When you need the extra punch of medium-carbon steel without jumping to expensive alloys, 45# steel—known internationally as 1045—hits the sweet spot. Its 0.45 % carbon content lets it harden after heat-treatment, yet it still machines cleanly in the annealed state. Shafts, gears, pins, couplings, and heavy-duty housings made from 45# steel shrug off surface wear and moderate impact while staying budget-friendly.
At CNC Rapid we cut, turn, drill, and grind 45# steel every day. Below is a quick look at why the material performs so well and how we keep tight tolerances on every custom part that leaves our shop.
Why choose CNC-machined 45# steel parts?
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Strength without exotic pricing – Upgrades from 1018 or 12L14 mild steel cost pennies per part while doubling fatigue life.
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Reliable dimensional stability – Lower distortion during heat treatment than 4140 or 4340 alloy steels.
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Versatile finishing options – Black oxide, phosphate, nitriding, or hard chrome all bond well to 45# substrates.
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Simple weld repair – Carbon equivalent (CE) remains low enough for conventional MIG or TIG touch-ups.
Our workflow for custom 45# steel machining
1. Raw stock verification
We buy only mill-certified 1045/45# bar and plate, inspecting chemistry and hardness on arrival.
2. Rough-cut & stress-relief
Large blanks are flame-cut, then stress-relieved at 600 °C to minimize movement before finish machining.
3. Precision CNC milling & turning
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Tools: TiCN-coated end mills and CNMG inserts handle 250 m/min cutting speeds.
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Coolant strategy: High-pressure flood keeps edges under 60 °C, preserving tool life and surface integrity.
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Typical tolerances: ±0.01 mm on critical diameters, ±0.02 mm on datumed bores; tighter GD&T available on request.
4. In-house heat treatment
Quench-and-temper or induction hardening to 45–55 HRC, followed by cylindrical grinding where required.
5. Final inspection
CMM checks for position, run-out, and concentricity; surface roughness Ra ≤ 0.8 µm documented in the inspection sheet.
Common applications we ship worldwide
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Power-transmission shafts and keyed hubs
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Planetary gear sets for agricultural drives
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Hydraulic piston rods and guide rails
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Wear plates and slideways for stamping dies
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Heavy-duty bearing housings in mining equipment
If your drawing calls for medium-carbon steel and repeatable toughness, 45# steel is usually the first place to look.
Other Common Materials for CNC Machining at CNC Rapid
While 45# steel is a favorite for high-strength, medium-carbon applications, CNC Rapid also specializes in a wide variety of materials to meet your custom machining needs. Our shop handles everything from lightweight aluminum alloys to corrosion-resistant stainless steel, offering tailored solutions for any project.
Here’s a quick look at some other materials we work with:
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6061 Aluminum – Ideal for aerospace, automotive, and structural applications, 6061 aluminum provides a perfect balance of strength, weight, and corrosion resistance. Learn more about our CNC machining services for 6061 aluminum here.
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7075 Aluminum – Known for its high strength-to-weight ratio, 7075 aluminum is used in demanding applications like aircraft components and military-grade hardware. Explore CNC machining for 7075 aluminum parts here.
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304 Stainless Steel – This austenitic stainless steel offers excellent corrosion resistance, making it the material of choice for chemical, food, and medical industries. Explore CNC machining for 304 stainless steel parts here.
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Brass – Known for its machinability and corrosion resistance, brass is commonly used in electrical components and precision fittings. Find out how we handle CNC machining for brass here.
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POM (Acetal) – A highly durable plastic, POM is ideal for precision gears, bearings, and bushings. Read about CNC machining of POM here.
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Titanium – For high-performance aerospace and medical parts, titanium offers strength, lightness, and exceptional resistance to corrosion. See our CNC titanium machining solutions here.
- Copper – With excellent electrical and thermal conductivity, copper is used for high-performance electronics, heat exchangers, and plumbing components. Discover CNC machining for copper parts here.
Each material has its unique properties, and our team is ready to help you choose the right one for your next project.
Ready to move from quote to cut metal?
Send us your 2D drawings or 3D STEP files and let our team turn them into high-strength, high-precision 45# steel parts—delivered on time, every time.
We invite you to take advantage of our Metal & Plastic parts machining service, ideal for both prototypes and production needs. To receive a personalized quote, simply visit our website to get quote or reach out directly to our team at [email protected] with details of your project.
For the most accurate and speedy quote, kindly include the following in your communication:
- Part Name
- 3D Drawing
- Quantity
- Material
- Tolerance Range
- Surface Finish
We appreciate your interest and look forward to serving your machining needs. Thank you for your time!