# What do bolt numbers mean?

Asked By: Danylo Drossel | Last Updated: 27th June, 2020
Category: business and finance mechanical and industrial engineering industry
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Diameter: the larger the number, the larger the fastener. Pitch: the larger the number, the more coarse the thread (the fewer the threads per unit of measure); coarse is the most common metric thread and is assumed when pitch isn't specified. Length: the larger the number, the longer the fastener.

Then, how do you read bolt numbers?

1. Read the first letter of the size. This the largest diameter: the measurement of the screw on the thread.
2. Read the second number. This is either the number of threads per unit of the distance between threads; also known as the "thread pitch".
3. Read the third number, generally the one following the "x."

One may also ask, is a #10 or #12 screw bigger? Machine screws are often found in sizes of: 0, 1, 2, 3, 4, 5, 6, 8, 10, 12, 14—the larger the number, the larger the screw.

People also ask, is a #12 screw the same as 1 4?

A #8 screw size is . 164 fraction of an inch. The diameters listed in the chart below are in fractions of an inch, so the #12 is just shy of 1/4 inch. A more detailed table with thread count can be found below, along with tap drill sizes.

What does m10x1 25 mean?

For example, an M10x1. 5 (coarse) thread has a 1.5mm pitch, while an M10x1. 25 (fine) thread has a 1.25mm pitch. For example, the thread "M10" automatically means a coarse pitch, while any added pitch callout, such as M10x1. 25, specifies a non-coarse pitch.

### What does m12x1 25 mean?

M12x1. 75 is the metric way of stating a screw thread. The M12 means the thread OD is 12mm, the 1.75 is the pitch of the thread. One turn of the screw moves the screw's position 1.75mm.

### What are the different types of bolts?

Types of bolts
• 3.1 Anchor bolt.
• 3.2 Carriage bolt.
• 3.3 Elevator bolt.
• 3.4 Flange bolt.
• 3.5 Hanger bolt.
• 3.6 Hexagon bolt/Tap bolt.
• 3.7 Lag bolt.
• 3.8 Machine bolt.

### What does m14x1 5 mean?

M14x1. 5 means the threaded part is 14mm diameter, 1.5 is the pitch of the thread ie the distance between thread peaks.

### What does m8 1.25 bolt 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.

### What does UNC 2a mean?

UN means UNified ( american standard ) C means Coarse ( standard big pitch versus Fine pitch ) 2A means the tolerance of the fabrication ( standard )

### How do bolt sizes work?

How do bolt sizes work? - Quora. There are usually three key numbers regarding bolt specifications, whether its metric or SAE. A typcial SAE fastener would be like 1/4–20 x 2 which specifies a 1/4″ diameter with 20 threads per inch and 2″ long. Diameters are fractions of an inch like 1/4″, 5/16, 3/8, 1/2 etc.

### Is 8 or 10 screw bigger?

Screws with a diameter smaller than 1/4" have a nominal size indicated by a number (e.g. #8 or #10). 1/4" and larger diameters are shown as inches. The diameter refers to the major diameter, or outside edge, of the threads.

### How big is a #10 screw?

US Machine Screw Diameters
Decimal Nearest Fractional
#10 0.19" 3/16"
#12 0.21" 7/32"
#14 0.24" 1/4"

### How big is a #6 screw?

Screws have three basic measurements: gauge, threads per inch, and shaft length in inches. So, you may also see a measurement like 6-32 x 1 1/2". This means it's a #6 diameter, with 32 threads per inch (almost double the normal thread count as a standard wood screw) and an inch and a half long.

### How can you tell screw size?

How to Determine Screw Size & Thread Count
1. Lay the screw down on a flat surface.
2. Place a steel rule down the axis of the screw.
3. Count the number of thread gaps within 1 inch of the screw.
4. Divide the count of thread gaps into the length.
5. Place the screw on a flat surface.
6. Lay a steel rule between two screw threads and measure across the diameter.

### What do the numbers mean on screw sizes?

What do the numbers - such as 8-32 mean on a machine screw? The first number is the diameter. The bigger the number the bigger the screw. The second number is the number of threads per inch.

### What is a #10 screw?

The term 10-32 comes from Unified and American Screw Threads for Bolts, Nuts, and Machine Screws standards published by ANSI B1. 1-1974. The number “10” is simply a size designator with no numerical meaning. The number “32” refers to 32 threads per inch.

### What are standard bolt sizes?

US Standard Thread Length for Bolts
Bolt Diameter Standard Thread Length (in.) *
Bolts 6 inches and shorter Bolts longer than 6 inches
1/4" 3/4" 1"
5/16" 7/8" 1-1/8"
3/8" 1" 1-1/4"

### Is 12mm the same as 3 8?

8mm = 5/16 inch. 9mm = almost 3/8 inch. 11mm = almost 7/16 inch. 12mm = almost 15/32 inch (= almost 1/2 inch)

### What is the most common screw size?

The most common size is #8 (approximately 5/32-inch in diameter), but the appropriate size of screw will depend on your individual project.

### What size is a #10 screw head?

Wood Screw Diameters