45# – JIS:S45C/S48C Carbon Steel Pipe Krobo Steel

Product Introduction 

45# steel pipe has a carbon content of about 0.45%, contains a small amount of manganese, silicon, etc., and is a high-quality carbon structural steel with low sulfur and phosphorus content.

(GB/T14975-2002) is a hot-rolled (extrusion, expansion) and cold-drawn ( rolled).


heat treatment:Recommended heat treatment temperature: normalizing 850, quenching 840, tempering 600.No. 45 steel is a high-quality carbon structural steel with low hardness and easy cutting. It is often used in molds to make templates, pins, guide posts, etc., but heat treatment is required.


  1. No. 45 steel is qualified if its hardness is greater than HRC55 (up to HRC62) after quenching but before tempering. The highest hardness for practical application is HRC55 (high frequency quenching HRC58).
  2. Do not use the heat treatment process of carburizing and quenching for No. 45 steel. After quenching and tempering, the parts have good comprehensive mechanical properties and are widely used in various important structural parts, especially those connecting rods, bolts, gears and shafts that work under alternating loads. But the surface hardness is low and not wear-resistant. Tempering + surface quenching can be used to improve the surface hardness of parts.


Carburizing treatment is generally used for heavy-duty parts with wear-resistant surface and impact-resistant core, and its wear resistance is higher than quenching and tempering + surface quenching. The surface carbon content is 0.8–1.2%, and the core part is generally 0.1–0.25% (0.35% is used in special cases). After heat treatment, the surface can obtain very high hardness (HRC58–62), and the core has low hardness and impact resistance.

If No. 45 steel is used for carburizing, hard and brittle martensite will appear in the core after quenching, and the advantages of carburizing treatment will be lost. Now the materials using carburizing process, the carbon content is not high, and the core strength can reach very high when it reaches 0.30%

45# Carbon Steel Chemical Composition:

Element Composition (%)
Carbon (C) 0.42-0.50
Silicon (Si) 0.17-0.37
Manganese (Mn) 0.50-0.80
Phosphorus (P) ≤0.035
Sulfur (S) ≤0.035
Chromium (Cr) ≤0.25
Nickel (Ni) ≤0.30
Copper (Cu) ≤0.25



45# steel is a commonly used medium-carbon quenched and tempered steel, with good comprehensive mechanical properties, low hardenability, and cracks are prone to occur during water quenching. Small parts should be quenched and tempered, and large parts should be normalized. It is mainly used to manufacture high-strength moving parts, such as turbine impellers and compressor pistons. Shafts, gears, racks, worms, etc.

Classification By Size:

The length is generally 6000mm, 1250mm,2200mm,12000mm, and the thickness is distinguished by cold rolling and hot rolling. Cold rolling mainly has thickness 1.0mm, 1.2mm, 1.5mm, 2.0mm, 2.5mm, 3.0mm. The main thickness of hot rolling is 3.0mm, 4.0mm, 6.0mm, 8.0mm, 10.0mm, and the width is generally 1000mm, 1219mm, 1500mm.Please contact customer service for general specifications.


Hot-rolled carbon steel pipe are produced by continuous hot-rolled carbon steel technology with hot-rolled steel strip or cold-rolled steel strip as the substrate. The hot-rolled carbon steel sheet is supplied as a rectangular flat plate by cross-cutting; the hot-rolled carbon steel sheet is supplied in coil form by coiling, and the hot-rolled carbon steel sheet coil can be divided into hot-rolled carbon steel sheet coil and cold-rolled carbon steel sheet Coils, they are mainly used in construction, home appliances, automobiles, containers, transportation and household business and other fields. Especially steel structure construction, automobile manufacturing, steel silo manufacturing and other industries.


Their main features are: strong corrosion resistance, good appearance quality, benefit from deep processing, economical and practical, etc.

Application range:

(1)After annealing, it is processed into ordinary cold rolling;

(2) The galvanizing unit with pre-annealing treatment device processes galvanizing;

(3) Panels that basically do not need to be processed.

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