Mechanical properties

Tensile and yield strength of carbon and alloy steel: 1018, 1045, 4130, 4140, 4340

Carbon steel 1045 (AISI/SAE 1045, UNS G10450) hot rolled bar has a specified minimum yield strength of 300 MPa and a tensile strength of 570 to 700 MPa, per the voestalpine datasheet. Alloy steel 4140 (AISI/SAE 4140, UNS G41400) quenched and tempered bar of 10 to 100 mm has a specified minimum yield strength of 740 MPa and a tensile strength of 930 to 1,080 MPa, per the voestalpine datasheet.

No steel grade has one strength, because each is sold in several conditions and the condition sets the number. In our nine steel profiles the sourced yield strengths run from 170 MPa (Carbon steel 1010, as-welded ERW round mechanical tube, per MWAlloys; a typical range) to 1,330 MPa (Alloy steel 4130, quenched and tempered, per the Sandia hydrogen compatibility reference). Alloy steel 4340 alone spans 665 to 1,125 MPa minimum yield between conditions T and Z, per voestalpine. Yield strength is the stress at which steel starts to deform permanently; tensile strength is the highest stress it carries before breaking (general engineering knowledge, not in our data).

Space Mushroom · data checked 1 November 2026 · nine steel profiles, 51 records · download the data (CSV)

What are the yield and tensile strengths of A36, 1018, 1045, 4130, 4140 and 4340 steel?

In our data, hot rolled carbon steel 1045 has a specified minimum yield strength of 300 MPa per voestalpine, cold drawn carbon steel 1018 has 370 MPa per Elgin (basis not stated), and quenched and tempered alloy steel 4140 of 10 to 100 mm has 740 MPa per voestalpine. ASTM A36 has a 250 MPa minimum per Wikipedia. The cards below give each grade's figures in MPa with condition, basis and source.

Where a source printed psi or ksi, the profile keeps the original and this page converts it to MPa. Each card heading links to the grade's profile, which lists every source.

ASTM A36 (UNS K02600)

Plate, SSAB tableyield strength min 248 MPa · tensile strength 400 to 552 MPaper SSAB
Plates, bars, shapes under 8 in (Wikipedia)yield strength min 250 MPa · tensile strength 400 to 550 MPaper Wikipedia

Neither source names how the steel was made, so A36 sits in the "other or not stated" column of the matrix.

Carbon steel 1018 (AISI/SAE 1018, UNS G10180)

Hot rolledyield strength 240 MPa · tensile strength 430 MPaper MfgRobots
Cold drawnyield strength 370 MPa · tensile strength 440 MPaper Elgin

Single values with no stated basis. No minimum from a standard in our data.

Carbon steel 1045 (AISI/SAE 1045, UNS G10450)

Hot rolled, specifiedyield strength min 300 MPa · tensile strength 570 to 700 MPaper voestalpine
Cold drawn under 16 mm, specifiedyield strength min 540 MPa · tensile strength min 690 MPaper voestalpine
Normalised, typicalyield strength 400 MPa (typical) · tensile strength 600 MPa (typical)per Metal Supermarkets

No quenched and tempered figure found.

Alloy steel 4130 (AISI/SAE 4130, UNS G41300)

Normalisedyield strength 435 MPa · tensile strength 670 MPaper MatWeb
Cold drawn tube, AMS 6371yield strength 483 MPa (typical) · tensile strength 655 MPa (typical)per Aircraft Materials
Quenched and tempered, AMS 6346 baryield strength 689 MPa (typical) · tensile strength 862 MPa (typical)per Aircraft Materials

A laboratory compilation shows 635 to 1,330 MPa yield for other heat treatments.

Alloy steel 4140 (AISI/SAE 4140, UNS G41400)

Quenched and tempered, 10 to 100 mm, specifiedyield strength min 740 MPa · tensile strength 930 to 1,080 MPaper voestalpine
Quenched and tempered, 101 to 250 mm, specifiedyield strength min 665 MPa · tensile strength 850 to 1,000 MPaper voestalpine
Normalised, 25 mm roundyield strength 655 MPa · tensile strength 1,020 MPaper Elgin

No annealed strength found.

Alloy steel 4340 (AISI/SAE 4340, UNS G43400)

Quenched and tempered, condition U (100 mm), specifiedyield strength min 740 MPa · tensile strength 930 to 1,080 MPaper voestalpine
Quenched and tempered, condition Z (30 mm), specifiedyield strength min 1,125 MPa · tensile strength min 1,550 MPaper voestalpine
Annealed at 810 °Cyield strength not printed · tensile strength 744.6 MPaper eFunda

Conditions T to Z run from 665 to 1,125 MPa minimum yield.

How does the strength of each steel change with its condition?

Strength changes more with condition than with grade. Cold drawn carbon steel 1045 under 16 mm has a specified minimum yield strength of 540 MPa against 300 MPa hot rolled, per voestalpine, and alloy steel 4340 runs from 665 to 1,125 MPa across conditions T to Z, per voestalpine. The condition matrix shows all nine grades by condition; an empty cell means no source figure exists.

Rows are grades, columns are the condition the source named. A cell shows the range of the figures in it; select a cell to see each record, its size or section, its basis and its source. A cell marked not found means no source we hold gives a figure for that grade in that condition. We left those cells empty on purpose: a figure from another condition would be wrong.

Hot rolled: shaped while red hot, no further cold work
Cold drawn: pulled through a die at room temperature; stronger, less ductile
Annealed: heated and slowly cooled to soften it
Normalised: heated, then cooled in still air
Quenched and tempered (Q&T): hardened by fast cooling, then reheated to trade hardness for toughness
Specified minimum: the value the supplier or standard guarantees; a typical value is not a guarantee

Show in the matrix Yield strengthTensile strengthYield ÷ tensileHardness

Select a column heading to sort the rows by that condition. Select it again to reverse, a third time to reset.

Strength of nine steel grades by condition. Rows are grades, columns are conditions. Empty cells mean no source figure was found.
Grade
A36structural	not found in any source we hold	not found in any source we hold	not found in any source we hold	not found in any source we hold	not found in any source we hold
1010carbon			not found in any source we hold		not found in any source we hold
1018carbon			not found in any source we hold	not found in any source we hold	not found in any source we hold	none for this grade
1045carbon					not found in any source we hold	none for this grade
1070carbon	not found in any source we hold	not found in any source we hold	not found in any source we hold	not found in any source we hold	not found in any source we hold
1215carbon	not found in any source we hold		not found in any source we hold	not found in any source we hold	not found in any source we hold
4130alloy	not found in any source we hold					none for this grade
4140alloy	not found in any source we hold	not found in any source we hold	not found in any source we hold			none for this grade
4340alloy	not found in any source we hold	not found in any source we hold		not found in any source we hold		none for this grade

Values are in MPa, except yield ÷ tensile (a ratio) and hardness (HB, or HRC where the source printed no HB).

Shading runs from the lowest to the highest cell in the view you picked. The printed number is what counts; shading is only a guide. A cell that mixes a minimum and a typical value shows both labels.

1045 · Hot rolled 2 records

hot rolled · under 250 mm

Yield
min 300 MPa

Tensile
570 to 700 MPa range as printed

Yield ÷ tensile
0.43 to 0.53 computed

Hardness
170 to 210 HB range as printed

Elongation
min 14 %

Source: voestalpine High Performance Metals: AISI 1045 / 1.1191 / G10430 datasheet (Australia) (Mechanical Properties (reference) table, Rolled column, Yield Strength row)
as rolled (hot rolled bar) · bar (page section C1045 Bar Products)

Yield
59,000 psi (407 MPa) typical

Tensile
90,000 psi (621 MPa) typical

Yield ÷ tensile
0.66 computed

Elongation
26 % typical

Source: Metal Supermarkets: Hot Rolled Steel C1045 grade summary (Typical Mechanical Properties table, As Rolled column, Yield Point row)

Coverage is thin where people most want it. Of 45 cells for the five named conditions, 16 hold both a yield and a tensile figure and 27 hold nothing at all. The carbon steels have no quenched and tempered figure in our data, and only 1045 has both an annealed yield and an annealed tensile figure.

Which steels does this page cover, and what are their designations?

This page covers nine steels from the Space Mushroom database: structural steel ASTM A36, carbon steels 1010, 1018, 1045, 1070 and 1215, and alloy steels 4130, 4140 and 4340. The table gives each steel's designations as printed in its profile, and the number of strength, hardness or elongation records that the page uses for it.

Steels covered, with designations from each profile and the number of records used
Steel (profile)	AISI / SAE number	UNS number	EN designation	Records on this page
ASTM A36	not listed	K02600	not listed	5
Carbon steel 1010	1010	G10100	not listed	6
Carbon steel 1018	1018	G10180	1.0401 (nearest equivalent), 1.0453, C15	2
Carbon steel 1045	1045	G10450	1.0503 (nearest equivalent), C45	7
Carbon steel 1070	1070	G10700	1.1231 (listed as equivalent to AISI 1070)	3
Carbon steel 1215	1215	G12150	not listed	2
Alloy steel 4130	4130	G41300	1.7218 (nearest equivalent), 25CrMo4	9
Alloy steel 4140	4140	G41400	1.7225, 42CrMo4	8
Alloy steel 4340	4340	G43400	1.6565 (nearest equivalent), 1.6582 (nearest equivalent), 40NiCrMo6, 34CrNiMo6	9

What does heat treatment change in steel, and what does it not?

Heat treatment and cold work change the strength, hardness and ductility of steel, but not its stiffness. In our data, alloy steel 4340 rises from 665 MPa minimum yield strength at condition T to 1,125 MPa at condition Z, per voestalpine, while the elastic modulus of all nine steels stays between 190 and 210 GPa.

What it changes

Strength. Alloy steel 4340 steps from 665 MPa minimum yield strength at condition T to 1,125 MPa at condition Z, a factor of 1.7 within one grade, per voestalpine. Cold drawn carbon steel 1045 under 16 mm has a minimum yield strength of 540 MPa against 300 MPa hot rolled, 1.8 times higher, per voestalpine.
Ductility. The price shows in elongation. Hot rolled carbon steel 1045 has a minimum elongation of 14 % and cold drawn 8 % (A5 gauge), per voestalpine. For alloy steel 4340 the minimum elongation falls from 13 % at condition T to 5 % at Z, per voestalpine.
Toughness. The voestalpine datasheet gives alloy steel 4340 a minimum impact energy of 35 J at T, 42 J at U and 9 J at Z.
Hardness. It rises with strength: alloy steel 4340 is 248 to 302 HB at T and at least 444 HB at Z, per voestalpine.

What it does not change

Stiffness. The elastic modulus in our nine profiles sits between 190 and 210 GPa for every grade, from ASTM A36 to alloy steel 4340, whatever the strength (14 records, various sources). A stronger steel is not a stiffer one. See stiffness compared across materials.
Section size. Heat treatment reaches less deeply into a thick bar (general engineering knowledge, not in our data), and our figures show the effect. Alloy steel 4140 quenched and tempered drops from 740 MPa minimum yield strength at 10 to 100 mm to 665 MPa at 101 to 250 mm per voestalpine, and the Aircraft Materials typical yields fall from 770 MPa at 50 mm to 570 MPa at 200 mm.
The grade's ceiling. No heat treatment turns 1018 into 4340 (general engineering knowledge, not in our data). None of the carbon steels has a quenched and tempered strength in our data, while all three alloy grades do.

One grade, seven conditions: 4340 quenched and temperedMinimum yield rises from 665 to 1,125 MPa as the condition letter goes up, while the minimum elongation falls from 13 % to 5 %.

Condition Truling section 150 mm

min 665

850 to 1,000

248 to 302 HB · elongation min 13 % · impact min 35 J

Condition Uruling section 100 mm

min 740

930 to 1,080

269 to 331 HB · elongation min 12 % · impact min 42 J

Condition Vruling section 63 mm

min 835

1,000 to 1,150

293 to 352 HB · elongation min 12 % · impact min 42 J

Condition Wruling section 30 mm

min 925

1,080 to 1,230

311 to 375 HB · elongation min 11 % · impact min 35 J

Condition X*ruling section 30 mm

min 1,005

1,150 to 1,300

341 to 401 HB · elongation min 10 % · impact min 28 J

Condition Y*ruling section 30 mm

min 1,080

1,230 to 1,380

363 to 429 HB · elongation min 10 % · impact min 20 J

Condition Z*ruling section 30 mm

min 1,125

min 1,550

min 444 HB · elongation min 5 % · impact min 9 J

04008001,2001,600MPa

Source: voestalpine datasheet. Each condition is tied to a limiting ruling section (150 mm for T down to 30 mm for W to Z), and the datasheet gives one tempering range for all of them, so the tempering temperature behind each row is not stated. Conditions marked * are typically ordered annealed for machining, then heat treated. At Z the tensile figure is a minimum, not a range.

Text version of this chart (table, values in MPa)

One grade, seven conditions: 4340 quenched and tempered: yield strength and tensile strength in MPa, with basis and source
Condition	Yield strength (MPa)	Tensile strength (MPa)	Hardness, elongation, impact energy	Source
Condition T ruling section 150 mm	min 665 minimum	850 to 1,000 range as printed	248 to 302 HB · elongation min 13 % · impact min 35 J	voestalpine
Condition U ruling section 100 mm	min 740 minimum	930 to 1,080 range as printed	269 to 331 HB · elongation min 12 % · impact min 42 J	voestalpine
Condition V ruling section 63 mm	min 835 minimum	1,000 to 1,150 range as printed	293 to 352 HB · elongation min 12 % · impact min 42 J	voestalpine
Condition W ruling section 30 mm	min 925 minimum	1,080 to 1,230 range as printed	311 to 375 HB · elongation min 11 % · impact min 35 J	voestalpine
Condition X* ruling section 30 mm	min 1,005 minimum	1,150 to 1,300 range as printed	341 to 401 HB · elongation min 10 % · impact min 28 J	voestalpine
Condition Y* ruling section 30 mm	min 1,080 minimum	1,230 to 1,380 range as printed	363 to 429 HB · elongation min 10 % · impact min 20 J	voestalpine
Condition Z* ruling section 30 mm	min 1,125 minimum	min 1,550 minimum	min 444 HB · elongation min 5 % · impact min 9 J	voestalpine

Is a steel strength figure a minimum or a typical value?

It can be either, and the two make different promises. For hot rolled carbon steel 1045, voestalpine specifies a minimum yield strength of 300 MPa, while Metal Supermarkets prints a typical as-rolled yield strength of 407 MPa, 1.36 times higher. A specified minimum is the value a supplier or standard guarantees; a typical value is only what test bars usually show (general engineering knowledge, not in our data).

Both figures are correct for their purpose. Using the typical figure as a design limit would take credit for strength nobody promised.

Seven records for one grade: 1045 yield and tensile strengthSolid yield bars are specified minimums, hatched bars are typical values. The minimum for hot rolled bar is 300 MPa; the typical as-rolled figure is 407 MPa.

Hot rolledvoestalpine, specified

min 300

570 to 700

Cold drawn, under 16 mmvoestalpine, specified

min 540

min 690

Cold drawn, 16 to 38 mmvoestalpine, specified

min 510

min 650

Cold drawn, 38 to 63 mmvoestalpine, specified

min 500

min 640

As rolled (hot rolled bar)Metal Supermarkets, typical

407 typical

621 typical

NormalisedMetal Supermarkets, typical

400 typical

600 typical

AnnealedMetal Supermarkets, typical

331 typical

552 typical

0200400600800MPa

Same grade, different conditions and bases: cold drawn and hot rolled minimums are from voestalpine (cold drawn is listed by bar size); as rolled, normalised and annealed are typical values from a reseller, Metal Supermarkets, printed in psi. Cold drawn and hot rolled voestalpine tensile figures are a minimum and a printed range. No quenched and tempered 1045 figure was found.

Text version of this chart (table, values in MPa)

Seven records for one grade: 1045 yield and tensile strength: yield strength and tensile strength in MPa, with basis and source
Condition	Yield strength (MPa)	Tensile strength (MPa)	Source
Hot rolled voestalpine, specified	min 300 minimum	570 to 700 range as printed	voestalpine
Cold drawn, under 16 mm voestalpine, specified	min 540 minimum	min 690 minimum	voestalpine
Cold drawn, 16 to 38 mm voestalpine, specified	min 510 minimum	min 650 minimum	voestalpine
Cold drawn, 38 to 63 mm voestalpine, specified	min 500 minimum	min 640 minimum	voestalpine
As rolled (hot rolled bar) Metal Supermarkets, typical	407 typical typical	621 typical typical	Metal Supermarkets
Normalised Metal Supermarkets, typical	400 typical typical	600 typical typical	Metal Supermarkets
Annealed Metal Supermarkets, typical	331 typical typical	552 typical typical	Metal Supermarkets

Sources differ on the same steel. A36 plate: SSAB prints 36 ksi (248 MPa) minimum yield and Wikipedia prints 250 MPa for the same minimum, converted and rounded. Plate over 8 in drops to 220 MPa. A36 tensile is a range of 400 to 550 MPa, so a mill report anywhere in that band is within specification.
A minimum can hide the range. Alloy steel 4140 quenched and tempered at 10 to 100 mm has a minimum yield strength of 740 MPa but a tensile band of 930 to 1,080 MPa per voestalpine, a spread of 150 MPa that the minimum does not show.
Temperature changes minimums too. Wikipedia gives ASTM A36 a minimum tensile strength of 370 MPa at 700 °F and 260 MPa at 800 °F, below its room-temperature minimum. Those two records are in the data table but not in the matrix, which is room temperature only.
Test environment matters. One alloy steel 4140 tensile strength in our data (1,228 MPa, per the Sandia hydrogen compatibility reference) was measured in 69 MPa hydrogen gas, so it is an environment test and is kept out of the matrix.

What does this mean in practice when choosing or ordering steel?

Order steel by grade, condition and size, and design on the specified minimum for that condition. Cold drawn carbon steel 1045 under 16 mm has a specified minimum yield strength of 540 MPa, and bar of 38 to 63 mm has 500 MPa, per voestalpine, so one grade changes with bar size. The six cases below apply this.

Buying bar for a shaft or axle. Cold drawn carbon steel 1045 has a minimum yield strength of 540 MPa under 16 mm, with bigger bars lower, per voestalpine: 510 MPa at 16 to 38 mm and 500 MPa at 38 to 63 mm. The strength depends on the bar's size as well as its grade. See the 1045 vs 4140 comparison.
Needing high strength in a thick section. Choose an alloy grade ordered quenched and tempered to a named condition, such as alloy steel 4340 condition V (835 MPa minimum yield strength at a 63 mm ruling section) or alloy steel 4140 at 10 to 100 mm (740 MPa), both per voestalpine. Then check what toughness the condition keeps: condition Z has a 9 J minimum impact energy against 42 J at U, per voestalpine.
Structural plate and shapes. ASTM A36 has a 250 MPa minimum yield strength per Wikipedia. Its figures are specified minimums and ranges, not typical values. How A36 is made is not stated in our sources.
Machining stock. Carbon steel 1215 (free-machining) bar, cold drawn, has 415 MPa yield strength and 540 MPa tensile strength per Budind, hardness 167 HB. We found no hot rolled 1215 value.
Reading a hardness number. Hardness tracks strength within a grade: alloy steel 4140 quenched and tempered at 10 to 100 mm has 269 to 331 HB with a tensile strength of 930 to 1,080 MPa, per voestalpine. The hardness scales article explains Brinell and Rockwell. We hold no conversion table, so we do not convert between them.
Welding or reheating. Welding and heating after delivery can change the condition locally (general engineering knowledge, not in our data), so a supplier's figure applies to the steel as supplied.

Choosing between grades rather than conditions: which carbon or alloy steel, A36 vs 1018, 1018 vs 4140, 4130 vs 4140.

What do we not know about steel strength yet?

We found no quenched and tempered strength for carbon steels 1018, 1045 or 1215, no annealed strength for alloy steels 4130 or 4140, and no normalised strength for alloy steel 4340 in any source we hold. Almost every figure is a datasheet minimum, a typical value or a printed range, not a measured batch result. The list below gives the detail.

Quenched and tempered carbon steel. No value for 1018, 1045 or 1215. A Saarstahl sheet for C45, the European near-equivalent of 1045, has quenched and tempered values, but it is a different grade, so we do not use it.
Annealed and normalised alloy steel. No annealed yield or tensile for 4130 or 4140, no normalised value for 4340, and for annealed 4340 only a tensile figure of 744.6 MPa and a hardness of 217 HB (its yield is printed without a condition, so we do not use it). The annealed 4130 bar hardness is printed in the source as 29 HB maximum, which is implausible for steel and probably a typo; it is left out of the matrix.
Standard minimums. We did not reach the text of ASTM A36, A29, A108 or A519. A36 minimums come from SSAB and Wikipedia, not from the standard.
Measured values. Almost every figure is a datasheet minimum, a typical value or a printed range. Our data has no measured batch results or mill certificates.
1070 and 1010. 1070 strength is printed without a condition (supplier minimum 390 MPa, a database value of 495 MPa, never reconciled). 1010 has hot rolled and cold drawn single values and tube ranges, but no annealed bar.
Other grades. 1020, 4150, 8620 and others people search for are not in our database yet. Nor are fatigue strength, fracture toughness, welds and elevated-temperature curves beyond the two A36 points.
Review. Every profile is a draft read by an AI assistant from the sources it cites. A named engineer has not signed this article.

All 51 records with condition, basis and source

Every yield, tensile and hardness record behind the matrix
Grade	Condition	As printed	Size or form	Yield (MPa)	Tensile (MPa)	Hardness	Source
A36	Other or not stated	condition not stated	mill plate and temper-leveled plate (SSAB product table); 0.100 to 6.00 in (2.54 to 152 mm)	min 36 ksi (248 MPa) minimum	58 to 80 ksi (400 to 552 MPa) range as printed		SSAB: ASTM A36 structural steel product page
A36	Other or not stated	condition not stated	plates, bars and shapes; less than 8 in (203 mm)	min 250 MPa minimum	400 to 550 MPa range as printed		Wikipedia: A36 steel
A36	Other or not stated	condition not stated	plates; more than 8 in (203 mm)	min 220 MPa minimum	not printed		Wikipedia: A36 steel
A36	Other or not stated	condition not stated Not in the matrix: tested at 700 °F (371 °C), not room temperature	bars and shapes at 700 °F (371 °C)	not printed	min 370 MPa minimum		Wikipedia: A36 steel
A36	Other or not stated	condition not stated Not in the matrix: tested at 800 °F (427 °C), not room temperature	bars and shapes at 800 °F (427 °C)	not printed	min 260 MPa minimum		Wikipedia: A36 steel
1010	Hot rolled	hot rolled		190 MPa basis not stated	350 MPa basis not stated		MfgRobots: AISI 1010 Hot Rolled Steel, Properties and Applications (article 35862)
1010	Cold drawn	cold drawn		330 MPa basis not stated	400 MPa basis not stated		MfgRobots: AISI 1010 Cold Drawn Steel (article 35889)
1010	Normalised	normalized round mechanical tube		275 to 345 MPa typical	345 to 450 MPa typical		MWAlloys: M1010 Round Mechanical Carbon Steel Tube (technical article, 2026-02-06)
1010	Other or not stated	form not stated		not printed	not printed	95 to 105 HB	Total Materia: AISI 1010 Structural and constructional steels (page 1250005)
1010	Other or not stated	as-welded ERW round mechanical tube		170 to 300 MPa typical	310 to 450 MPa typical		MWAlloys: M1010 Round Mechanical Carbon Steel Tube (technical article, 2026-02-06)
1010	Other or not stated	DOM (drawn) round mechanical tube		max 275 MPa maximum	max 415 MPa maximum		MWAlloys: M1010 Round Mechanical Carbon Steel Tube (technical article, 2026-02-06)
1018	Hot rolled	hot rolled		240 MPa basis not stated	430 MPa basis not stated		MfgRobots: AISI 1018 Hot Rolled Steel, Properties and Applications
1018	Cold drawn	cold drawn		370 MPa basis not stated	440 MPa basis not stated		Carbon Steel Grade 1018 Data Sheet (Elgin), AISI 1018 Steel, cold drawn
1045	Hot rolled	hot rolled	under 250 mm	min 300 MPa minimum	570 to 700 MPa range as printed	170 to 210 HB	voestalpine High Performance Metals: AISI 1045 / 1.1191 / G10430 datasheet (Australia)
1045	Hot rolled	as rolled (hot rolled bar)	bar (page section C1045 Bar Products)	59,000 psi (407 MPa) typical	90,000 psi (621 MPa) typical		Metal Supermarkets: Hot Rolled Steel C1045 grade summary
1045	Cold drawn	cold drawn	under 16 mm	min 540 MPa minimum	min 690 MPa minimum		voestalpine High Performance Metals: AISI 1045 / 1.1191 / G10430 datasheet (Australia)
1045	Cold drawn	cold drawn	16 to 38 mm	min 510 MPa minimum	min 650 MPa minimum		voestalpine High Performance Metals: AISI 1045 / 1.1191 / G10430 datasheet (Australia)
1045	Cold drawn	cold drawn	38 to 63 mm	min 500 MPa minimum	min 640 MPa minimum		voestalpine High Performance Metals: AISI 1045 / 1.1191 / G10430 datasheet (Australia)
1045	Annealed	annealed	bar (page section C1045 Bar Products)	48,000 psi (331 MPa) typical	80,000 psi (552 MPa) typical		Metal Supermarkets: Hot Rolled Steel C1045 grade summary
1045	Normalised	normalized	bar (page section C1045 Bar Products)	58,000 psi (400 MPa) typical	87,000 psi (600 MPa) typical		Metal Supermarkets: Hot Rolled Steel C1045 grade summary
1070	Other or not stated	condition not stated		min 390 MPa minimum	640 to 700 MPa range as printed	192 to 212 HB	Gravity Cast Pvt. Ltd., data sheet: Material AISI 1070 (Standard Specification for Carbon Steel Compositions For Forging To Hot-Rolled Steel and Bar)
1070	Other or not stated	cold drawn, spheroidized annealed		not printed	640 MPa basis not stated	192 HB	eFunda: Properties of Carbon Steel AISI 1070
1070	Other or not stated	condition not stated		495 MPa basis not stated	not printed		eFunda: Properties of Carbon Steel AISI 1070
1215	Cold drawn	cold drawn	round bar, 19 to 38 mm	415 MPa basis not stated	540 MPa basis not stated	167 HB	AISI 1215 Steel, cold drawn, 19-38 mm round (datasheet printout, Budind)
1215	Other or not stated	cold finished (CF) bar, Alro C1215		60,200 psi (415 MPa) typical	78,300 psi (540 MPa) typical		C1215 Cold Finish Steel Bar (Alro Steel): composition, typical properties, typical uses
4130	Cold drawn	cold drawn tube, AMS 6371		70 ksi (483 MPa) typical	95 ksi (655 MPa) typical		Aircraft Materials: 4130 (AMS 6345 / AMS 6346 / AMS 6350) chrome-moly aircraft steel technical data sheet
4130	Annealed	annealed bar, AMS 6370 Not in the matrix: printed as max 29 HB; implausibly low for steel, probably a typo in the source, so left out of the matrix		not printed	not printed	max 29 HB	Aircraft Materials: 4130 (AMS 6345 / AMS 6346 / AMS 6350) chrome-moly aircraft steel technical data sheet
4130	Annealed	annealed sheet, AMS 6350		not printed	not printed	max 25 HRC	Aircraft Materials: 4130 (AMS 6345 / AMS 6346 / AMS 6350) chrome-moly aircraft steel technical data sheet
4130	Normalised	normalised at 870 C (1600 F), as the MatWeb record title states		435 MPa basis not stated	670 MPa basis not stated	197 HB	MatWeb: AISI 4130 Steel, normalized at 870 C (1600 F), datasheet printout
4130	Quenched and tempered	quenched and tempered: austenitize 1144 K (about 871 C) for 120 min, oil quench, temper 908 K (about 635 C) for 120 min, air cool row 4130 [8] of Table 1.1.3		635 MPa basis not stated	820 MPa basis not stated		Technical Reference on Hydrogen Compatibility of Materials: Low-Alloy Ferritic Steels, Tempered Fe-Cr-Mo Alloys (code 1211)
4130	Quenched and tempered	quenched and tempered: austenitize 1116 K, water quench, temper between 523 K and 813 K (about 250 C to 540 C) for 120 min lower of the two Sy levels printed for 4130 [6, 7]		1,050 MPa basis not stated	1,140 MPa basis not stated		Technical Reference on Hydrogen Compatibility of Materials: Low-Alloy Ferritic Steels, Tempered Fe-Cr-Mo Alloys (code 1211)
4130	Quenched and tempered	quenched and tempered: austenitize 1116 K, water quench, temper between 523 K and 813 K (about 250 C to 540 C) for 120 min high strength level; Section 3.2.2 calls 1330 MPa high strength		1,330 MPa basis not stated	1,600 MPa basis not stated		Technical Reference on Hydrogen Compatibility of Materials: Low-Alloy Ferritic Steels, Tempered Fe-Cr-Mo Alloys (code 1211)
4130	Quenched and tempered	hardened and tempered bar, AMS 6346; temper temperature not stated		100 ksi (689 MPa) typical	125 ksi (862 MPa) typical		Aircraft Materials: 4130 (AMS 6345 / AMS 6346 / AMS 6350) chrome-moly aircraft steel technical data sheet
4130	Quenched and tempered	round bar, usually supplied quenched and tempered, as the article states		not printed	not printed	18 to 22 HRC	Material Welding: Welding 4130 Steel: Complete Guidelines
4140	Normalised	normalised at 870 C, air cooled	25 mm (1 in.) round	655 MPa basis not stated	1,020 MPa basis not stated	302 HB	Alloy Steel Grade 4140 Fact Sheet (Elgin, mwcomponents.com), normalized at 870 C, 25 mm round
4140	Quenched and tempered	quenched and tempered: oil quench from 830 to 860 C, temper 540 to 680 C for at least 1 h, air cool	10 to 100 mm	min 740 MPa minimum	930 to 1,080 MPa range as printed	269 to 331 HB	voestalpine High Performance Metals: AISI 4140 / 1.7225 / G41400 datasheet
4140	Quenched and tempered	quenched and tempered: oil quench from 830 to 860 C, temper 540 to 680 C for at least 1 h, air cool	101 to 250 mm	min 665 MPa minimum	850 to 1,000 MPa range as printed		voestalpine High Performance Metals: AISI 4140 / 1.7225 / G41400 datasheet
4140	Quenched and tempered	hardened and tempered, supplied to condition T (the temper temperature is not stated)	50 mm	770 MPa typical	930 MPa typical	275 HB	Aircraft Alloy Steel AISI 4140 (AMS 6349 / AMS 6382) Technical Data Sheet (Aircraft Materials)
4140	Quenched and tempered	hardened and tempered, supplied to condition T (the temper temperature is not stated)	200 mm	570 MPa typical	850 MPa typical		Aircraft Alloy Steel AISI 4140 (AMS 6349 / AMS 6382) Technical Data Sheet (Aircraft Materials)
4140	Quenched and tempered	A 1116 K/60 min, water quench, T 755 K/120 min (A 843 C 1 h, water quench, temper 482 C 2 h); strength level high		1,235 MPa basis not stated	1,283 MPa basis not stated		Technical Reference on Hydrogen Compatibility of Materials: Low-Alloy Ferritic Steels, Tempered Fe-Cr-Mo Alloys (code 1211)
4140	Quenched and tempered	A 1116 K/60 min, water quench, T 755 K/120 min (A 843 C 1 h, water quench, temper 482 C 2 h); strength level high Not in the matrix: measured in 69 MPa hydrogen gas, an environment test		not printed	1,228 MPa basis not stated		Technical Reference on Hydrogen Compatibility of Materials: Low-Alloy Ferritic Steels, Tempered Fe-Cr-Mo Alloys (code 1211)
4140	Quenched and tempered	A 1116 K/60 min, oil quench, T 977 K/120 min, air cool (A 843 C 1 h, oil quench, temper 704 C 2 h, air cool); strength level low		642 MPa basis not stated	745 MPa basis not stated		Technical Reference on Hydrogen Compatibility of Materials: Low-Alloy Ferritic Steels, Tempered Fe-Cr-Mo Alloys (code 1211)
4340	Annealed	annealed at 810 C (as printed by eFunda)		not printed	744.6 MPa basis not stated	217 HB	eFunda: Properties of Alloy Steels, AISI 4340
4340	Quenched and tempered	quenched and tempered to condition T	limiting ruling section 150 mm	min 665 MPa minimum	850 to 1,000 MPa range as printed	248 to 302 HB	voestalpine High Performance Metals: AISI 4340 / 1.6565 / G43400 datasheet
4340	Quenched and tempered	quenched and tempered to condition U	limiting ruling section 100 mm	min 740 MPa minimum	930 to 1,080 MPa range as printed	269 to 331 HB	voestalpine High Performance Metals: AISI 4340 / 1.6565 / G43400 datasheet
4340	Quenched and tempered	quenched and tempered to condition V	limiting ruling section 63 mm	min 835 MPa minimum	1,000 to 1,150 MPa range as printed	293 to 352 HB	voestalpine High Performance Metals: AISI 4340 / 1.6565 / G43400 datasheet
4340	Quenched and tempered	quenched and tempered to condition W	limiting ruling section 30 mm	min 925 MPa minimum	1,080 to 1,230 MPa range as printed	311 to 375 HB	voestalpine High Performance Metals: AISI 4340 / 1.6565 / G43400 datasheet
4340	Quenched and tempered	quenched and tempered to condition X* (asterisked: typically ordered annealed for machining, then heat treated)	limiting ruling section 30 mm	min 1,005 MPa minimum	1,150 to 1,300 MPa range as printed	341 to 401 HB	voestalpine High Performance Metals: AISI 4340 / 1.6565 / G43400 datasheet
4340	Quenched and tempered	quenched and tempered to condition Y* (asterisked: typically ordered annealed for machining, then heat treated)	limiting ruling section 30 mm	min 1,080 MPa minimum	1,230 to 1,380 MPa range as printed	363 to 429 HB	voestalpine High Performance Metals: AISI 4340 / 1.6565 / G43400 datasheet
4340	Quenched and tempered	quenched and tempered to condition Z* (asterisked: typically ordered annealed for machining, then heat treated)	limiting ruling section 30 mm	min 1,125 MPa minimum	min 1,550 MPa minimum	min 444 HB	voestalpine High Performance Metals: AISI 4340 / 1.6565 / G43400 datasheet
4340	Quenched and tempered	quenched and tempered bars, typical range as the text states		not printed	not printed	24 to 38 HRC	Saky Steel: AISI 4340 Alloy Steel Flat Bar (stockist page)

Questions people ask

What is the tensile strength of 1045 steel?

Carbon steel 1045 (AISI/SAE 1045, UNS G10450) hot rolled bar has a tensile strength of 570 to 700 MPa per voestalpine, or 621 MPa typical as rolled per Metal Supermarkets. Normalised bar is 600 MPa and annealed bar 552 MPa, both typical per Metal Supermarkets. Cold drawn bar has a specified minimum of 690 MPa under 16 mm and 640 MPa at 38 to 63 mm per voestalpine. We found no quenched and tempered figure.

What is the yield strength of A36 steel?

ASTM A36 (UNS K02600) has a specified minimum yield strength of 250 MPa (36 ksi) for plates, bars and shapes under 8 in, per Wikipedia citing the Steel Construction Manual; SSAB prints 36 ksi (248 MPa) for plate. Plate over 8 in has a 220 MPa minimum per Wikipedia. Tensile strength is 400 to 550 MPa as a specified range. Both sources give minimums, not measured values, and neither states how A36 is made.

What is the yield strength of 4140 steel?

Alloy steel 4140 (AISI/SAE 4140, UNS G41400) quenched and tempered bar of 10 to 100 mm has a specified minimum yield strength of 740 MPa and a tensile strength of 930 to 1,080 MPa per voestalpine. For 101 to 250 mm the minimum is 665 MPa. Aircraft Materials prints typical yields of 770 MPa at 50 mm and 570 MPa at 200 mm. Normalised 25 mm round is 655 MPa per Elgin.

Is 4340 stronger than 4140?

Alloy steel 4340 (AISI/SAE 4340, UNS G43400) and alloy steel 4140 print identical figures at the same listed level: a specified minimum yield strength of 740 MPa and a tensile strength of 930 to 1,080 MPa, for 4340 at condition U and 4140 at 10 to 100 mm, per voestalpine. That datasheet calls 4340 stronger and lists conditions up to 1,125 MPa minimum yield. Our 4140 data has no datasheet figure at those levels, so the data cannot settle it.

Is 1045 stronger than 1018?

Carbon steel 1045 is stronger than carbon steel 1018 in every like-for-like pair in our data, but the sources use different bases. Hot rolled 1045 has a specified minimum yield strength of 300 MPa per voestalpine against 240 MPa for hot rolled 1018 per MfgRobots, which states no basis. Cold drawn 1045 under 16 mm has a 540 MPa minimum against 370 MPa for cold drawn 1018 per Elgin.

What is the difference between yield strength and tensile strength?

Yield strength is the stress at which steel starts to deform permanently, and tensile strength is the highest stress it carries before it breaks (general engineering knowledge, not in our data). Across the matrix, yield strength divided by tensile strength runs from 0.43 to 0.96. Hot rolled carbon steel 1045 is 0.43 to 0.53 on its specified minimum yield per voestalpine; cold drawn 1045 under 16 mm is 0.78.

How was this page made, and how do I cite it?

Every yield strength, tensile strength, hardness and elongation figure on this page was read from the nine Space Mushroom steel profiles when the page was built, and each is shown with its condition, basis and source. The profiles are AI-drafted and unreviewed by a named engineer. Data checked 1 November 2026.

How to cite: Space Mushroom, “Tensile and yield strength of carbon and alloy steel: 1018, 1045, 4130, 4140, 4340”, https://spacemushroom.com/articles/tensile-and-yield-strength-of-carbon-and-alloy-steel/, data checked 1 November 2026.

Each grade is a profile in the Space Mushroom database. The profiles are drafted by AI assistants from the cited pages, and a script checks that every value appears in the source it cites; each profile page lists its sources. Nothing in the matrix is typed by hand: the page reads every yield, tensile, hardness and elongation record from the nine profiles when it is built, files it under the condition the source named, and puts any record whose condition does not fit the five columns in "other or not stated". Where a source printed psi or ksi, the original is shown and the MPa value is converted with 1 ksi = 6.894757 MPa. Yield ÷ tensile is computed from records that come from the same source and condition. A named reviewer has not yet signed this article.

Last checked 1 November 2026. The CSV holds all 51 records, including the ones kept out of the matrix. Next review when a steel profile changes.

What are the yield and tensile strengths of A36, 1018, 1045, 4130, 4140 and 4340 steel?

ASTM A36 (UNS K02600)

Carbon steel 1018 (AISI/SAE 1018, UNS G10180)

Carbon steel 1045 (AISI/SAE 1045, UNS G10450)

Alloy steel 4130 (AISI/SAE 4130, UNS G41300)

Alloy steel 4140 (AISI/SAE 4140, UNS G41400)

Alloy steel 4340 (AISI/SAE 4340, UNS G43400)

How does the strength of each steel change with its condition?

1045 · Hot rolled 2 records

A36 · Other or not stated 3 records

1010 · Hot rolled 1 record

1010 · Cold drawn 1 record

1010 · Normalised 1 record

1010 · Other or not stated 3 records

1018 · Hot rolled 1 record

1018 · Cold drawn 1 record

1045 · Hot rolled 2 records

1045 · Cold drawn 3 records

1045 · Annealed 1 record

1045 · Normalised 1 record

1070 · Other or not stated 3 records

1215 · Cold drawn 1 record

1215 · Other or not stated 1 record

4130 · Cold drawn 1 record

4130 · Annealed 1 record

4130 · Normalised 1 record

4130 · Quenched and tempered 5 records

4140 · Normalised 1 record

4140 · Quenched and tempered 6 records

4340 · Annealed 1 record

4340 · Quenched and tempered 8 records

Which steels does this page cover, and what are their designations?

What does heat treatment change in steel, and what does it not?

What it changes

What it does not change

Is a steel strength figure a minimum or a typical value?

What does this mean in practice when choosing or ordering steel?

What do we not know about steel strength yet?

Questions people ask

What is the tensile strength of 1045 steel?

What is the yield strength of A36 steel?

What is the yield strength of 4140 steel?

Is 4340 stronger than 4140?

Is 1045 stronger than 1018?

What is the difference between yield strength and tensile strength?

Where can I find more data on these steels?

How was this page made, and how do I cite it?