# What do bolt numbers mean?

**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?

**How to Read Screw Sizes**

- Read the first letter of the size. This the largest diameter: the measurement of the screw on the thread.
- Read the second number. This is either the number of threads per unit of the distance between threads; also known as the "thread pitch".
- 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.