ksi to MPa

Table 1: ksi to MPa

Strength in ksi (thousand pounds-force per square inch) converted to megapascals. MPa rounded to 0.1.
Strength (ksi)	Strength (MPa)
5	34.5
10	68.9
15	103.4
20	137.9
25	172.4
30	206.8
40	275.8
50	344.7
60	413.7
70	482.6
80	551.6
90	620.5
100	689.5
110	758.4
120	827.4
130	896.3
140	965.3
150	1034.2
160	1103.2
170	1172.1
180	1241.1
190	1310.0
200	1379.0
220	1516.8
240	1654.7
260	1792.6
280	1930.5
300	2068.4

Source: factor from NIST Special Publication 811, 2008 Edition, Appendix B.8 (1 ksi = 6.894 757 MPa, rounded by NIST). Values computed on this page from the exact inch and pound-force definitions (6.894757293 MPa per ksi) and rounded to 0.1 MPa. Typical conversion, confirm with the supplier.

MPa to ksi

Table 2: MPa to ksi

Strength in MPa converted to ksi. ksi rounded to 0.1.
Strength (MPa)	Strength (ksi)
100	14.5
200	29.0
300	43.5
400	58.0
500	72.5
600	87.0
700	101.5
800	116.0
900	130.5
1000	145.0
1100	159.5
1200	174.0
1300	188.5
1400	203.1
1500	217.6
1600	232.1
1700	246.6
1800	261.1
2000	290.1

Source: same NIST SP 811 factor, divided: 1 MPa = 0.145 038 ksi. Computed on this page.

Datasheet values

Table 3: values from datasheets, converted

Values printed in ksi on two distributor datasheets, converted here. The datasheets do not print the MPa value.
Item and specification line	Property	Printed (ksi)	Converted (MPa)
Inconel 718 (UNS N07718), AMS 5662 minimum tensile, longitudinal, size 10 in and under	Tensile strength	185	1275.5
Inconel 718, same line	0.2% yield strength	150	1034.2
Inconel 718, AMS 5662 transverse or long-transverse lines	Tensile strength	180	1241.1
Ti-6Al-4V annealed sheet and plate, AMS 4911, over 0.1874 to 4.000 in	Tensile strength	130	896.3
Ti-6Al-4V annealed sheet and plate, AMS 4911, same size band	0.2% yield strength	120	827.4
Ti-6Al-4V bar, 1300 F anneal, typical range, low end	Tensile strength	138	951.5
Ti-6Al-4V bar, 1300 F anneal, typical range, high end	Tensile strength	155	1068.7

Sources: SSA Corp. "718 Nickel Alloy, Inconel 718, AMS 5662, UNS N07718" data sheet (minimum tensile properties at room temperature, precipitation heat treated per AMS 5662); Rolled Alloys "6AL4V" data sheet (AMS 4911 annealed sheet and plate; typical room-temperature bar range after a 1300 F anneal). Both opened October 2026. The specification text itself was not read; the figures are as the distributors print them. Directional only: use the current specification and your certificate.

Rounding check

Table 4: does a producer's MPa [ksi] pair match the factor?

Ultimate tensile strength of Inconel 718 at four cold-work levels, as printed in both units, with the conversion recomputed here.
Cold work (%)	Printed (MPa)	Printed (ksi)	ksi converted to MPa	MPa converted to ksi
0	655	95	655.0	95.00
37	1310	190	1310.0	190.00
50	1538	223	1537.5	223.07
92	2096	304	2096.0	304.00

Source: F.W. Metals, "INCONEL alloy 718" mechanical properties table, which prints "MPa [ksi]" pairs and states that values are typical and may not represent all diameters (opened October 2026). The page does not state a test temperature. Conversion recomputed on this page. The pairs agree within rounding: the largest gap in this table is under 0.5 MPa or 0.1 ksi, so a difference of that size is rounding and not a different strength.

Other units

Table 5: other stress units that turn up on certs

Multiply the value in the first column by the factor to get MPa.
From unit	To	Factor (MPa per unit)	Note
psi (lbf/in2)	MPa	0.006 894 757	NIST SP 811 lists 6.894 757 E+03 Pa per psi
ksi (kip/in2)	MPa	6.894 757	NIST SP 811 lists 6.894 757 E+06 Pa per ksi
kgf/mm2	MPa	9.806 65	Exact: NIST SP 811 defines 1 kgf as 9.806 65 N exactly
N/mm2	MPa	1	1 MPa is 1 000 000 N/m2, which is 1 N/mm2

Source: NIST Special Publication 811, 2008 Edition, Appendix B.8; N/mm2 identity follows from the definition of the pascal as one newton per square metre.

How to read it

Using the tables on a quote or a certificate

Check which unit the drawing and the certificate each use. The AMS lines in Table 3 are printed in ksi; metric certificates report MPa (equivalently N/mm2). If a drawing calls for a minimum in ksi and the certificate reports MPa, convert the certificate value and compare, instead of comparing the digits.

Decide the rounding rule before the lot ships. Table 3 shows that 185 ksi is 1275.5 MPa. A certificate that reports 1275 MPa sits 0.5 MPa under that converted figure, and whether that passes depends on which unit governs. State on the PO which unit governs the acceptance check, and whether a converted figure is rounded up, down or to the nearest whole number. Table 4 shows that a producer's own MPa and ksi pairs differ by a fraction of a unit after rounding, so a gap of that size is a rounding question to settle in writing.

Do not mix up what is being converted. The factor applies to stress: tensile strength, yield, proof stress, fatigue limits, modulus. It does not apply to hardness (HRC, HB, HV have their own conversion tables, which are approximate), to toughness in ksi root inch, or to the machinability numbers elsewhere on this site.

Keep the condition with the number. A tensile value is only meaningful for a stated alloy, condition and product form. Table 3 gives Inconel 718 at 185 ksi as a minimum for precipitation-heat-treated, longitudinal samples of size 10 in and under. Table 4 prints 876 MPa [127 ksi] for the same alloy at 0% cold work, and the page does not state the heat treatment. The two figures describe different material conditions, not different units.

On an RFQ, write the minimum in the unit the specification uses, add the converted value in brackets if your buyer or lab works in the other unit, and name the specification and revision. The engineer on the order reads the mill certificate against the PO; the certificate-handling steps are in material certificates and traceability, and the condition codes behind the numbers in 17-4 PH heat-treat conditions.

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