Can you use Grade 5 nuts on Grade 8 bolts?

Special markings on screw heads and nuts identify the fastener’s grade. Replace a graded fastener with same or higher grade (don’t replace a Grade 8 fastener with a Grade 5 or 2).

What is the difference between Grade 5 and 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. Grade 8 bolts have 6 evenly spaced radial lines on the head.

Should nuts and bolts be the same grade?

The rule is that the grade of the nut should always be the same as the bolt grade or one grade higher so: a grade 8.8 bolt should be fitted with a grade 8 or grade 9 nut. A grade 12.9 bolt should be fitted with a grade 12 or grade 14 nut.

Does a Grade 8 bolt need a grade 8 nut?

Grade 8 bolts have a tensile strength of 150,000 pounds per square inch. We recommend using grade 8 nuts, flat washers and high alloy lock washers with any grade 8 bolts / hex cap screws. The factor that makes a grade 8 bolt different from a lower grade bolt is its preload strength.

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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. … The Grade 5 bolt will therefore always fail first whether in tension or shear.

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 5 bolt hard?

Grade 5 Bolts and fasteners are made of medium strength carbon steel and are specified under the Society of Automotive Engineers (SAE). … with a minimum tensile strength of 120,000 psi in diameters through 1 in. and 105,000 psi for diameters over 1 in.

How much weight can a Grade 5 bolt hold?

Proof Load

Nom Bolt Size (in) Grade
2 5
5/16 2900 4450
3/8 4250 6600
7/16 5850 9050

Is grade A the same as Grade 5?

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.

How strong is a Grade 5 bolt?

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 and tempered 120,000
105,000
6 Radial Lines Grade 8 Medium carbon alloy steel, quenched and tempered 150,000
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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.

What does a Grade 5 bolt mean?

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 are Grade 5 nuts marked?

Grade 5 auts shall be marked with three circumferential dashes equally spaced 120° apart. Grade 8 nuts shall be marked with six circumferential dashes equally spaced 60° apart.

Can I use Grade 5 bolts for suspension?

Ideally you want OEM bolts for any suspension application. A Grade 8 will be strong but brittle. Any Grade 5 bolt wil be weak in this application.

Are there bolts stronger than Grade 8?

Grade 9 bolts are ideal for heavy-duty applications and are also often used in heavy machinery such as bulldozers. Not only are these bolts considerably stronger than they’re grade 8 counterparts, but they are also considerably more resistant to corrosive elements as they are made with yellow zinc chromate.

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.

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