In addition, most metric bolts are identified by a number stamped on the bolt head, such as 4.6, 5.8 or 10.9. The number has nothing to do with the size, but does indicate the relative strength of the bolt. The higher the number, the stronger the bolt.
Also question is, what do the letters on the head of a bolt mean?
The lines on the head of a bolt indicate its grade. SAE J429 (Society of Automotive Engineers) bolts have radial lines, whereas ASTM (American Society for Testing and Materials) uses a combination of letters and numbers to indicate the grade.
Subsequently, question is, what do bolt numbers mean? Diameter: the larger the number, the larger the fastener. Pitch: the larger the number, the more coarse the thread (the fewer the threads per unit of measure); coarse is the most common metric thread and is assumed when pitch isn't specified. Length: the larger the number, the longer the fastener.
Regarding this, what does 8.8 on the head of a bolt mean?
If you have ever looked a metric hex bolt you might notice the markings 8.8, 10.9 or 12.9 this does not mean grade 8,10 or 12. The grade 8.8 refers to the tensile strength which is generally 116,000 psi, grade 10.9 is generally 150,000 and grade 12.9 is generally 175,000 psi.
What does M stand for in bolt sizes?
metric
What is a #10 screw?
The term 10-32 comes from Unified and American Screw Threads for Bolts, Nuts, and Machine Screws standards published by ANSI B1. 1-1974. The number “10” is simply a size designator with no numerical meaning. The number “32” refers to 32 threads per inch.What do 3 lines on a bolt head mean?
The higher the grade, the stronger the bolt. English bolts have radial lines on their head to identify the grade, or strength class. The number of lines on the bolt head is 2 less than the actual grade. So, for example, a grade 5 bolt will only have 3 radial lines on its head.How do you determine bolt nut size?
Stretch the tape measure to the other side of the inner threads of the nut. Count the lines to find the diameter of the threaded hole. Measure across the widest opening the threads make. This measurement will help you match the thread diameter of the nut with the thread diameter of the bolt.What are the different grades of bolts?
The most common grading system used for bolts in the U.S. is the SAE system, but you can find metric grading systems as well. There are several grades of bolts but the three common grades for SAE are 2, 5 and 8. The common class (grades) for metric are 5.8, 8.8, 10.9 and 12.9. Each grade has a specific bolt strength.How can you tell if a bolt is grade 8?
Look for Bolt Markings If you do not have a magnet you can still identify Grade 8 bolts by brushing the head of the bolt using a wire brush and counting its radial lines. There are six radial lines on the heads of Grade 8 bolts. Length is measured from under the head.Is 8.8 bolt high tensile?
Grade 8.8 high tensile steel is often referred to as the structural grade for bolts. It is the most common form of high tensile material and is usually stocked in plain finish or zinc. It can be plated in many other coatings.What does 12.9 on a bolt head mean?
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. ASTM F568M is an ASTM International standard for metric bolts, screws and studs that are used in general engineering applications.Is a 10.9 Bolt stronger than Grade 8?
Zinc plated for moderate corrosion resistance. A tempered medium carbon steel. Class 10.9 is stronger than class 8.8, and is commonly found in high strength automotive applications. Class 10.9 is similar to grade 8.What is tensile strength of a bolt?
What Is the Tensile Strength of Grade 8 Bolts? The tensile strength of a grade 8 bolt is 150,000 pounds per square inch. Tensile strength is the maximum load in tension (stretching) that a part can carry without breaking.What is the strongest bolt grade?
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.How much weight can a 3/8 bolt hold?
SAE Bolt Strength| Bolt Safe Working Loads (lbs) (Safe tensile load at 6,000 psi load) (Safe shear strength at 7500 psi load) | ||
|---|---|---|
| BoltDia(in) | NF Thread Grade 2 Iron Bolt | |
| 1/4 | 200 | 370 |
| 5/16 | 340 | 575 |
| 3/8 | 510 | 830 |
