AISI/SAE 1045 cold-rolled coil is a medium-carbon, high-strength carbon steel commonly supplied in coil form for precision parts, shafts, gears, and structural components where a balance of strength, toughness, and machinability is required. When supplied in cold-rolled condition, 1045 delivers tighter thickness tolerances, improved surface finish, higher yield strength, and better dimensional consistency than hot-rolled material; it is readily heat-treated to reach a wide range of mechanical properties. For buyers seeking factory-direct supply from China, MWAlloys offers 100% factory pricing with available stock and rapid shipment for standard coil sizes.

What is 1045 steel?

1045 is a medium-carbon plain carbon steel in the SAE/AISI designation series. Its carbon content puts it in the range that allows good balance between strength and ductility while permitting through-hardening by conventional heat treatment. Cold rolling produces coils with improved surface quality and closer dimensional control compared with hot-rolled coils, and that makes 1045 cold-rolled coil attractive for fabrications that need a finished surface and predictable mechanical performance.

Chemical composition (nominal / typical ranges)

Source technical data and typical composition ranges are consistent with standard data sheets for SAE/AISI 1045.

Material properties

Note: Property values depend strongly on heat treatment (annealed, normalized, quenched & tempered). The table below gives representative values for cold-rolled, normalized and quenched-and-tempered conditions used by designers.

These ranges align with standard datasheets and engineering tables for 1045/C45 grade steels; final selection must use supplier certification values for design calculations.

Typical specifications & coil dimensions

For final procurement, always request a material test certificate (MTC) and dimensional tolerance sheet from the mill.

International equivalents

Cross-reference tables and conversion charts from international steel directories show direct equivalence between SAE 1045 and EN C45 family grades; minor chemistry or delivery condition differences may exist and must be confirmed for critical applications.

Cold rolling: production effects on microstructure and properties

Cold rolling reduces thickness by plastic deformation at ambient temperature and produces:

• Strain-hardened microstructure near the surface and through thickness depending on reduction ratio; cold rolling increases yield strength and hardness relative to the annealed/hot-rolled state.

• Improved surface finish and closer thickness tolerances, which reduces downstream machining and finishing costs.

• Residual stresses introduced by cold working; these can be relaxed by light annealing or temper rolling to control flatness and mechanical behavior.

• Anisotropy in mechanical properties (directional differences) — mill certification should indicate rolling direction properties where important.

Designers must consider that heavy cold reduction reduces ductility; typical practice is to perform a light anneal or tempering sequence before tight-tolerance finishing if component forming is required later. (Industry reference material on cold-rolling effects supports these points.)

Heat treatment: common cycles and expected outcomes

Annealing (softening): Heat to ~680–720°C, hold to homogenize, furnace cool or controlled cool to obtain a soft ferrite-pearlite microstructure — results: improved machinability and ductility; hardness drops to annealed levels.
Normalizing: Heat to 840–880°C and air-cool — refines grain size; used when improved toughness and uniform microstructure needed.
Quenching & tempering: Hardening by heating to 820–860°C, quench (oil/water) then temper at 400–650°C depending on required hardness/toughness balance — widely used to reach higher tensile strengths and wear resistance.

Because a cold-rolled coil is often supplied in a deformed/strain-hardened state, mills may offer mill annealed coils (soft) or skin-passed coils (slight temper rolling) according to buyer needs. Material certification should include post-treatment condition.

Machinability, weldability and joining notes

• Machinability: 1045 has moderate machinability; it machines well when annealed but becomes more difficult after hardening. For high volume turning, specifying a free-machining variant (sulfur added) may be preferable.

• Welding: Welding of 1045 requires preheating and controlled interpass temperatures to avoid cold cracking and loss of toughness due to high carbon content. Post-weld heat treatment (PWHT) is recommended for critical weldments.

• Brazing/fastening: Standard joining methods apply, but threads and minor features are often rolled or cut from normalized material to avoid work-hardening issues.

Provide weld procedure specifications from the purchaser for critical assemblies; mill MTCs may include recommended practices.

Typical applications

• Shafts, axles, spindles, and tie rods

• Gears, pins, and couplings (after appropriate heat treatment)

• Machinery components requiring higher strength than low-carbon steels

• Cold-formed parts where improved surface finish is mandated

• Automotive parts (non-safety critical) and heavy equipment components

Because of its balance between strength, machinability and cost, 1045 is a staple material in mechanical engineering applications.

Surface finish, tolerance control and inspection checkpoints

Buyers should inspect or require certificates for:

• Surface condition (scratches, decarburization, scale removed)

• Thickness tolerance (mill sheet/tolerance chart)

• Width and camber tolerances

• Mechanical test results (UTS, yield, elongation) — certified by supplier MTC

• Chemical analysis (spectro report) confirming C, Mn and impurity limits

• Flattening and residual stress reports for high-precision strips

Cold-rolled coils are typically shipped with protective inner/outer wraps, and in seaworthy packaging for export. Ask the mill for photographs and test certificates before shipping if quality control is critical.

2025 price comparison (US / Europe / China)

Context and caveats: Coil prices fluctuate with scrap values, energy costs, tariffs and regional demand. Cold-rolled coil (CRC) typically trades at a premium to hot-rolled coil (HRC) because of added processing. The figures below summarize market spot ranges in 2025 from industry trackers and trade commentary; use them for budgeting, not final procurement.

How to interpret:

• The US and EU prices carry higher processing, labor and logistics costs and sometimes policy-driven premiums.

• Chinese mill export offers often undercut Western domestic prices — this is the reason many international buyers source factory-direct from Chinese producers (subject to duties and quality checks).

• Cold rolled coil for 1045 (medium carbon) may see additional mill premiums for tighter chem spec and special finishing.

Recommendation: Request firm quotations (FOB/CIF) from multiple mills and ask for current scrap-linked index basis to benchmark offers.

Purchasing tips, packing and MWAlloys offering

Purchasing checklist

1. Confirm exact chemistry and delivery condition (annealed, normalized, skin-passed).

2. Obtain Mill Test Certificate (EN 10204 3.1 or equivalent) with batch spectro analysis.

3. Specify coil geometry: width, thickness, ID, weight and surface finish.

4. Ask for sample pieces or photos and check for surface defects or decarburization.

5. Define acceptance tests (UTS, yield, elongation, hardness) and inspection sampling plan.

Packing & shipping

• Coils normally wrapped, strapped, and placed on wooden or steel saddles inside containers or on flat racks for ocean freight.

• For export, ask for anticorrosive wrapping if long transit or humid conditions expected.

MWAlloys offering (factory proposition)
MWAlloys is a Chinese mill-partnered supplier focusing on ferrous products. For 1045 cold-rolled coil, MWAlloys can provide:

• 100% factory ex-works pricing (no reseller markup).

• Standard coil sizes in stock for quick release.

• Mill Test Certificate (3.1/3.2 as required), chemical & mechanical test reports.

• Quick shipment capability from nearest Chinese port; options for FOB or CIF to buyer’s port.

• Custom finishing services (light anneal, skin-pass, slitting) available on request.

FAQs

1. Is 1045 suitable for shafts that will be heat treated?
   Yes — 1045 responds well to quench & temper; it is commonly used for shafts after proper heat treatment to reach required hardness and fatigue strength.

2. What is the main difference between 1045 cold-rolled coil and hot-rolled coil?
   Cold-rolled coil offers tighter thickness tolerance, better surface finish and higher yield strength due to strain hardening; hot-rolled is cheaper and thicker with mill scale.

3. Can 1045 be welded without preheat?
   For thicker sections or critical welds, preheating and PWHT are recommended because of the medium carbon level. For thin gauge cold-rolled strip, welding is possible with careful procedure.

4. Which international grade equals SAE 1045?
   Common equivalents: EN C45 (1.0503/1.1191), JIS S45C, China grade 45#. Verify supplier certs for tight interchangeability.

5. What hardness range should I expect for mill-annealed cold-rolled 1045?
   Typical Brinell hardness for annealed/soft condition is roughly 150–220 HB; quenched and tempered conditions produce higher values depending on temper.

6. Are there corrosion limitations for 1045?
   1045 is not stainless; corrosion protection (painting, plating, galvanizing) must be specified for outdoor or corrosive environments.

7. How do cold-rolling reductions affect mechanical properties?
   Larger cold reductions increase yield strength and reduce elongation. If ductility is required downstream, specify reduced cold work or order annealed coils.

8. How accurate are 2025 price ranges?
   They are spot-range indications derived from industry trackers for CRC in mid-2025; for firm procurement, request live quotes.

9. Can I get slitted strips or cut-to-length sheets from 1045 CRC?
   Yes — mills offer slitting and cut-to-length services; specify slit widths, burr control and edge finish.

10. What test certificates should I insist on?
    Ask for EN 10204-3.1 or equivalent MTC, spectro chemical analysis, tensile test report and hardness values for the shipped batch.

Authoritative references

• MatWeb — SAE/AISI 1045 datasheet (composition and properties)
• AZoM — AISI 1045 Medium Carbon Steel (technical overview)
• SteelBenchmarker — price history & market data (steel indices)