How To Read Metric Bolt Sizes?

by | Last updated on January 24, 2024

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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

.

How are metric bolt sizes written?

Metric nuts and bolts are commonly referenced using ‘M’ sizes, for example:

M3, M8, M12

. But the size of a metric fastener is more accurately specified using diameter, pitch and length dimensions, in millimeters. For nuts the size dimensions used are simply diameter and pitch.

What size is a M10 bolt?

NOMINAL SIZE (D) BODY DIAMETER ACROSS THE FLATS m10

10.00


15.73
m12 12.00 17.73 m14 14.00 20.67 m16 16.00 23.67

What does M10x1 5 mean?

Metric thread callouts are fundamentally different because the thread pitch (distance between each thread, in mm) is specified instead of threads per inch or per mm. For example, an M10x1. 5 (coarse) thread has a

1.5mm pitch

, while an M10x1. 25 (fine) thread has a 1.25mm pitch.

How do you identify metric threads?

What does the 8.8 mean on a metric bolt?

The second number indicates one-tenth of the percentage of the part’s nominal yield strength compared to the part’s nominal tensile strength. 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

.

How can you tell if a bolt is metric or standard?

How long is that bolt? Most bolts come in pretty uniform lengths; and this is a good way to determine if the bolt is metric or standard. Measure the bolt length (not including the cap), and see if it’s closer to a fraction of an inch, or a nice and round millimeter length that ends in 5 or 0.

What does M12 mean?

The first half (M12), is

the size measurement (metric) taken across the outside diameter of the thread

(which in this case is 12mm). The second half is the thread pitch, which is the measurement of threads/inch (which in this case is 1.75).

How do I identify a bolt?

What is M12 in MM?

Tap size Basic major dia (mm) Basic major dia (inch) M8 x 1 8mm .3150 M10 x 1.5 10mm .3937 M10 x 1.25 10mm .3937 M12 x 1.75

12mm


.4724

What size bolt uses a 10mm socket?

The standard

6mm cap screw

has a 10mm head.

What does M8 mean?

M8 means

“Mate.”

The abbreviation M8 is an informal term of endearment for a friend. Most often used between men, M8 can also be a term of general acknowledgement.

What is m20 bolt?

Here’s what the description means… M = Metric thread designation. 8 = Nominal diameter, in millimeters. 1.0 = Pitch (distance from thread to thread), in millimeters. 20 =

Length, in millimeters

(see below)

What does #8 bolt mean?

Diameter is given as a one or two digit number for smaller sizes, and as a fraction for larger sizes. In all cases, the larger the number, the larger the size. Consequently a #8 screw is

larger than a #4 screw

, just as a 3 inch bolt is larger than a 2 inch bolt.

What is M12 in standard?

Metric Coarse Metric Fine BSF/BSW M8 x 1.25 M8 x 1 5/16′′ M10 x 1.5 M10 x 1.25 3/8′′ M12 x 1.75 M12 x 1.25

1/2′′
M14 x 2 M14 x 1.5 9/16′′

How do you know if a nut is metric?

If the nut is metric,

count the number of lines on the tape measure to find the measurement

. If you count 9 lines, the size is a 9-mm (millimeter) nut. If the nut is US standard, count the smallest lines on the tape measure in sixteenths. Add the sixteenths together to find the size.

Is Grade 8 the strongest bolt?


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.

What is the 8.8 on a bolt head?

The grade 8.8 refers to the

tensile strength which is generally 116,000 psi

, grade 10.9 is generally 150,000 and grade 12.9 is generally 175,000 psi.

What does TP mean on a bolt?

Abstract. In offshore windfarms there has recently been an increasing trend in the use of large diameter bolted connections for the connection between the

Transition Piece

(TP) and the Monopile (MP).

How do I know if my nut is SAE or metric?

Metric and SAE fasteners are measured differently and with different vocabulary. SAE nuts, bolts and screws are measured by their thread count, or TPI (threads per inch) and their length. Metric fasteners are measured by length and pitch, or the distance between threads.

How do you tell the difference between metric and standard sockets?

SAE sockets are sized in inches and fractions of inches. Metric and SAE wrenches have different systems of measurement.

Metric sockets and wrenches use the metric measurement system

. This is when millimeters are used to describe the size.

How do I know if my threads are metric or imperial?


Metric threads are measured by their pitch

. That is the distance from the crest of one thread to the crest of the next measured in millimetres. The pitch of a metric thread can be checked by direct measurement with a metric rule. Imperial threads have their pitch measured indirectly as a given number of teeth per inch.

Is an M12 bolt 12mm?


M12 bolts are a metric sized bolt with a 12mm thread diameter

. They have many applications but are often used to fasten metal to wood or to join different types of timber together. They are regarded as a heavy duty bolt and ideal for structural joints.

What M12x1 75?

M12x1. 75 is

the metric way to indicate a thread

. M12 means that the OD thread is 12mm, the 1.75 is the step of the thread.

What does M16 bolt mean?

Metric bolts are made fractionally under their stated size, for instance

an M16 bolt will have a shank diameter of typically 15.97mm

. This means that a 16mm bolt will fit through a 16mm hole but to allow for misalignment between parts it is common practice to drill bolt holes slightly larger.

David Evans
Author
David Evans
David is a seasoned automotive enthusiast. He is a graduate of Mechanical Engineering and has a passion for all things related to cars and vehicles. With his extensive knowledge of cars and other vehicles, David is an authority in the industry.