Can this tool automatically generate a Jominy curve from a steel grade?

No. Heat, composition, grain size, and austenitizing condition all affect the curve. This tool analyzes only measured distance–hardness data entered by the user.

How is the 50% martensite hardness determined?

Within 0.10–0.70% C, it can be calculated from carbon content using the standard relationship, or a critical HRC confirmed by metallography or a company specification can be entered manually.

What does it mean when the curve crossing lies beyond the last measured point?

Hardness has not fallen to the criterion within the measured distance range. The last point cannot be treated as the true crossing; extend the measurement range or report only that the crossing is outside it.

Measured Jominy HardenabilityCurve Analyzer

Enter measured “distance from quenched end–HRC” data from an end-quench specimen to analyze the 50% martensite hardness crossing and interpolate at a specified distance. The page does not generate a curve from a steel grade.

Test object

Measured distance–hardness data from a standard Jominy end-quench specimen

Analysis

Linear interpolation, critical-HRC crossing, and non-monotonic anomaly warnings

Explicitly excluded

No fabricated curve from steel grade and no unsupported mapping to hardness across a complex workpiece section

Measured Data and Criterion

Carbon Content C (valid for 0.10–0.70%)

wt%

Custom Critical Hardness

HRC

Current Analysis Criterion

HRC

Measured Jominy Points

#	Distance from Quenched End, mm	Hardness HRC	Remove

Paste Two-Column Data

Comma, space, tab, or semicolon delimiters are accepted; importing replaces the current table.

Waiting for measured data. Enter at least three valid measured points to begin analysis.

Curve and Analysis Results

Enter at least three valid measured points
to plot the measured curve

Measured-point line Analysis criterion

Critical Hardness

HRC

50% M Crossing Distance

Interpolate Hardness at a Jominy Distance

Available after a valid curve is entered; no extrapolation beyond the measured range.

Valid Points

Measured Distance Range

Abnormal Rises

No crossing result yet. Enter a measured curve.

Open the Ideal Critical Diameter (DI) Calculator →

Measured-curve analysis · no material data generated

Test basis: ASTM A255 and ISO 642 specify the Jominy end-quench test method; this page only analyzes hardness data entered by the user.

50% M criterion: Carbon-content mode calculates only within 0.10–0.70% C; manual mode is for a critical HRC confirmed by metallography, a standard, or a company specification.

Interpolation limit: Linear interpolation is performed only between adjacent measured points; the last point is not extended outward.

Official ASTM A255 standard page · Official ISO 642:2024 standard page