Spur Gears 45# Steel Transmission Gear 1.5 Mod 28-35 Teeth With Step Motor Gear

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Spur Gears 45# Steel Transmission Gear 1.5 Mod 28-35 Teeth With Step Motor Gear

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Model: 1.5 Mod 28 Teeth

Bore Diameter: 6mm

Packing Quantity: 1 Pcs

Price:

$24.29 USD

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In stock (500 units), ready to be shipped

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Spur Gears 1.5 Mod 28–35 Teeth — Reliable 45# Steel Transmission for Stepper Motor Drives

When your motion system demands consistent torque transfer and dimensional accuracy, an undersized or poorly machined gear becomes the weakest link. Engineers, robotics builders, and CNC hobbyists working with stepper motor drive trains need gears that hold tight tolerances across repeated load cycles without premature wear or backlash creep.

These spur gears are machined from 45# medium-carbon steel, offering a solid balance of strength and machinability. Available in four tooth counts — 28T, 30T, 32T, and 35T — all at Module 1.5 (pitch = 1.5 mm per tooth). Bore diameters range from 6 mm (0.24 in) up to 20 mm (0.79 in), with plain bore and keyway variants (4 mm or 5 mm or 6 mm keyway depending on bore size) to suit both set-screw and keyed shaft connections.

Typical use cases include stepper motor output stages in desktop CNC routers, open-frame 3D printer extruder drives requiring a 1.5 mod gear ratio stage, and light-duty robotic arm joint drives where a compact spur gear pair replaces a belt-and-pulley system for improved positional stiffness.

⚙️ Compatibility: Module 1.5 standard — meshes with any Mod 1.5 mating gear or rack. Bore options fit shaft diameters from 6 mm to 20 mm. Keyway variants suit standard DIN 6885 keys.

✅ Key Features of These 1.5 Mod Spur Gears

🔩45# Medium-Carbon Steel Construction — Delivers a tensile strength typically in the 600–800 MPa range, resisting tooth deformation under sustained torque loads better than mild steel alternatives.
📐Module 1.5 Standardized Tooth Profile — Fully interchangeable with any Mod 1.5 gear or rack in your drivetrain; no custom tooling or adapters required.
🎯Wide Bore Range: 6 mm – 20 mm — Plain bore (6–12 mm) and keyway bore (12–20 mm with 4 mm, 5 mm, or 6 mm keys) options cover the most common stepper and servo motor shaft sizes.
⚡Four Tooth Count Options (28T / 30T / 32T / 35T) — Lets you dial in your gear ratio precisely; pair two different tooth counts to achieve the reduction or overdrive your application needs.
📦Flexible Pack Quantities (1 / 3 / 5 / 10 Pcs) — Order a single gear for prototyping or a 10-piece pack for production runs and spares inventory, with per-unit cost savings at higher quantities.
🔧Drop-In Replacement for Stepper Motor Gear Stages — Dimensionally consistent across the range, making these suitable as direct replacements in existing Mod 1.5 drive assemblies without re-engineering the housing.

📐 Technical Specifications — 1.5 Mod Spur Gears

Material	45# Medium-Carbon Steel
Module	1.5
Tooth Count	28T / 30T / 32T / 35T (see variant options)
Pressure Angle	20° (standard)
Bore Diameter	6 mm / 8 mm / 10 mm / 12 mm / 12 mm+Keyway 4mm / 14 mm+Keyway 5mm / 15 mm+Keyway 5mm / 16 mm+Keyway 5mm / 18 mm+Keyway 6mm / 20 mm+Keyway 6mm
Pitch Diameter (28T)	42 mm (1.65 in)
Pitch Diameter (30T)	45 mm (1.77 in)
Pitch Diameter (32T)	48 mm (1.89 in)
Pitch Diameter (35T)	52.5 mm (2.07 in)
Face Width	See variant options
Hub Diameter	See variant options
Surface Finish	Machined, natural steel (uncoated)
Packing Quantity	1 / 3 / 5 / 10 Pcs (see variant options)

❓ Frequently Asked Questions

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

Select tooth counts based on your required gear ratio. Divide the driven gear teeth by the driving gear teeth to get the reduction ratio. For example, pairing a 28T driving gear with a 35T driven gear gives a 1.25:1 reduction. All four options (28T, 30T, 32T, 35T) share the same Module 1.5 pitch, so they mesh freely with each other and with any other Mod 1.5 gear.

Which bore diameter should I select for my stepper motor shaft?

Match the bore to your motor shaft diameter. Common NEMA 17 stepper shafts are 5 mm (use the 6 mm bore with a 1 mm sleeve or set-screw offset) or exactly 8 mm. NEMA 23 motors typically use 6.35 mm or 8 mm shafts. For shafts 12 mm and above, choose a keyway variant to ensure positive torque transmission without relying solely on a set screw.

What is the tensile strength and load capacity of 45# steel gears?

45# medium-carbon steel (equivalent to AISI 1045) has a typical tensile strength of 600–800 MPa in the normalized condition and can be heat-treated to higher hardness if needed. For light-to-medium duty stepper motor applications — torques typically under 5 N·m per gear — these gears are well within their structural limits. For heavy industrial loads, consider specifying a heat-treated or alloy steel variant.

Are these gears corrosion-resistant for outdoor or humid environments?

45# carbon steel is not inherently corrosion-resistant. For outdoor or high-humidity environments, we recommend applying a light machine oil or grease coating during assembly and periodically re-lubricating. If long-term corrosion resistance is critical, consider pairing with a zinc-phosphate coating or selecting stainless steel gears for your application.

Will these gears mesh with my existing Mod 1.5 rack or pinion?

Yes. Module 1.5 is a standardized metric gear pitch. Any gear or rack manufactured to the Mod 1.5 standard with a 20° pressure angle will mesh correctly with these gears. Verify that your existing components are labeled as Module 1.5 (not DP or a different module) before ordering.

What is the difference between plain bore and keyway bore variants?

Plain bore variants (6–12 mm) rely on a set screw or interference fit to secure the gear to the shaft. Keyway variants include a machined slot that accepts a standard key (4 mm, 5 mm, or 6 mm depending on bore size), providing a positive mechanical lock that prevents rotational slippage under higher torque or reversing loads. For stepper motor applications with frequent direction changes, keyway bores are recommended for bores 12 mm and above.

Can I order a mixed set of tooth counts in one pack?

Each variant listing is for a single tooth count and bore combination. To get a mixed set (e.g., one 28T and one 35T gear), add each variant separately to your cart. The 3-pack, 5-pack, and 10-pack quantities are all of the same tooth count and bore as selected.

🛒 Select your Model (tooth count), Bore Diameter, and Packing Quantity above, then add to cart.