1 Mod 70-80 Teeth Spur Gear Transmission Gear With Step 45# Steel Motor Gears

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1 Mod 70-80 Teeth Spur Gear Transmission Gear With Step 45# Steel Motor Gears

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Choose Model: 1M 70T

Bore: 8mm

Packing Quantity: 1 pcs

Price:

$49.75 USD

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In stock (500 units), ready to be shipped

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1 Mod 70–80 Teeth Spur Gear with Step — Reliable 45# Steel Transmission Gear for DIY Automation

When your CNC router, conveyor, or robotic arm demands a gear that won't slip, strip, or flex under load, a poorly machined spur gear becomes the weakest link in your entire drivetrain. Makers, workshop engineers, and automation hobbyists who need consistent torque transfer and precise tooth engagement rely on a gear that is machined to spec — not cast to approximate. This 1 Mod 70–80 teeth spur gear with step bore is built for that exact demand.

Each gear is machined from 45# medium-carbon steel, offering a solid balance of tensile strength and machinability. The module is 1 (1M), with tooth counts of 70T, 72T, or 80T depending on the model selected. Bore diameters range from 8 mm (~0.31 in) to 25 mm (~0.98 in), with standard round bores and keyed step-bore options available. The 80T variants include a precision-machined step bore for shaft shoulder registration, with step depths of 40 mm or 50 mm depending on bore size.

Typical use cases include small-format CNC machine Z-axis drives, stepper motor output stages in 3D printer extruder gearboxes, and low-speed high-torque conveyor indexing systems where a 1 mod spur gear with keyed bore ensures zero rotational slip. The step-bore 80T variants are particularly suited to motor shaft assemblies requiring axial positioning against a shoulder.

⚙️ Compatibility: Designed for 1 Module (1M) gear systems. Mates with any 1M rack, pinion, or mating spur gear. Bore options cover 8 mm to 25 mm shafts; keyed bores require matching keyway on shaft. Verify tooth count and bore before ordering.

✅ Key Features of These 1 Mod Spur Gears with Step Bore

🔩45# Steel Construction — Medium-carbon steel provides solid tensile strength and wear resistance for sustained gear mesh under moderate-to-high loads.
📐Module 1 (1M) Standard — Fully interchangeable with any 1M rack, pinion, or mating gear in your drivetrain; tooth profile conforms to standard involute geometry.
🎯Multiple Tooth Counts — Available in 70T, 72T, and 80T configurations to match your required gear ratio and pitch circle diameter.
🔧Wide Bore Range — Round bores from 8 mm to 25 mm; keyed step bores (80T) with keyway dimensions matched to bore size for positive shaft engagement.
📏Step Bore Design (80T) — Precision-machined step allows axial shaft shoulder registration, eliminating the need for additional spacers in motor-to-gear assemblies.
📦Flexible Pack Quantities — Order as 1, 2, or 3 pieces per pack to match your project build quantity and reduce per-unit cost on multi-axis machines.

📐 Technical Specifications — 1 Mod Spur Gear

Module	1 (1M)
Tooth Count	70T / 72T / 80T (see variant options)
Material	45# Medium-Carbon Steel
Bore Type	Round bore (70T, 72T); Step bore (80T)
Bore Diameter	8 mm – 25 mm (see variant options)
Keyway	Available on select keyed bore variants (see variant options)
Step Depth (80T)	40 mm or 50 mm depending on bore size
Tooth Profile	Standard involute
Pressure Angle	20°
Surface Finish	See variant options
Weight	See variant options
Packing Quantity	1 pcs / 2 pcs / 3 pcs

❓ Frequently Asked Questions

How do I choose between 70T, 72T, and 80T?

The tooth count determines the pitch circle diameter and the gear ratio when paired with a pinion. A 70T gear paired with a 10T pinion gives a 7:1 reduction; a 72T gives a cleaner ratio with 12T or 18T pinions (6:1 or 4:1). The 80T is the largest option and is only available with a step bore. Choose based on your required output speed, torque, and the mating gear already in your system.

What is a step bore and when do I need it?

A step bore has a machined shoulder inside the bore that allows the gear to register against a shaft shoulder or motor face, fixing its axial position without a separate spacer or collar. The 80T variants use this design. If your motor shaft has a shoulder or you need the gear to sit at a precise axial location, the step bore variant is the correct choice. Standard round bore variants (70T, 72T) require a set screw, key, or external collar for axial retention.

What do the keyway dimensions mean (e.g., 12mm(4x1.8mm))?

The format is bore diameter followed by keyway width × keyway depth in millimeters. For example, "12mm(4x1.8mm)" means the bore is 12 mm in diameter with a 4 mm wide × 1.8 mm deep keyway cut into it. Your shaft must have a matching keyway and key to use these variants. If your shaft is plain (no keyway), select the plain round bore option for the same diameter.

Is 45# steel strong enough for my application?

45# steel (equivalent to AISI 1045) has a tensile strength of approximately 600–700 MPa in the normalized condition. It is well-suited for moderate-load power transmission in CNC machines, conveyor drives, and robotic joints operating at low-to-medium speeds. For very high-speed or shock-load applications, consider whether a hardened or alloy steel gear would be more appropriate for your specific torque and duty cycle.

Will this gear corrode if used in a damp workshop environment?

45# steel is not stainless and will oxidize if exposed to moisture without protection. For workshop use, applying a light machine oil or grease to the gear teeth and bore during installation provides adequate corrosion protection under normal indoor conditions. If the gear will be exposed to water, coolant mist, or outdoor environments, consider periodic re-lubrication or a protective coating.

How do I confirm this gear is compatible with my existing rack or pinion?

Compatibility requires matching the module (1M), pressure angle (20°), and tooth profile (involute). If your existing rack or pinion is marked as "M1" or "Module 1" with a 20° pressure angle, this gear will mesh correctly. Verify by checking the manufacturer's datasheet for your existing components. Mixing modules (e.g., pairing a 1M gear with a 1.25M rack) will result in incorrect mesh and rapid wear.

Can I order multiple pieces for a multi-axis machine build?

Yes. Each listing offers 1 pcs, 2 pcs, and 3 pcs packing quantity options. Select the quantity that matches your build requirement. Ordering a multi-piece pack is more economical per unit than ordering individual pieces separately, and all pieces in a pack are from the same production batch for consistent dimensions.

🛒 Select your model, bore size, and packing quantity above, then add to cart.