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What does O stand for in bolts?
BOLTS? That’s Borders, Orientation, Legend, Title and Scale to you… One of the most useful skills when you’re embarking on your geographical career is mapping. (It also helps when you’re designing worlds for your next roleplaying game.)
What do the numbers mean for bolts?
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. Some metric nuts are also marked with a single-digit number to indicate the strength, and some may have the M and strength grade embossed on the flats of the hex.
What does P stand for on a bolt?
Common Fastener Related Abbreviations
| Abbreviation | Definition |
|---|---|
| P | Thread pitch, Also Phillips head |
| P/B | Plow bolt |
| PH | Phillips head |
| Phil. Or Ph Dr | Phillips drive |
What is the difference between Grade 5 and grade 8 bolts?
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. Grade 8 bolts have 6 evenly spaced radial lines on the head. Grade G is roughly equivalent to Grade 8.
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 |
What does 20 mean in bolt size?
20 threads per inch
US fasteners specify threads per inch (TPI), commonly called thread count, so 20 would represent 20 threads per inch. Metric fasteners instead specify a thread pitch which is the distance between the threads.
How do you measure a bolt with a tape measure?
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 does 8 mean on screws?
Their size is described as diameter, number of threads per inch (if used with a nut or in a threaded hole), and length in inches. In all cases, the larger the number, the larger the size. Consequently a #8 screw is larger than a #4 screw, just as a 3 inch bolt is larger than a 2 inch bolt.
What does 10.9 mean on a bolt?
For the 10.9 bolt, the 9 tells the user that the yield strength of the bolt is approximately 90% of the first number: 1,000 MPa. Thus, the 10.9 bolt has an approximate yield strength of 900 MPa (940 MPa by specification). Two other common symbols that are included on metric parts are the “S” and the 3 designations.