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You can usually figure out the grade, or strength, of a bolt by looking at the markings on its head. English bolts (U.S.S. or S.A.E) are categorized by grade, from grade 2 to grade 8, where the grade represents inch strength. The higher the grade, the stronger the bolt.
How is a Grade 5 bolt identified?
A grade 5 bolt is distinguished by 3 radial lines and promises tensile strengths between 105,000 and 120,000 psi. They are most commonly found in automotive applications. This sought-after grade 8 bolt can be distinguished by six raised dashes.
What does 8.8 on a bolt mean?
A property class (PC) is the metric equivalent of a grade in inch series terminology. So, in English, a PC 8.8 bolt is a bolt with a nominal tensile strength of 800 MPa and a nominal yield strength that is 80% of the bolt’s nominal tensile strength, or 640 MPa.
What grade bolt is the strongest?
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 do the markings on bolts 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.
Whats stronger Grade 8 or Grade 5 bolt?
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.
Is Grade 8 or 12.9 stronger?
A head with no markings is Grade 2, one with 3 lines spaced 120 degrees is Grade 5, and 6 lines spaced at 60 degree intervals is Grade 8.Table 1. Grade/Class Strength Metric Class 10.9 Similar to Grade 8. Metric Class 12.9 The highest metric class for strength, it exceeds Grade 8.
Is Grade 8 the strongest bolt?
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.
Does M8 mean 8mm?
Hole Sizes for Metric Bolts The defined diameter of metric bolts is actually slightly larger than the actual diameter of the bolt shaft. So an M8 bolt would have a shaft diameter that’s slightly under 8mm which means that the bolt should fit through an 8mm hole.
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.
Will Grade 5 bolts rust?
Many other grades exist but are used far less often. Grade 2, 5, and 8 are usually plated with a slightly blue-ish or yellow zinc coating, or are galvanized, to resist corrosion.
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.
What does 12.9 mean on a bolt?
High tensile Grade 12.9 Hex Bolts Grade 12.9 Hex Bolts are high strength bolts with 1100MPa minimum yield strength and 1220MPa minimum tensile strength.
What are Grade 8 bolts used for?
Grade 8 fasteners are considered hi-strength / high-tensile fasteners and are used in many highly industrial applications such as machinery, valves, pumps, vessels, motors, tractors, and even tanks… Although it may seem like a bolt is a bolt, there are significant differences in how each bolt is manufactured.
What grade is a bolt with 3 markings?
Three radial lines will indicate an SAE grade 5 fastener, while six radial lines will indicate an SAE grade 8 fastener.
Are stainless steel bolts stronger than Grade 5?
Stainless Steel Grades & Strength 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 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.
Will a Grade 5 bolt shear?
For example, an SAE grade 5 hex cap screw has a specified minimum tensile strength of 120,000 psi. Therefore, for design purposes, its shear strength could be reasonably assumed to be 70,000 psi.”Aug 7, 2007.
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.
What grade are cat bolts?
Cat Bolts. Cat® Bolts are built to exceed SAE Grade 8 standards and ISO 10.9 strength specifications for improved reusability and longer wear.
