Head Markings

Specification Material Nominal Size in. Proof Load Stress ksi Tensile Strength Min Ksi Hardness Rockwell
Min Max
SAE J429 – Grade 1 Low or Medium Carbon Steel 1/4 thru 1 1/2 33 60 B70 B100
SAE J429 – Grade 2 1/4 thru 3/4 over 3/4 thru 1 1/2 55
33
74
60
B80
B70
B100
B100
ASTM A307 – Grade A 1/4 thru 4 60 B69 B100
ASTM A307 – Grade B 1/4 thru 4 60 min
100 max
B69 B95
SAE J429 – Grade 5
ASTM A449 – Type 1
Medium Carbon Steel, Quenched and Tempered 1/4 thru 1
over 1 thur 1 1/2
85
74
120
105
C25
C19
C34
C30
ASTM A449 – Type 1 over 1 1/2 thru 3 55 90 183 235
SAE J429 – Grade 5.1 Low or Medium Carbon Steel, Quenched and Tempered No. 6 thru 1/2 85 120 C25 C40
SAE J429 – Grade 5.2 Low Carbon Martensite Steel, Quenched and Tempered 1/4 thru 1 85 120 C26 C36
ASTM A449 – Type 2 C24 C34
F3125 ASTM A325 – Type 1 Medium Carbon Steel, Quenched and Tempered 1/2 thru  to 1 1/2 85 120 C24 C35
F3125 ASTM A325 – Type 2 Low Carbon Martensite Steel, Quenched and Tempered
F3125 ASTM A325 – Type 3 Atmospheric Corrosion Resistant Steel, Quenched and Tempered
ASTM A354 – Grade BC Medium Carbon Alloy Steel, Quenched and Tempered 1/4 thru 2 1/2
over 2 1/2 thru 4
105
95
125
115
C26
C22
C36
C33
SAE J429 – Grade 8 Medium Carbon Alloy Steel, Quenched and Tempered 1/4 thru 1 1/2 120 150 C33 C39
ASTM A354 – Grade BD 1/4 thru 1 1/2
over 2 1/2 thru 4
120
105
150
140
C33
C31
C39
C39
SAE J429 – Grade 8 .2 Low Carbon Martensite Steel, Quenched and Tempered 1/4 thru 1 120 150 C33 C39
F3125 ASTM A490 – Type 1 Medium Carbon Steel, Quenched and Tempered 1/2 thru 1 1/2 120 150 min
170 max
C33 C38
F3125 ASTM A490 – Type 2 Low Carbon Martensite Steel, Quenched and Tempered 1/2 thru 1 120 150 min
170 max
C33 C38
F3125 ASTM A490 – Type 3 Atmospheric Corrosion Resistant Steel, Quenched and Tempered 1/2 thru 1 1/2 120 150 min
170 max
C33 C38