How do you tell if a bolt is Grade 5 or 8?

How can you tell if a bolt is a Grade 5?

Grade 5 bolts are case hardened, meaning the bolt has been heated enough to hardened the outside of the bolt but not enough to harden the inside portion. Grade 5 bolts are identified by 3 evenly spaced radial lines on the head.

How many markings does a Grade 5 bolt have?

three markings
Hex heads with three markings are grade 5 fasteners. This grade is made from medium quality carbon steel. These are commonly used in automotive applications.

How much stronger is grade 8 than Grade 5?

Grade 8 Bolts

A grade 8 bolt is the highest grade SAE bolt. Grade 8 bolts have a minimum tensile strength of 150,000 PSI. As a comparison, the ASTM A325 bolt is roughly equivalent to the SAE grade 5. A grade 8 bolt would be one that meets ASTM A490 standards.

How do you tell the grade of a bolt?

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.

What is the marks on a Grade 5 metric bolt?

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.

What is harder Grade 5 or 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.

Are Grade 8 bolts or Grade 5 shear easier?

There exists an often quoted myth, that Grade 5 bolts are better in shear than Grade 8 since they will bend before breaking. Not true. Shear strength of alloy steel is approximately 60% of its ultimate tensile strength.

What is the difference between Grade 5 and Grade A bolts?

Because there are so many different grades and fasteners all look about the same, medium carbon and alloy steel strength grades are marked for identification.
…
Table 1.
Grade/Class Strength
Grade 2 Low strength.
Grade 2H Nuts Strength is similar to Grade 5. Use with ASTM A325 structural bolts.
Grade 5 Medium strength.

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.

What are Grade 5 bolts used for?

These bolts are generally used for non-critical joints and applications. 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.

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.

Are all Grade 8 bolts the same?

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. A maximum of 120,000 psi of tensile force (proof load) can be applied to grade 8 bolts.

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.

Is Grade 5 stronger than stainless steel?

The PSI rating of a stainless steel bolt is the same as that of a grade 5 bolt (125,000 PSI). With a PSI of 150,000, a grade 8 bolt has a higher rating.

What is the difference between Grade 2 and Grade 5 bolts?

Grade 2 is a standard hardware grade steel. This is the most common grade of steel fastener and is the least expensive. Except a possible manufacturer’s mark,Grade 2 bolts have no head marking. Grade 5 bolts are hardened to increase strength and are the most common bolts found in automotive applications.

Will Grade 8 yellow zinc bolts rust?

According to K-T Bolt Manufacturing Inc., Grade 8 bolts “are used in demanding applications such as automotive suspensions. 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.

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.

Do they make Grade 8 carriage bolts?

Grade 8 carriage bolts are stronger in comparison to other lower grade carriage bolts.

What is the strongest metal for bolts?

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.

What is the shear strength of a Grade 5 bolt?

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.”

What type of steel is used for grade 8 bolts?

medium carbon alloy steel
Grade 8 (SAE J429) is a medium carbon alloy steel with one of the highest tensile strengths available. With a minimum tensile strength of 150 ksi and a minimum yield of 130 ksi, Grade 8 has a higher tensile and yield strength than other steel grades such as Grade 5 and B7.

How many grades of bolts are there?

There are several grades of bolts but the three common grades for SAE are 2, 5 and 8. The common class (grades) for metric are 5.8, 8.8, 10.9 and 12.9. Each grade has a specific bolt strength. No matter the system used to grade the bolts, the higher number means the stronger the bolt.

What does JH mean on a bolt head?

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.