Strong Match — 89.5% match
based on chemical composition and mechanical property overlap.
BS 970 EN9 (BS 970:1955) and SAE J403 1055 (SAE J403:2009) are both steel grades.
Both fall under the Carbon Steel category.
BS 970 EN9 is typically used for springs, chisels, punches, dies, while SAE J403 1055 is commonly used for chemistry-only grade; product scope as listed in the composition notes.
BS 970 EN9 is defined under British Standards (BS), originating from United Kingdom, while SAE J403 1055 is defined under SAE International, originating from United States.
As per chemical composition, BS 970 EN9 vs SAE J403 1055 is a 89.5% match.
Mechanical property data is not available for both grades, so this factor could not be scored.
Combined, this makes them a strong match overall at 89.5%.
Matched by chemical composition and mechanical properties, not a formal equivalence claim. Always verify against the applicable standard before substitution.
Mechanical Properties
Property
BS 970 EN9
SAE J403 1055
Tensile Strength
≥695 MPa (45 tons/sq in, converted)
Not specified
Yield Strength
≥355 MPa (23 tons/sq in, converted)
Not specified
Elongation
≥18%
Not specified
Hardness
201-255 HB
Not specified
Condition
Normalised, ruling section 4 in (lowest-strength condition of the standard)
Not specified
Typical Applications
BS 970 EN9
Springs, chisels, punches, dies
SAE J403 1055
Chemistry-only grade; product scope as listed in the composition notes
Key Differences
BS 970 EN9 specifies Si which is not specified for SAE J403 1055.
Can BS 970 EN9 Be Substituted With SAE J403 1055?
BS 970 EN9 and SAE J403 1055 overlap closely enough on chemistry and mechanical properties that SAE J403 1055 is often considered as a substitute for BS 970 EN9 in many applications. Always confirm the specific property range your application needs before substituting, and check with your supplier's mill certificate.
What is the difference between BS 970 EN9 and SAE J403 1055?
BS 970 EN9 specifies Si which is not specified for SAE J403 1055.
Can BS 970 EN9 be substituted with SAE J403 1055?
BS 970 EN9 and SAE J403 1055 overlap closely enough on chemistry and mechanical properties that SAE J403 1055 is often considered as a substitute for BS 970 EN9 in many applications. Always confirm the specific property range your application needs before substituting, and check with your supplier's mill certificate.