What Grade Bolt Means?

How can you tell if stainless steel is 304?

Originally Answered: How do I check the grade of stainless steel 304 or 202 .


If you want to do spot check of SS, just take a random piece from the raw material and do a spark test.

Run a grinder on it, if the sparks are reddish orange, thin and don’t fly much it’s SS304..

Is there a grade 10 bolt?

There’s no such thing as a grade 10. There’s a 10.9 in metric. From the course I sat thru a couple months back grade 8 is the strongest bolt grade for SAE sizes.

Is there a grade 12 bolt?

Do Grade 12 bolts exist? No SAE Grade 12 exists. On the metric side, there are no grades, only property classes. The highest strength property class is 12.9 which requires a tensile strength of approximately 1200 MPa and a yield strength of about 1080 MPa.

What grade is a 12.9 bolt?

The 12.9 is the Class head marking under ASTM F568M standard for Bolts of a high grade (1220 MPa), being Alloy steel, quenched and tempered.

Are stainless bolts stronger than Grade 8?

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.

Is a 10.9 Bolt stronger than Grade 8?

A tempered medium carbon steel. 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 is the meaning of 8.8 grade in a bolt?

8.8- This type of grade is often referred to as the structural grade for bolts. … When a bolt has a grading of S, it means that it can withstand a stress of 45 to 49.9 metric tonnes per 6.45 cm². This grading, which is typically stamped on the head of the bolt, has the same tensile strength as a grade 8.8 bolt.

Is 304 or 316 stainless better?

The most basic difference between grade 304 and grade 316 stainless steels is that 316 tends to have more nickel and a bit of molybdenum in the mix. … Though the stainless steel 304 alloy has a higher melting point, grade 316 has a better resistance to chemicals and chlorides (like salt) than grade 304 stainless steel.

How can I tell if my stainless steel is 304 or 316?

Try the magnet test. If the magnet sticks it cannot be 316 and might be 304. If the magnet doesn’t stick it could be either 316 or cold worked 304, so heat the piece to about 800 °C, let air-cool and try again with magnet. If it sticks now its 304 SST.

What grade is a bolt with 6 marks?

Bolt Grade Markings and Strength ChartHead MarkingGrade and MaterialMechanical PropertiesProof Load (psi)3 Radial LinesGrade 5 Medium carbon steel, quenched and tempered74,0006 Radial LinesGrade 8 Medium carbon alloy steel, quenched and tempered120,000Grade A325 Carbon or alloy steel with or without boron85,00018 more rows

What is the difference between 8.8 and 12.9 grade bolts?

The mechanical difference between the 12.9 and 8.8 is yield strength (roughly 90% of 1200 MPa vs 80% of 800 MPa). That means the 12.9 can be stretched further (i.e. torqued to some higher value) before it yields, which of course increases the clamp force.

What is the difference between a 10.9 and 12.9 Bolt?

12.9 grade steel has 120% of the tensile strength of 10.9 grade steel. The “12” prefix indicates a tensile strength of X100 N/mm^2 and the “9” suffix indicates a multiplier. Both 12.9 and 10.9 have the same multiplier, so the comparison is straightforward: 12 to 10.

Will Grade 8 bolts rust?

Grade 8 bolts have 6 evenly spaced radial lines on the head.” Unlike stainless steel, which is highly resistant to corrosion, steel, however reinforced, will oxidize over time and rust. Grade 8 bolts that are not galvanized or plated with yellow zinc, however, are cheaper.

What is the hardest bolt you can buy?

The world’s strongest bolts are stainless. BUMAX® Ultra has proven itself as the world’s strongest bolt – in various highly-demanding critical fastener applications around the world where standard fasteners are simply inadequate.

How can you tell a Grade 8 nut?

Grade 5 auts shall be marked with three circumferential dashes equally spaced 120° apart. Grade 8 nuts shall be marked with six circumferential dashes equally spaced 60° apart.

What grade Bolt is the strongest?

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.

Is a 12.9 Bolt stronger than Grade 8?

Property class (often just “class”) specifies metric fasteners. Special markings on screw heads and nuts identify the fastener’s grade….Table 1.Grade/ClassStrengthMetric Class 8.8Similar to Grade 5.Metric Class 10.9Similar to Grade 8.Metric Class 12.9The highest metric class for strength, it exceeds Grade 8.11 more rows

What is the best grade of stainless steel?

Type 304: The best-known grade is Type 304, also known as 18/8 and 18/10 for its composition of 18% chromium and 8%/10% nickel, respectively. Type 316: The second most common austenitic stainless steel is Type 316.

What does 12.9 mean on a bolt?

12.9 grade steel means that a component manufactured form this grade of steel has 12X100 N/mm^2 tensile strength and 9 is a multiplier means 90% of 1200 = 1080 N/mm^2 is the yield strength of the grade. Similarly we also have grade 8.8 , 10.9 , 6.8 also.

How strong is a grade 12.9 bolt?

The minimum tensile strength of a 12.9 bolt is 1220 MPa. Therefore, the approximate shear strength of a 12.9 bolt is 732 MPa. The minimum yield strength of a bolt is the pressures needed to stretch the metal of the bolt. A 12.9 bolt has a minimum yield strength of 1100 MPa.