SAE J429 (Revised JAN1999), Table 1
Marking not verified to two sources. Low carbon boron martensitic steel, quenched and tempered.
| Size range | Proof | Yield min | Tensile min | Core hardness |
|---|---|---|---|---|
| 1/4 in through 1 in | 85 ksi (586 MPa) | 92 ksi (634 MPa) | 120 ksi (827 MPa) | Rockwell C26 to C36 |
Inch grades are published in ksi and metric classes in MPa. The other column on every row is a conversion at 1 ksi = 6.894757 MPa, rounded to the nearest whole unit - it is arithmetic on the published figure, not a second published figure.
Not described here. J429 prints the marking for this grade as a diagram rather than in words, and no two of the charts cross-checked for this page describe it. The strengths below are sourced; the marking is not, so it is left unstated.
Grade 5.2 carries the same strengths as Grade 5 but is made from a different steel, so the marking is what separates them. This site does not guess at a marking.
Count the radial lines and add two. That rule identifies exactly two grades - SAE Grade 5 with three lines and SAE Grade 8 with six - and it fails everywhere else. Grades 1, 2 and 4 carry no marking at all, so an unmarked head is not evidence of Grade 2; it is evidence of nothing, and unmarked hardware that meets no standard looks exactly the same. ASTM grades are stamped with the specification (A325, A490, BC, BD, 307A) rather than lines, and metric classes are stamped with the class number. Four marking systems share one bin.
Low carbon boron martensitic steel, quenched and tempered. Cold-headed high-volume parts where boron steel is cheaper to process.
Bolts and screws only, and only up to 1 in. There is no Grade 5.2 above 1 in.
Same published strengths as Grade 5 in this size range, different steel and a narrower hardness band.
Over 1/4 in through 1 in, SAE Grade 5.2 requires a minimum tensile strength of 120 ksi (827 MPa), a minimum yield of 92 ksi (634 MPa) and a proof load of 85 ksi (586 MPa).
Not described here. J429 prints the marking for this grade as a diagram rather than in words, and no two of the charts cross-checked for this page describe it. The strengths below are sourced; the marking is not, so it is left unstated.
Low carbon boron martensitic steel, quenched and tempered. Cold-headed high-volume parts where boron steel is cheaper to process.
Twenty-two grades and classes: the SAE J429 inch grades, five ASTM specifications and the ISO 898-1 property classes. It is not every grade in circulation. Stainless classes (ISO 3506 A2 and A4, ASTM F593), the ASTM A193 and A320 high and low temperature grades, ASTM F1554 anchor rod grades and SAE grades 3, 5.1 and 8.1 are not carried here.
Dimensions are as defined by SAE J429 (Revised JAN1999), Table 1. This site is an independent reference and is not affiliated with, endorsed by or approved by any standards body.
Every value on this page was cross-checked against 5 independent published sources:
Compare