build demands a dependable gear that meshes cleanly and holds up under load, sourcing the right module and tooth count in one place saves hours of searching. These C45 steel spur gears are designed for engineers, makers, and small-batch manufacturers who need a broad selection of gear ratios without compromising on dimensional accuracy.

Each gear is machined from C45 medium-carbon steel, offering a balance of machinability and mechanical strength suitable for moderate-load drive applications. Available in three gear modules — 1 Mod, 1.5 Mod, and 2 Mod — with tooth counts spanning 10T to 150T, the outer diameter ranges from approximately 12 mm (0.47 in) for a 1 Mod 10T up to roughly 304 mm (11.97 in) for a 2 Mod 150T. Face width and bore dimensions vary by module and tooth count; see variant options for confirmed measurements.

Typical use cases include DC motor output stages in robotics and automation, gear-reduction drives for CNC axis feeds, and prototype power-transmission assemblies where a standard spur gear profile (20° pressure angle) is required. Long-tail applications such as "1 mod spur gear for stepper motor", "C45 steel gear 2 mod 30T", and "flat spur gear for DIY gearbox" are all covered within this listing.

⚙️ Compatibility: Standard metric spur gear profile — 20° pressure angle. Gears of the same module mesh with each other. Verify bore diameter and keyway requirements against your shaft before ordering.

✅ Key Features of These C45 Steel Spur Gears

🔩 C45 Medium-Carbon Steel

Machined from C45 steel for a practical combination of tensile strength and ease of secondary machining such as boring, keyway cutting, or surface treatment.

📐 Three Module Options

Available in 1 Mod, 1.5 Mod, and 2 Mod — the three most common metric spur gear modules — so you can match the gear to your existing drive components without custom tooling.

🔢 Wide Tooth-Count Range (10T – 150T)

Covers gear ratios from very small pinions up to large ring gears in a single listing, reducing the need to source from multiple suppliers for a complete gear train.

⚡ Standard 20° Pressure Angle

Conforms to the widely adopted 20° full-depth tooth profile, ensuring interchangeability with other metric spur gears of the same module from standard tooling.

🛠️ Flat / Rough-Machined Finish

Supplied in a rough-machined (unfinished bore) state, giving you the flexibility to bore, ream, or broach the hub to your exact shaft diameter and keyway specification.

📦 Broad In-Stock Selection

232 variants across three modules and tooth counts from 10T to 150T are held in stock, supporting both single-unit prototyping and small-batch production runs.

📐 Technical Specifications — C45 Steel Spur Gears

Material	C45 Medium-Carbon Steel
Gear Type	Spur Gear (straight tooth)
Pressure Angle	20°
Available Modules	1 Mod, 1.5 Mod, 2 Mod
Tooth Count Range	10T – 150T (see variant options)
Outer Diameter	See variant options
Face Width	See variant options
Bore Diameter	Rough-machined — See variant options
Hub Style	Flat / Rough (unfinished bore)
Surface Finish	Rough-machined (no coating)
Tooth Profile Standard	ISO 53 / DIN 867 metric spur gear
Quantity per Order	1 piece per unit (x1)

❓ Frequently Asked Questions

How do I choose the right module for my application?

The gear module (Mod) defines the tooth size and must match between meshing gears. 1 Mod is suited to light-load, compact drives (e.g., small robotics, hobby CNC). 1.5 Mod handles moderate loads with a slightly larger tooth. 2 Mod is appropriate for heavier-duty drives where tooth strength is a priority. Always match the module of the pinion and gear in your drive train.

Can two gears from different modules mesh together?

No. Gears of different modules are not interchangeable. A 1 Mod gear will only mesh correctly with another 1 Mod gear. Mixing modules results in incorrect tooth engagement, noise, and accelerated wear. Confirm the module of your existing gear before selecting a replacement or mating gear.

What is the bore diameter, and can I modify it?

These gears are supplied rough-machined with a pilot bore. The exact pilot bore diameter varies by module and tooth count — please contact us to confirm the specific dimension for your chosen variant. Because the bore is unfinished, you can bore, ream, or broach it to your required shaft diameter and add a keyway or set-screw flat as needed.

How strong are C45 steel gears under load?

C45 steel has a typical tensile strength of approximately 600–800 MPa in the as-machined condition. For applications requiring higher surface hardness and wear resistance, the gears can be heat-treated (quench and temper or induction hardening) after boring to your shaft size. For very high-load or high-speed applications, consider specifying a hardened or alloy-steel gear grade.

Are these gears corrosion-resistant?

C45 steel is a carbon steel and will oxidise if left unprotected in humid or wet environments. For corrosion resistance, apply a surface treatment such as black oxide, zinc plating, or a light oil coating after machining. If your application requires inherent corrosion resistance, consider stainless steel or plastic gear alternatives.

What tooth count should I choose for a specific gear ratio?

The gear ratio equals the number of teeth on the driven gear divided by the number of teeth on the driving gear (pinion). For example, a 60T gear driven by a 20T pinion gives a 3:1 reduction. Use this formula to select your tooth counts: Ratio = T_driven ÷ T_driver. This listing covers 10T to 150T, supporting a wide range of ratios in a single module.

What is the difference between a "rough gear" and a finished gear?

A rough (or blank-bore) gear has the tooth profile fully machined to specification but the bore is left as a pilot hole rather than finished to a final shaft diameter. This allows you to machine the bore to your exact shaft size, add a keyway, or apply a press fit. Finished gears come with a specific bore and keyway already machined, leaving less flexibility for customisation.

🛒 Select your Gear Module and Number of gear teeth above, then add to cart.