1045 Medium Tensile Carbon Steel Bar

1045 is a medium tensile low hardenability carbon steel generally supplied in the black hot rolled or occasionally in the normalised condition, with a typical tensile strength range 570 - 700 Mpa and Brinell hardness range 170 - 210 in either condition.Characterised by fairly good strength and impact properties, plus good machinability and reasonable weldability in the hot rolled or normalised condition.

1045 has a low through hardening capability with sections up to around 60mm only generally recommended as suitable for through hardening and tempering. It can however be successfully flame or induction hardened in the as rolled or normalised condition resulting in surface hardnesses of up to Rc 54 - Rc 60 depending upon quenching medium employed, type of set up, section size etc. Core strengths will remain as supplied.
It does not however respond satisfactorily to nitriding due to a lack of suitable alloying elements.
1045 is used extensively by all industry sectors for applications requiring more strength and wear resistance than the low carbon mild steels can provide and the higher strength of the low alloy high tensile steels is not necessary, plus those applications requiring flame or induction hardening.
Typical applications are: Axles Various, Bolts, Connecting Rods, Hydraulic Clamps and Rams, Pins Various, Rolls Various, Studs, Shafts, Spindles etc.
Colour Code Stocked Sizes
Serpentine (Bar End)

Rounds 16 mm - 690 mm Dia
Squares 25 mm - 100mm
Related Specifications
Australia AS 1442 - 1992 1045
Germany W.Nr 1.0503 C45
W.Nr 1.1191 CK45
Great Britain BS970 - Part 3 - 1991 080A47
BS970 - Part 1 - 1972 080M46
BS970 - 1955 EN43B
Japan JIS G 4051 S45C
ASTM A29/A29M - 91 1045
SAE 1045
UNS G 10450
Chemical Composition
Min. % Max. %
Carbon 0.43 0.50
Silicon 0.10 0.35
Manganese 0.60 0.90
Typical Mechanical Properties - Hot Rolled Condition
Tensile Strength Mpa 570 - 700
Yield Strength Mpa 300 - 450
Elongation in 50mm % 14 - 30
Hardness Brinell HB 170 - 210
Typical Mechanical Properties - Normalised Condition
Tensile Strength Mpa 640
Yield Strength Mpa 410
Elongation in 50mm % 22
Impact Izod J 54
Hardness HB 187
Rc 10
*Material stocked generally in the hot rolled condition but can occasionally be in the normalised condition.NB. Check the mill certificate if critical for end use.
Typical Mechanical Properties - Hardened by Water Quench at 820 oC - 850 oC or oil quench at 830 oC - 860oC and Tempered Between 540 oC - 680 oC
Section Size mm up to 16mm 17 - 40mm 41 - 100mm
Tensile Strength Mpa Min 700 650 630
Max 850 800 780
Yield Strength Mpa Min 500 430 370
Elongation in 50mm % Min 14 16 17
Impact Charpy J Average 30 30 30
Hardness HB Min 210 195 185
Max 245 235 230
Pre heat to 750 oC - 800 oC, then continue heating to 1100 oC - 1200 oC maximum, hold until temperature is uniform throughout the section and commence forging immediately.Do not forge below 850 oC

Finished forgings may be air cooled.
Heat Treatment
Heat to 800 oC - 850 oC hold until temperature is uniform throughout the section, and cool in furnace.
Flame or Induction Harderning
Heat as quickly as possible to the austenitic temperature range (820 oC - 860 oC) and required case depth followed by an immediate water or oil quench, depending upon hardness required, workpiece size/shape and quenching arrangements.The black hot rolled/normalised surface will first require to be machined sufficiently to remove any de carburised layer, otherwise less than satisfactory results will be obtained.

Following quenching to hand warm, most components should be tempered at 150 oC - 200 oC to remove quenching stresses in the case. This will have little effect on case hardness.
Heat to 820 oC - 850 oC hold until temperature is uniform throughout the section, soak for 10 - 15 minutes per 25mm of section, and quench in water or brine.
Heat to 830 oC - 860 oC soak as above and quench in oil.Temper immediately while still hand warm.
Heat to 870 oC - 920 oC hold until temperature is uniform throughout the section, soak for 10 - 15 minutes.Cool in still air.
Stress Relieving
Heat to 550 oC - 660 oC hold until temperature is uniform throughout the section, soak for 1 hour per 25mm of section, and cool in still air.
Re heat to 400 oC - 650 oC as required, hold until temperature is uniform throughout the section, soak for 1 hour per 25mm of section, and cool in still air.
Notes on Heat Treatment
Heating temperatures, rate of heating, cooling and soaking times will vary due to factors such as work piece size/shape, also furnace type employed, quenching medium and work piece transfer facilities etc.Please consult your heat treater for best results.
1045 in the hot rolled and normalised condition has very good machinability and all operations such as sawing, turning, drilling, broaching, milling and tapping etc. can be carried out satisfactorily using machine manufacturers recommendations for suitable tool type, feeds and speeds.
1045 is readily weldable in the as rolled and normalised condition providing the correct procedure is employed.Following welding the work piece immediately upon cooling to hand warm should be stress relieved at 550 oC - 660 oC if possible.

NB. Welding in the hardened and tempered, flame or induction hardened condition is not recommended.
Welding Procedure
Welding of 1045 should always be carried out using low hydrogen electrodes.Please consult your welding consumables supplier.
Suggested Pre-heat Temperature
Section 25mm 50mm 75mm 150mm +
oC 100 140 200 300
Post Welding
Cool as slowly as possible in dry lime, sand etc.
Interlloy believes the information provided is accurate and reliable. However no warranty of accuracy, completeness or reliability is given, nor will any responsibility be taken for errors or omissions.