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AISI 4340 vs SAE J404 8640

Close Alternative — 70.4% match based on chemical composition and mechanical property overlap.

AISI 4340 and SAE J404 8640 (SAE J404:2009) are both steel grades. Both fall under the Alloy Steel category. AISI 4340 is typically used for aircraft parts, heavy duty gears, crankshafts, high tensile bolts, while SAE J404 8640 is commonly used for chemistry-only alloy steel grade; see the composition notes for product scope. AISI 4340 is defined under AISI, originating from United States, while SAE J404 8640 is defined under SAE International, originating from United States.

As per chemical composition, AISI 4340 vs SAE J404 8640 is a 70.4% match. Mechanical property data is not available for both grades, so this factor could not be scored. Combined, this makes them a close alternative overall at 70.4%.

Frequently Compared With AISI 4340:
NF A35-565 100C6 UNI 11234 100Cr6 GB/T 3077 12Cr2Ni4A GOST 4543 12HN3A IS 1570 (Part 4) 103Cr4 IS 1570 (Part 4) 105Cr5 IS 4367 07Cr4Mo6 IS 1570 (Part 4) 103Cr6 IS 1570 (Part 4) 10Cr20Mo6 IS 1570 (Part 7) 10Cr36Mo10H IS 1570 (Part 4) 07Cr4Mo6 IS 4367 10Cr9Mo10
Match Breakdown
CHEMISTRY MATCH
70.4%
MECHANICAL MATCH
No shared data
OVERALL
70.4%
Specifications
Property AISI 4340 SAE J404 8640
Standard AISI SAE J404:2009
Category Alloy Steel Alloy Steel
C (%) 0.38–0.43 0.38-0.43
Mn (%) 0.60–0.80 0.75-1.00
Cr (%) 0.70–0.90 0.40-0.60
Mo (%) 0.20–0.30 0.15-0.25
Ni (%) 1.65–2.00 0.40-0.70
Si (%) 0.15–0.35 0.15-0.35
P (%) Not specified <=0.030
S (%) Not specified <=0.040
Matched by chemical composition and mechanical properties, not a formal equivalence claim. Always verify against the applicable standard before substitution.
Mechanical Properties
Property AISI 4340 SAE J404 8640
Condition Quenched & Tempered Not specified
Tensile Strength 1000–1200 MPa Not specified
Yield Strength ≥830 MPa Not specified
Elongation ≥12% Not specified
Hardness 285–341 HB Not specified
Typical Applications
AISI 4340
Aircraft parts, heavy duty gears, crankshafts, high tensile bolts
SAE J404 8640
Chemistry-only alloy steel grade; see the composition notes for product scope
Key Differences
Can AISI 4340 Be Substituted With SAE J404 8640?
AISI 4340 and SAE J404 8640 are a close alternative rather than a direct substitute. Some properties overlap well, but check the specific chemistry and mechanical rows above against your application's requirements before treating them as interchangeable.
Forms & Sizes Available on M-EX
AISI 4340
Round Bar → (3 listings)
Diameter: 50–50 mm (1.97–1.97 in)
Length: 5900–6800 mm (232.28–267.72 in)
SAE J404 8640
No active listings currently.
On M-EX Right Now
AISI 4340
3 active listings and RFQs →
SAE J404 8640
0 active listings and RFQs →
Frequently Asked Questions
What is the difference between AISI 4340 and SAE J404 8640?
SAE J404 8640 specifies P, S which are not specified for AISI 4340.
Can AISI 4340 be substituted with SAE J404 8640?
AISI 4340 and SAE J404 8640 are a close alternative rather than a direct substitute. Some properties overlap well, but check the specific chemistry and mechanical rows above against your application's requirements before treating them as interchangeable.