What does Grade 8 mean for a bolt?
What does Grade 8 mean for a bolt?
Grade 8 bolts are designated as a 150 ksi. This means its tensile strength or the resistance it has before it is subject to breaking under tension is equal to 150,000 lbs. per square inch. In comparison, a Grade 5 bolt is weaker as its tensile is 120 ksi, placing it at 120,000 lbs.
What is the strongest bolt grade?
Grade 9 structural bolts, also known as grade 9 hex cap screws, are one the strongest structural bolts that can be used today. While the typical grade 8 bolt has a tensile strength of 150,000 PSI, a grade 9 bolt has a tensile strength of 180,000PSI.
Is a 10.9 bolt stronger than Grade 8?
Class 10.9 is stronger than class 8.8. It is commonly found in high strength automotive applications. Class 10.9 is similar to grade 8.
What grade is a bolt with 6 marks?
Grade 8
Bolt Grade Markings and Strength Chart
| Head Marking | Grade and Material | Mechanical Properties |
|---|---|---|
| Min. Tensile Strength (psi) | ||
| 3 Radial Lines | Grade 5 Medium carbon steel, quenched and tempered | 120,000 |
| 105,000 | ||
| 6 Radial Lines | Grade 8 Medium carbon alloy steel, quenched and tempered | 150,000 |
What does 12.9 mean on a bolt?
Bolt Grade Markings and Strength Chart
| Grade and Material | Mechanical Properties |
|---|---|
| Min. Tensile Strength (psi) | |
| Class 8.8 Medium carbon steel, quenched and tempered | 830 |
| Class 10.9 Alloy steel, quenched and tempered | 1040 |
| Class 12.9 Alloy steel, quenched and tempered | 1220 |
Is Grade 8 or 12.9 stronger?
A head with no markings is Grade 2, one with 3 lines spaced 120 degrees is Grade 5, and 6 lines spaced at 60 degree intervals is Grade 8….Table 1.
| Grade/Class | Strength |
|---|---|
| Metric Class 10.9 | Similar to Grade 8. |
| Metric Class 12.9 | The highest metric class for strength, it exceeds Grade 8. |
How hard is a 10.9 bolt?
Used in automotive applications and for bolting large and forged parts, metric 10.9 bolts exhibit high tensile strength and good wear resistance. The yield strength of the bolts is 940 and the tensile strength is 1040 MPa.
Is a Grade 5 bolt stronger than Grade 8?
Grade 8 bolts have been hardened more than grade 5 bolts. Thus they are stronger and are used in demanding applications such as automotive suspensions.
What is the hardest grade bolt?
Grade 8 is the hardest, Grade 5 is medium, and Grade 2 is the softest. This is the most common grade of steel fastener and is the least expensive. Grade 2 bolts have no head marking, although sometimes a manufacturer’s mark is present. This grade of bolt is made from low or medium carbon steel.
What does 12.9 on a bolt mean?
The minimum ultimate tensile strength of the Grade 12.9 Metric Hex Head Bolts is about 1242 Mpa or 180,000 PSI, making them the highest grade of bolts produced.In fact, the Grade 12.9 Nuts is known for their high tensile strength.
How do I determine bolt grades?
Determine the grade of the bolt. The grade describes the grade of metal or the type of material used to manufacture the bolt. The grade of the bolt may be indicated by markings on the head. In the example, Grade 2 signifies a soft steel was used to make the bolt. Look at the head of the bolt. The shape of the head indicates what type of bolt it is.
What do the grades of bolts mean?
A. The grade of a bolt indicates the tensile strength of the steel. The higher the number the harder it is. The most common grades are 2, 5 and 8.
What is the strongest grade of bolt?
The strongest commercial-quality bolt is grade 8, marked by six raised dashes; its medium-carbon alloy steel has been quenched and tempered to achieve a tensile strength of 150,000 psi.
What are the strength of bolt grades?
Stainless commonly comes in grades 18.8 (304) or T316. Stainless steel bolts are rated for corrosion resistance. Bolt strength is rated in PSI (pounds per square inch). A stainless steel bolt has the same PSI rating as a grade 5 bolt (125,000 PSI). A grade 8 bolt has a stronger rating with a PSI of 150,000.