Grade 8 – Grade 8 bolts are made from medium carbon alloy steel. The bolts of this grade feature 6 radial lines. The nominal size of the grade 8 bolts can be from 1/4″ to 1 1/2″. The minimum yield strength of this grade bolt is 130,000 psi.
What class is a Grade 8 bolt?
|Metric Class 4||Similar to Grade 2.|
|Metric Class 8.8||Similar to Grade 5.|
|Metric Class 10.9||Similar to Grade 8.|
|Metric Class 12.9||The highest metric class for strength, it exceeds Grade 8.|
Are Automotive bolts Grade 8?
Most automotive hardware is Grade 5 rated and is identified by three radial lines on the head of the bolt. They are made from a medium carbon steel that is quenched and tempered. … Yield strength on Grade 8 bolts jumps to 130,000 PSI and tensile strength is 150,000 PSI.
How do you know if a bolt is grade 8?
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. A grade 8 bolt will have 6 radial lines on its head.
Is it Grade A or Grade 8 bolt?
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.
Is Grade 8 the strongest bolt?
Commercial-grade 8 bolts are the strongest option available. They’re made from medium carbon alloy steel and have markings that include six raised dashes. The psi of the bolt is 150,000, meaning that it can withstand great deals of pressure because of the way it was quenched and tempered.
What is meant by 8.8 grade bolt?
In the case of a 8.8 grade bolt the first figure signifies that the Tensile Strength is at least 800MPa. The second figure signifies that the fastener will begin to yield at 80% of the Ultimate Tensile Strength, i.e. at least 640MPa.
Will Grade 8 bolts rust?
Grade 8 Steel Bolts
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.
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.
What do 3 lines on a bolt head mean?
The markings can identify the standard to which the bolt was made. For instance, if a bolt head contains three radial lines, then it’s a Grade 5 bolt. If it contains five radial lines, then the bolt is Grade 8.
How can you tell the difference between Grade 8 and Grade 5 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 grade 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.
What is a Grade 10 bolt?
Class 10. This is a metric nut grading similar to the SAE grade 8 classification, which is used in conjunction with Class 10.9 bolts. This strength of nut is used in automotive, and structural industries, as well as in high temp applications.
What grade are black bolts?
The colour black, referred to the fact the steel used to make the bolts was not finished with any corrosion protection, although zinc plating is a common finish for durability. The grade 4.6, relates to the strength of the bolts.