45# Hot Rolled Carbon Steel Round Bar, Equivalent AISI 1045 Solid Carbon Steel Round Rod

Medium carbon grade with balanced strength and toughness
Excellent hardenability for quenching & tempering heat treatment
AISI 1045 equivalent grade, widely recognized in global market
Good machinability for turning, milling and gear processing
Wide diameter range, custom cutting service available

Product Overview

45# hot rolled carbon steel round bar is a medium carbon hot rolled solid steel rod, equivalent international grade AISI 1045. It is manufactured strictly under GB/T 702, ASTM A675, EN 10060 standards. This grade features high tensile strength, good hardness performance after heat treatment and reliable machinability. The surface is black finish with mill scale from hot rolling process. It is widely used for machinery shafts, gear blanks, forging parts, connecting rods and high-load mechanical components. Custom cut lengths and official Mill Test Certificate can be provided for worldwide buyers.

Carbon Steel Round Bar

Chemical & Mechanical Property Snapshot

Item	45# (AISI 1045 Equivalent)
C (Carbon)	0.42%–0.50%
Si (Silicon)	0.17%–0.37%
Mn (Manganese)	0.50%–0.80%
P (Phosphorus)	≤0.035%
S (Sulfur)	≤0.035%
Yield Strength	≥355 MPa
Tensile Strength	≥600 MPa
Elongation	≥16%
Impact Test	Room temperature impact

Detailed Technical Specifications

Specification Item	Details
Product Name	45# Hot Rolled Carbon Steel Round Bar
Equivalent Grade	AISI 1045
Production Standard	GB/T 702, ASTM A675, EN 10060
Diameter Range	Φ10 mm – Φ300 mm
Surface Condition	Black surface with mill scale
Tolerance	Standard hot-rolling industrial tolerance
Length	3m – 12m or customized cut length
MOQ	5 Ton
Lead Time	7–15 working days after deposit
Certification	MTC, Mill Test Certificate
Package	Bundled with steel strips, seaworthy packing

Size Specification Table

Type	Diameter Range	Common Available Diameters	Standard Length	Tolerance	Cutting Service
Hot Rolled Round Bar	Φ10 mm–Φ300 mm	Φ12, Φ14, Φ16, Φ18, Φ20, Φ25, Φ30, Φ40, Φ50, Φ60, Φ80, Φ100, Φ120, Φ150, Φ200, Φ250, Φ300	6 m / 12 m	Standard hot-rolling tolerance	Custom cut-to-length & zero-cut
Cold Drawn Bright Round Bar	Φ3 mm–Φ80 mm	Φ3, Φ4, Φ5, Φ6, Φ8, Φ10, Φ12, Φ14, Φ16, Φ20, Φ25, Φ30, Φ40, Φ50, Φ60, Φ70, Φ80	6 m / 12 m	±0.02–0.05 mm	Custom cut-to-length & zero-cut

Product Comparison Table

Comparison Item	Hot-Rolled 45# Carbon Steel Round Bar	Cold-Drawn Carbon Steel Round Bar
Surface Condition	Black surface with mill scale	Smooth, bright precision surface
Available Grades	45#	1018, 1045, 20#, 45#
Equivalent International Grade	45# ≈ AISI 1045	1018 ≈ Q235B; 1045 ≈ 45#; 20# ≈ 1020; 45# ≈ 1045
Manufacturing Standard	GB/T 702, ASTM A675, EN 10060	GB/T 905, ASTM A108, EN 10278
Diameter Range	Φ10 mm–Φ300 mm	Φ3 mm–Φ80 mm
Dimensional Tolerance	Standard hot-rolling industrial tolerance	Ultra-tight tolerance ±0.02–0.05 mm
Processing Characteristics	Suitable for rough machining, forging blanks, and structural fabrication	Suitable for precision machining and finished components; reduces secondary machining
Typical Applications	Forging blanks, machinery shafts, gear blanks, connecting rods, high-load mechanical parts	Precision shafts, mechanical pins, turned & milled components, gear blanks
Recommended Selection	Select for large-diameter, medium strength, heat treatable rough-machining projects	Select for high-precision requirements, less material removal, and tight dimensional control

App Market

Reliable Steel Coil Solutions For Diverse Industrial Applications

Mechanical Shaft Components

Gear Blanks

Agricultural Machinery Parts

Product Packaging

Secure Export Packaging For Safe Handling And Delivery

FAQs

What is the equivalent grade of 45# round bar?

45# hot rolled round bar is equivalent to AISI 1045. It can replace AISI 1045 for most medium carbon machinery and forging applications.

What are the main uses of 45# carbon steel round bar?

It is widely used for machinery shafts, gear blanks, connecting rods, forging parts and high-load mechanical components.

Can 45# steel be quenched and tempered?

Yes. 45# medium carbon steel is the common material for quenching & tempering treatment to achieve higher strength and surface hardness.

Can you cut 45# round bar to custom lengths?

Yes. We provide custom cutting service according to your drawing requirements.

What is the MOQ and lead time?

MOQ is 5 tons, lead time 7–15 working days after receiving deposit.

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45# Hot Rolled Carbon Steel Round Bar, Equivalent AISI 1045 Solid Carbon Steel Round Rod