If you’re an engineer, manufacturer, or buyer looking for a versatile low-carbon steel, 1018 cold rolled steel is likely on your radar. This material balances machinability, strength, and affordability—making it a top choice for countless industrial parts. In this guide, we’ll break down everything you need to know, from its basic definition to real-world applications, with data and examples to help you make informed decisions.
1. 1018 Cold Rolled Steel Fundamentals: What You Need to Start
Before choosing 1018 cold rolled steel, it’s critical to understand its core properties and how it’s made. Let’s start with the basics.
What is 1018 Cold Rolled Steel?
1018 cold rolled steel definition: A low-carbon steel (with ~0.18% carbon content) processed through cold rolling—where metal is pressed at room temperature after hot rolling. Unlike hot rolled steel, cold rolling creates a smoother surface and tighter dimensions.
CR 1018 basics boil down to its classification: it’s part of the AISI 1000 series, known for low carbon and excellent workability. For example, a manufacturer making small gears might choose CR 1018 over hot rolled because it requires less post-processing (like grinding) to achieve a clean finish.
Cold vs. Hot Rolled 1018: Key Differences
The main contrast lies in the manufacturing process and end properties:
- Cold rolled 1018: Processed at below recrystallization temperature (around 700°C for 1018 steel), which causes work hardening 1018—strengthening the metal but reducing ductility slightly. It has a bright, smooth surface and tight tolerances.
- Hot rolled 1018: Rolled at high temperatures, so it’s more ductile but has a rough, scaled surface. Tolerances are looser, making it better for large structural parts (e.g., beams) rather than precision components.
How is 1018 Cold Rolled Steel Made?
The cold rolling process steps for 1018 steel typically include:
- Hot rolling: First, the steel is heated and rolled into large coils or bars (the “hot rolled” stage).
- Pickling: The hot rolled steel is dipped in acid to remove scale (oxidation) from the surface.
- Cold rolling: The pickled steel is passed through rollers at room temperature to reduce thickness—this is where the cold reduction ratio (usually 50–90%) comes in (higher ratios mean thinner, stronger material).
- Skin pass rolling: A final light rolling step to improve surface smoothness and remove minor defects.
2. Mechanical & Physical Properties: Data That Matters
For engineers, 1018 CRS yield strength, tensile strength, and other properties determine if the material fits an application. Below is a table of key metrics (tested per ASTM standards):
| Property | Value | Unit | Notes |
| Tensile strength 1018 | 440–590 | MPa | Higher than hot rolled 1018 (420–550 MPa) |
| 1018 CRS yield strength | 370–480 | MPa | Critical for parts under load (e.g., shafts) |
| Elongation at break | 15–20 | % | Measures ductility (higher = more bendable) |
| Brinell hardness HRB | 70–90 | HRB | Easy to machine (hardness under 100 HRB is ideal) |
| Machinability rating | 70 | % | Based on 1018 hot rolled = 100%; lower but still excellent |
| Density 7.87 g/cm³ | 7.87 | g/cm³ | Standard for carbon steels |
| Modulus of elasticity | 205 | GPa | Stiffness (same as most carbon steels) |
| Coefficient of thermal expansion | 11.7 | μm/(m·°C) | Important for high-temperature applications |
Real-world example: A hydraulic cylinder rod manufacturer uses 1018 CRS because its yield strength (370+ MPa) can handle pressure without bending, while its elongation (15%) allows for minor adjustments during assembly.
3. Specifications & Standards: Ensuring Quality
To avoid inconsistencies, 1018 cold rolled steel must meet global standards. Below are the most common:
- AISI 1018 specification: Defines chemical composition (0.15–0.20% carbon, 0.60–0.90% manganese) and mechanical properties.
- ASTM A108 1018: Covers cold finished carbon steel bars (round, square, hex) for mechanical use.
- SAE J403 chemical limits: Matches AISI 1018’s carbon and alloy content.
- UNS G10180: Unique identifier for 1018 steel in the Unified Numbering System.
- DIN 1.0419 equivalent: European standard for low-carbon steel (similar to 1018).
- EN 10277-2: European standard for cold finished steel bars (includes grades comparable to 1018).
When buying, always ask for special bar quality (SBQ) instead of merchant quality if you need precision. SBQ has stricter tolerances and fewer defects—critical for parts like automotive pins.
4. Forms, Sizes & Tolerances: Choose the Right Shape
1018 cold rolled steel comes in multiple forms to fit different applications. Here’s a breakdown:
| Form | Common Sizes | Tolerances | Typical Use |
| 1018 cold rolled round bar | Diameter: 3–100 mm | ±0.05 mm | Shafts, spindles |
| Flat bar sizes | Thickness: 1–20 mm; Width: 10–150 mm | ±0.1 mm | Brackets, fixtures |
| Square bar stock | Side length: 5–80 mm | ±0.05 mm | Fasteners, handles |
| Hex bar | Across flats: 6–60 mm | ±0.03 mm | Precision bolts, nuts |
| CRS strip coil | Thickness: 0.3–3 mm; Width: 10–200 mm | ±0.02 mm | Sheet metal parts, springs |
| Sheet thickness 0.5–3 mm | Length: 1–2 m; Width: 1–1.5 m | ±0.05 mm | Enclosures, panels |
Most bars come with bar length 3–6 m and chamfered ends (to prevent damage during shipping). For custom sizes, many suppliers offer cutting services.
5. Surface Finish & Appearance: Why It Matters
The surface of 1018 cold rolled steel is one of its biggest advantages. Key features include:
- Smooth bright finish: No scale (unlike hot rolled steel), so it’s ready for painting or plating.
- Ra 0.2–0.6 µm: A measure of surface roughness (lower = smoother). For example, a Ra of 0.4 µm is ideal for parts that need to slide (e.g., conveyor rollers).
- Oiled surface: Most 1018 CRS comes lightly oiled to prevent rust during storage—easily cleaned with solvent.
- Scale-free and burr-free: Reduces post-processing time (e.g., no need for sanding to remove burrs).
For cosmetic parts (like bicycle frames), look for cosmetic quality 1018 CRS—it has no visible defects (e.g., scratches, edge breaks).
6. Processing & Fabrication Techniques: How to Work With 1018 CRS
1018 cold rolled steel is easy to fabricate, but following best practices ensures quality. Here’s what you need to know:
Machining
- CNC machining 1018: Perfect for precision parts (e.g., gears). Use turning feeds & speeds of 150–250 m/min (for HSS tools) to avoid overheating.
- Drilling recommendations: Use a high-speed steel (HSS) drill bit with a 118° point angle. Lubricate with cutting oil to extend tool life.
Welding
Unlike high-carbon steels, 1018 CRS requires no preheat for welding. Use MIG or TIG welding with ER70S-6 wire for strong joints. Example: A manufacturer welding hydraulic cylinder rods uses this method to avoid warping.
Other Techniques
- Case hardening carburizing: Boosts surface hardness increase (from 70 HRB to 58 HRC) for parts like gears (needs heat treatment at 920°C for 2 hours).
- Cold heading: Ideal for fasteners (e.g., bolts)—the material’s ductility allows it to be shaped without cracking.
- Bending springback: Because of work hardening 1018, expect 2–5° of springback when bending—compensate by over-bending slightly.
7. Applications & End-Use Industries: Where 1018 CRS Shines
1018 cold rolled steel is used across industries because of its versatility. Here are common applications:
- Automotive: Automotive pins, brake components, and suspension parts (e.g., a car manufacturer uses 1018 CRS for door hinge pins).
- Hydraulics: Hydraulic cylinder rods (handles high pressure and has a smooth surface for seals).
- Machinery: Spindles & shafts, gears & pinions, and fixture jigs (e.g., a factory uses 1018 CRS for CNC machine spindles).
- Power tools: Motor shafts and housing parts (balances strength and machinability).
- Consumer goods: Bicycle parts (frames, pedals) and furniture hardware (e.g., chair legs).
Yigu Technology’s Perspective on 1018 Cold Rolled Steel
At Yigu Technology, we’ve supplied 1018 cold rolled steel to over 500 manufacturers in automotive and machinery industries. We recommend 1018 CRS for clients needing precision and cost-efficiency—its consistent properties reduce production waste. For high-wear parts, we often pair it with case hardening to extend service life. Our team can help select the right form (e.g., round bar vs. strip coil) and quality grade (SBQ vs. merchant) for your project.
FAQ About 1018 Cold Rolled Steel
- Is 1018 cold rolled steel rust-resistant?
No, it’s not rust-resistant—its low carbon content means it can oxidize. To prevent rust, coat it with paint, zinc (galvanizing), or oil.
- Can 1018 CRS be heat-treated for higher strength?
Yes, but only for surface hardening (case hardening). Full heat treatment (like quenching and tempering) won’t work because of its low carbon content.
- What’s the difference between 1018 cold rolled and 1018 cold drawn steel?
1018 cold drawn steel is pulled through a die for even tighter tolerances (used for precision shafts), while cold rolled steel is pressed through rollers (better for sheets/coils). Both have similar mechanical properties.
