What strength are B7 threads?
What strength are B7 threads?
Grade 8
| GRADE | ASTM A193 B7 (Chromium Molybdenum) | GRADE 8 (Heat Treated After Threading) |
|---|---|---|
| TENSILE STRENGTH | 125,000 PSI minimum 1,100°F tempering temp | 150,000 PSI minimum |
| YIELD STRENGTH | 105,000 PSI minimum minimum | 130,000 PSI minimum |
| ROCKWELL HARDNESS | C26-C32 | C33-C39 |
What is B7 hardness?
Grade B7 is a heat-treated chromium-molybdenum low-alloy steel with minimum tensile strength requirement of 125 ksi (860 Mpa), yield 105 ksi (720 Mpa), and maximum hardness of 35HRC.
Is B7 better than Grade 8?
The multiple heat treat process used to hardened Grade B7 bolts is designed to provide an excellent strength to toughness ratio for commercially available cap screws. Grade B7 provides higher strength than Grade 5 bolts with greater ductility than Grade 8.
Which is better B7 or B7M?
ASTM A193 Grade B7M studs are identical in chemistry to Grade B7, as they are quenched and tempered carbon steel to achieve a lower hardness. However, they have a lower tensile strength than B7 studs.
What nuts go with B7 bolts?
The nut material for Grade B7 bolts is typically ASTM A194 heavy hex nuts (2H nuts).
Why is the B7 threaded rod in high demand?
The versatile B7 threaded rod is in high demand because of its high strength, excellent heat resistance and resistance to corrosion. B7 is widely used in commercial plant applications and new construction projects for pipe and machinery installation and maintenance.
What is the hardness of a grade B7 fastener?
Grade B7 is a heat-treated chromium-molybdenum alloy steel with minimum tensile requirement of 100 ksi, yield of 75 ksi and maximum hardness of 35 HRC. ASTM A193 specification covers requirements for chemical composition, mechanical properties, hardness, heat-treatment, recommended nuts-washers for Grade B7 fasteners.
What is the grade of stainless steel threaded rod?
Class 8.8 and10.9 are classified as alloy steel quenched and tempered and are similar to U.S. Grades 8 and B7. Stainless steel threaded rod is also available in A2 and A4 stainless steel, which are the same as U.S. 304 and 316 stainless steels respectively.
What kind of fasteners are made from 4140 steel?
Alloy steel 4140 fasteners are formed using cold forging techniques, however big size fasteners or small quantities of 4140 bolts are produced by hot forging or directly machined from 4140 bar stock. All 4140 fasteners are marked with “BPF” mark followed by corresponding specification or grade symbol.