In addition, most metric bolts are identified bya number stamped on the bolt head, such as 4.6, 5.8or 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 thebolt.
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Regarding this, what does the mean on a bolt?
Sometimes there are lines on the bolt head. Thelines 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 acombination of letters and numbers to indicate thegrade.
Similarly, what do the numbers mean on metric screws? Besides using metric measurements, a metricbolt uses the distance between the threads rather than thethread pitch, used in American measurements, which is thenumber of threads per inch.
Also to know, what does 8.8 mean on a bolt head?
If you have ever looked a metric hex bolt youmight notice the markings 8.8, 10.9 or 12.9 this doesnot mean grade 8,10 or 12. The grade 8.8 refers tothe tensile strength which is generally 116,000 psi, grade 10.9 isgenerally 150,000 and grade 12.9 is generally 175,000psi.
What is the strongest bolt grade?
The strongest commercial-quality bolt isgrade 8, marked by six raised dashes; its medium-carbonalloy steel has been quenched and tempered to achieve a tensilestrength of 150,000 psi.
Related Question AnswersWhat are the markings on a bolt head?
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 andtempered | 120,000 |
| 105,000 | ||
| 6 Radial Lines | Grade 8 Medium carbon alloy steel, quenched and tempered | 150,000 |
What does M stand for in bolt sizes?
The M stands for 'Metric', as far as I cantell. There are or were several different systems for categorisingscrews; in the 1940s the International StandardsOrganisation issued a standard metric specification in anattempt to create a common system. In short: yes, an M5 screw willhave a diameter of 5mm.How can you tell if a bolt is grade 8?
The bolts that are not attracted to the magnetare Grade 8 bolts. If you do not have a magnet you can stillidentify Grade 8 bolts by brushing the head of thebolt using a wire brush and counting its radial lines. Thereare six radial lines on the heads of Grade 8bolts.How can you tell if a bolt is metric or standard?
For both metric and standard bolts, thehead size is the distance across the flats. For standardbolts, the head size is measured in inches or fractions of aninch. For metric bolts, head size is measured inmillimeters. However, metric bolt head size is measured inmillimeters.What does a triangle on a bolt head mean?
Re: Triangle sign on bolthead The Triangle means it is a Close Tolerancebolt .What does a325 mean?
ASTM A325 is an ASTM International standard forheavy hex structural bolts, titled Standard Specification forStructural Bolts, Steel, Heat Treated, 120/105 ksi Minimum TensileStrength. It defines mechanical properties for bolts that rangefrom 1⁄2 to 11⁄2 inches (13 to 38 mm) indiameter.What does Uhl mean on bolts?
Under Head LengthIs a 10.9 Bolt stronger than Grade 8?
Class 10.9 is stronger than class 8.8, andis commonly found in high strength automotive applications. Class10.9 is similar to grade 8. A low carbon steel forgeneral use.What does 12.9 on a bolt head mean?
The 12.9 is the Class head marking underASTM F568M standard for Bolts of a high grade (1220 MPa),being Alloy steel, quenched and tempered.Is 8.8 bolt high tensile?
Grade 8.8 high tensile steel is often referred toas the structural grade for bolts. It is the most commonform of high tensile material and is usually stocked inplain finish or zinc.How can you tell if a bolt is high tensile?
To identify this grade, look out for an '8.8'stamp or a set of three radial lines on the head of thebolt. Most often, customers looking for a high tensilebolt may just be looking for the 8.8 grade.What does grade of bolt mean?
The bolts of this grade feature 6 radiallines. The nominal size of the grade 8 bolts can befrom 1/4″ to 1 1/2″. The minimum yield strength of thisgrade bolt is 130,000 psi. A maximum of 120,000 psi oftensile force (proof load) can be applied to grade 8bolts.What does m10 mean?
M10 means a 10 millimeter outer diameter for thebolt or whatever piece it is; M12 means 12 millimeters. Thepart after the 'x' is the pitch -- how many mm a thread is wide. Tofigure out which you have, you can measure the existing part withcalipers and a thread gauge.What does m14x1 5 mean?
M14x1.5 means the threaded part is 14mmdiameter, 1.5 is the pitch of the thread ie the distance betweenthread peaks.What does m8 1.25 mean?
Designation detail : M symbol followed by nominaldiameter (for example, d = 8) and pitch (for example P =1.25) separated by the multiplication sign then followed bythe grade (for example: 6) and the thread gap (for example g). Fora screw or bolt: M8 x 1.25 6g. For a nut: M8 x1.25 6H.What is a #6 screw?
active oldest votes. 64. "6" is a #6-sizescrew. Screw gauges are a measure of the head sizeand shaft size, and are roughly linear but not quite a 1:1relationship (a #8 screw is a little less than twice thediameter of a #4 screw).Is m12 the same as 12mm?
Yes. M12 is a 12mm diameter thread. Youhave to be sure the thread pitch measured in threads per millimeter(1.5 here) is the same as what u need.How do you read a callout thread?
Steps- Look for a label with the callout printed on it.
- Use the first number to figure out the diameter of thethreads.
- Read the second number to find the number of threads perinch.
- Use the abbreviation to determine the thread standard if it islisted.
- Look for a number from 1 to 3 indicating the toleranceclass.
