What does M8 mean on a bolt?

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.

Is M8 equal to 8mm?

M8 is not exactly 8mm but it is sufficient from a non-engineering point of view as long as the thread pitch is correct. Luckily, most commonly available metric bolts have the same pitch. Regarding tolerance for common uses it can also often be ignored.

What is M8 metric?

M stands for “Metric”. 8 is the bolt diameter, in millimetres. It usually comes with an additional number, such as 1.0, which is the pitch (distance between threads) in mm.

What does M stand for in bolt sizes?

Taking a closer look at this description, let’s explore its meaning: M = This designates the fastener is a metric size. 10 = The nominal diameter in millimeters. 1.0 = The thread pitch, or distance between threads, in millimeters. 20 = The fastener’s length, in millimeters.

What does 8.8 mean on a 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.

What size screw do I need for an 8mm hole?

But, to answer your Q – an M8 bolt will fit in an 8mm hole.

What do letters 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.

What does M8 1.25 mean?

For metric fasteners, you will see a M8 x 1.25 or an M8 x 1. For thread pitch, the distance between two points is the second number meaning the higher the number the fewer threads there are. This means the M8 x 1.25 is the coarse threading and the M8 x 1 is the fine thread.

Which is bigger M6 or M8?

The size of a metric screw or bolt is specified as diameter, pitch and length, in millimeters (millimeters is abbreviated “mm”).
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Table 3.
Metric Closest Inch
M6-1.0 1/4-28 (Larger)
M7-1.0 1/4-28 (Smaller)
M8-1.25 5/16-18 (Smaller)
M10-1.5 3/8-16 (Smaller)

What bolt is strongest?

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 does jh on bolt head mean?

What does HKT mean on a bolt?

The three-letter code is the manufacturer code (for example, HKT stands for Hau Kwang Enterprises) and the numbers (if metric) or radial lines (if SAE) refer to the bolts’ strength. If there are no numbers or lines present, assume the bolt is no better than a grade 2 (low strength).

Is there a Grade 9 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.

Is there 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.

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.
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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 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.

What is an L9 bolt?

The L-9 Hex Head Bolt is part of the L-9 Fastening System that is designed for high stress and severe service environments. This system consists of the L9 hex bolt, 2 L9 washers, L9 hex nut, and/or L9 hex locknut. … The L-9 system is made from AISI steel.

Is there a grade 12 bolt?

Do Grade 12 bolts exist? No SAE Grade 12 exists. On the metric side, there are no grades, only property classes. The highest strength property class is 12.9 which requires a tensile strength of approximately 1200 MPa and a yield strength of about 1080 MPa.

What are bolt grades?

The grade of a bolt determines the maximum amount of stress (tensile strength) that the bolt can handle. … The SAE marking system uses raised dashes on the bolt head to indicate strength. Metric Bolt Grades—Metric grades are set according to rules set by the ISO (International Standards Organization).

What is A325?

ASTM A325 Bolts

ASTM A325 structural bolts are heavy hex bolts made of medium carbon steel with a flat bearing surface, washer faced, and chamfered point. They are commonly used in structural steel joints in heavy construction and available in diameters ranging from 1/2” up to 1-1/2”.

What is a class 10 nut?

Class 10 nuts are metrics nuts with a steel grade equivalent to the SAE grade 8 classification. These are high-strength steels used in the automotive and structural industries.

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.