# How are bolt sizes measured?

## How are bolt sizes measured?

How to Measure the Size of a Bolt

1. Step 1: Measure the shank’s diameter. The shaft of the bolt is called the shank, and its diameter is the first dimension used to describe a bolt size.
2. Step 2: Determine the thread pitch.
3. Step 3: Measure the length of the shank.
4. Step 6: Measure the length of the threaded portion of the bolt.

## How do you measure the diameter of a bolt head?

To measure the diameter of screws and bolts, you measure the distance from the outer thread on one side to the outer thread on the other side. This is called the major diameter and will usually be the proper size of the bolt.

How do you read a bolt diameter?

Whether metric or standard, all bolts are sized by diameter, thread pitch, and length—in that order. So, for example, an SAE 1/2-16 x 2 bolt is ½” in diameter, has 16 threads per inch, and is 2″ long. An M12-1.5 x 50 metric bolt is 12mm in diameter, has a thread pitch of 1.5mm, and is 50mm long.

What tool is used to measure the diameter of a bolt?

Measuring the Diameter. Use a bolt gauge to find the diameter quickly and easily. A bolt gauge is divided into standard and metric sections.

### 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
3/8″ 1″ 1-1/4″
7/16″ 1-1/8″ 1-3/8″
1/2″ 1-1/4″ 1-1/2″

### What are standard metric bolt sizes?

Metric clearance and tapping drill hole sizes.

Size Clearance Hole mm Tapping Drill (std Pitch)
M5 5.5 4.2 mm
M6 6.5 5.0 mm
M8 9 6.75 mm
M10 11 8.5 mm

What do bolt sizes mean?

The size of a metric bolt is specified using pitch, diameter, and length in millimeters. For example, in M8-1.0*20, the “M” means the Metric thread designation, the digit 8 refers to the Nominal diameter (in millimeters), 1.0 refers to the pitch, and 20 refers to the length.

What do bolt size numbers mean?

## What is M8 bolt size?

M8 is the designation for a metric (M) sized bolt or screw that is 8mm (8) in diameter. This is roughly equivalent to a 5/16 bolt or screw.

What are the most common metric bolt sizes?

The most common were the 12mm and 10mm, followed by the 15, 17 and 19mm.

What are the different sizes of bolts?

Hex Bolt, Lag Bolt, Square Bolt and Heavy Hex Bolt

US Bolts
Bolt Diameter (in) Head and Wrench Size (in)
1/2 3/4 7/8
9/16 13/16
5/8 15/16 1 1/16

### What are the dimensions of a steel bolt?

Body Diameter – There may be a reasonable swell or fin under the head or die seam on the body not to exceed the basic bolt diameter by the following: 0.030″ for sizes up to 1/2″. 0.050″ for sizes 5/8″ and 3/4″.

### Where can I get a measurement for a bolt?

Figuring out the size of a bolt seems like a simple enough task until you try to match your bolt with a sea of options at the hardware store. In order to get accurate measurements, you’ll need a bolt gauge, which you can purchase from your local hardware or auto parts store.

How big is a nut compared to a bolt?

But neither the external threads of the bolt nor the internal threads of the nut are exactly .500 in diameter. In fact, the bolt diameter is a little smaller and the nut diameter a little larger.

How to measure the pitch of a bolt?

Method 2 of 3: Finding the Thread Pitch 1 Turn your bolt gauge over to find the thread gauge. 2 Rub the bolt on different sized thread gauges. Run the threads of the bolt along the thread gauge of the appropriate type (standard or metric). 3 Stop when the thread gauge grabs the threads of the bolt. 4 Make a note of the thread pitch. …