For example, a bolt with a performance grade of 4.8 means: The nominal tensile strength of bolt material is 400 MPa. The yield-strength ratio of bolt material is 0.8.
What is class 4.8 steel?
medium carbon steel
Mechanical properties
| Grade, material & condition | Nominal thread diameter size range [mm] | Yield strength (min) [MPa] |
|---|---|---|
| Class 4.8 Low or medium carbon steel; fully or partially annealed | 1.6–16 | 340 |
| Class 5.8 Low or medium carbon steel; cold worked | 5–24 | 420 |
| Class 8.8 Medium carbon steel; quench and tempered | Under 16 (inc.) | 640 |
| 17–72 | 660 |
What do you mean by 4.6 grade of bolt?
The specification Class 4.6 Threaded Rod is a standard that covers fasteners manufactured from either Low carbon steel or medium carbon steel.The ultimate material strength of Grade 4.6 Threaded Rod is 40 Mpa while its yield strength or the proof stress is 60% that of the ultimate strength.
What’s the difference between 4.6 and 8.8 bolts?
Category 4.6/S refers to commercial bolts of Property Class 4.6 conforming to AS 1111.1 tightened using a standard wrench to a ‘snug-tight’ condition. Category 8.8/S refers to any bolt of Property Class 8.8, tightened using a standard wrench to a ‘snug- tight’ condition in the same way as for category 4.6/S.
What do the numbers on bolts mean?
Bolt Grade Markings
Each grade has a specific bolt strength. No matter the system used to grade the bolts, the higher number means the stronger the bolt. For most home and automotive applications, you won’t need anything more than a grade 8 bolt strength or metric class 10.9.
What grade is a 4.8 bolt?
They are commonly referred to as high strength bolts, and the others are commonly referred to as ordinary bolts. The grade label of bolt performance consists of two parts, which represent the nominal tensile strength and yield strength ratio of bolt material. 48 is 4.8.
What size is a 4.8 bolt?
Metric steel bolts, screws and studs – proof and tensile strength.
| Property Class | Size Range (mm) | Minimum Tensile Strength (106 Pa) |
|---|---|---|
| 4.8 | M1.6 – M16 | 420 |
| 5.8 | M5 – M24 | 520 |
| 8.8 | M1.6 – M36 | 830 |
| 9.8 | M1.6 – M16 | 900 |
Can you weld grade 4.6 bolts?
In general, fasteners, whether grade 4.6 or Grade 8.8, are not supplied as weldable items in their respective product standards and should not be welded.
Why do bolts have 8.8 on them?
8.8 is ISO 898–1 grading for Bolts and screws. It indicates a bolt/screw with tensile strength of minimum 800MPa and a yield strength of 80% of 800MPa = 640MPa. Depending on thickness these are either quenched and tempered or can also be used without Q&T provided they meet the hardness and tensile requirements.
What is the difference between 4.8 and 8.8 bolts?
8.8 nominal tensile strength 800N / mm2; nominal yield strength 640n / mm2. For example: grade 4.8, the tensile strength of the bolt is 400MPa; the yield strength is 400 * 8 / 10 = 320MPa.
What is the hardest grade bolt?
Grade 8
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 TB stand for in bolts?
TB and TF. The norm is TB – this means under loads the connections can slip such that the bolts bear against their 2 mm oversized hole. For applications where building movement is not acceptable, TF is used. And the bolt uses friction to prevent it from slipping to the edge of the hole.
How can you tell if a bolt is metric or standard?
How long is that bolt? Most bolts come in pretty uniform lengths; and this is a good way to determine if the bolt is metric or standard. Measure the bolt length (not including the cap), and see if it’s closer to a fraction of an inch, or a nice and round millimeter length that ends in 5 or 0.
Is 4.8 high tensile?
In a partially or fully annealed condition, the tensile strength of the Grade 4.8 Nuts is around 420 Mpa for low carbon steel and 500 Mpa for medium carbon steel, its core hardness in terms of Rockwell lies between B71 – 95.
Are Automotive bolts different?
Most common automotive fasteners are sized using two sets of number, the diameter and the thread count or pitch. For example, SAE bolts come in coarse and fine thread, which is referred to as thread count, such as ¼-20 and ¼-28, 28 being the fine-thread variant.
What is the strongest bolt?
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.
How many mm is M6?
6 mm
You can identify an M6 screw by measuring the diameter with a ruler. It’ll be 6 mm, or slightly more than 7/32 inches (0.228″).
What are standard bolt sizes?
US Standard Thread Length for Bolts
| Bolt Diameter | Standard Thread Length (in.) * | |
|---|---|---|
| Bolts 6 inches and shorter | Bolts longer than 6 inches | |
| 1/4″ | 3/4″ | 1″ |
| 5/16″ | 7/8″ | 1-1/8″ |
| 3/8″ | 1″ | 1-1/4″ |
Does welding a bolt weaken it?
Welding on a heat-treated bolt will weaken it because it would heat the bolt beyond its tempering point. When considering welding a bolt in any situation, you will need to know the material properties you are dealing with beforehand. When heat is applied to a pre-heated bolt, its strength will be altered.
Can you weld zinc nuts?
However, not every material is as safe to weld as the next. It is essential to understand the risks and safety procedures involved with every metal, as some, like zinc, can be dangerous if precautions aren’t taken. Can you weld zinc bolts? Yes, zinc bolts can be welded if you follow the proper safety guidelines.
Are nuts weldable?
As a general principle, welding should not be done on bolts or nuts. However, if essential, the composition of the bolt (and nuts if involved) must be carefully considered.” AISI takes the stance that welding to nuts and bolts should be avoided unless absolutely necessary.
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