Do you need Grade 8 nuts for Grade 8 bolts?

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.

Can you use Grade 5 nuts on Grade 8 bolts?

Yes, but nuts and bolts have very different failure mechanisms. … With Grade 5, A325 and metric 8.8 bolts, low strength nuts can be safely used unless the code prohibits them. With the stronger Grade 8, A490 and metric 10.9, high strength nuts have to be used and these bolts can strip the threads out of mild steel nuts.

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.

What is Grade 8 nuts and bolts?

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.

IT IS INTERESTING:  Does the hot go to the gold screw?

Is Grade 8 or 12.9 stronger?

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).

Table 1.

Grade/Class Strength
Metric Class 12.9 The highest metric class for strength, it exceeds Grade 8.

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 Grade 8 bolts hard?

A grade 8 bolt is the highest grade SAE bolt. Grade 8 bolts have a minimum tensile strength of 150,000 PSI.

Can Grade 8 bolts be welded?

Grade 8 fasteners are made of 4140 type alloy then heat treated. Excellent weld stock although the heat may anneal them some.

What grade bolt should I use?

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.

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.

IT IS INTERESTING:  What does a screw compressor do?

What is the breaking strength of a Grade 8 bolt?

Grade 8 bolts are designated as a 150 ksi. This means its tensile strength or the resistance it has before it is subject to breaking under tension is equal to 150,000 lbs. per square inch.

Are Grade 8 nuts marked?

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

What is a grade 10 nut?

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.

Is Grade 8 or 10.9 stronger?

Class 10.9 is stronger than class 8.8. It is commonly found in high strength automotive applications. Class 10.9 is similar to grade 8. A low carbon steel for general use.