ASTM A193 Grade B16 Specifications
ASTM A 193 GR. B16
Full thread Studs, Bolts.
Grade B16 is a heat-treated chromium- molybdenum-Vanadium alloy steel with minimum tensile requirement of asper Table below.
ASTM A193 specification covers requirements for chemical composition, mechanical properties, hardness, heat-treatment, recommended ASTM A194 Gr. 7 nuts.
Chemical Requirements @CrMoV
Elements |
Carbon |
Mn |
Phmax. |
Smax. |
Si |
Cr. |
Moly. |
Vanadium |
Al. |
Required% |
0.36-0.47 |
0.45-0.70 |
0.035 |
0.040 |
0.15-0.35 |
0.80-1.15 |
0.50-0.65 |
0.25-0.35 |
0.015 max, |
Product Variation |
0.02 |
0.03 |
0.005 over. |
0.005 over. |
0.02 |
0.05 |
0.03 |
0.03 |
Mechanical Requirements- @Inch Sizes [Metric Sizes]
Diameter, Metric |
MinimumTempering Temperature,Fe/ºC |
Tensile Strength, Min, ksi [MPa] |
Yield Strength, Min, 0.2%offset, ksi [MPa] |
Elongation In 4D,Min, % |
Reduction of Area, Min, % |
2.5″ / M64 and under |
1200 [650] |
125 [860] |
105 [725] |
18 |
50 |
Over 2.5″ to 4″M64 -M100 |
1200 [650] |
110 [760] |
95 [655] |
17 |
45 |
over 4″ to 8″M100-M200 |
1200 [650] |
100 [690] |
85 [585] |
16 |
45 |
P.N.: HARDNESS : 321 HB OR 35 HRC for All Range of Sizes.
S4. Hardness Testing of Grade B16
S4.1 For bolts or studs 21⁄2 in. [65 mm] or smaller, the hardness for Grade B16 shall be measured on or near the end of each bolt or stud using one of the methods prescribed in 10.2.1 for the Brinell or Rockwell C test. The hardness shall be in the range 253–319 HB or 25–34 HRC.
S12. Stress Rupture Testing of Grade B16
S12.1 One test shall be made for each heat treat lot. Testing shall be conducted using a combination test bar in accordance with Test Methods E292. Rupture shall occur in the smooth section of each test specimen. The test shall be conducted at 1100 °F [595 °C] and 20 ksi [140 MPa]. The test shall be continued until the sample ruptures. Rupture life shall be 25 h minimum. Testing is not required on material less than 1⁄2 in. [12 mm] thick.
S12.2 When a purchase order for fasteners invokes S12, the product marking supplied shall be “B16R.”
TABLE 4 Marking of Ferritic Steels
Grade |
Marking Symbol |
B5 |
B5 |
B6 |
B6 |
B6X |
B6X |
B7 |
B7 |
B7M |
B7M |
B16 |
B16 |
B16 + Supplement S12 |
B16R |