The measurement of the screw on the thread. Sometimes it is also left off of the other parts of the size.
Bolts Aircraft Spec
How to read standard bolt sizes. Heres what the description means. This is either the number of threads per unit of the distance between threads. How to read screw sizes. Read the first letter of the size. All bolts whether standard or metric are sized according to diameter thread pitch and length. Often this is left off from the thread pitch.
The bigger the number the stronger the bolt. Look on the bolt head for the number denoting the strength of the bolt. To determine the size of a bolt first measure the diameter. The chart below shows metric bolt conversions and din numbers for fasteners. There is an exception thoughif pitch isnt specified the fastener is coarse threaded. Determine the length of the metric bolt by looking at the third number.
Read the second number. Second measure the pitch pitch is threads per unit. For nuts size will appear as diameter and pitch. An m12 15 x 50 metric bolt is 12 mm in diameter has a thread pitch of 15 mm and is 25 mm long. For example a standard 12 162 bolt is 12 inch in diameter has 16 threads per inch and is 2 inches long. Measure the diameter of the shank.
For example if the metric bolt was m14x15x25 it would have a length of 25 millimeters. Metric bolt conversion metric bolt conversion data for industrial boltsrods machine screws and small diameter fasteners from elgin fastener group includes metric to standard bolt conversions. This the largest diameter. Screws larger than a 10 have a diameter listed directly in inches. In the unified thread standard uts system manufacturers list the diameter size as a number between 0 and 10 with 0 being the smallest and 10 being the largest. Consider this size m8 10 x 20.
Use calipers to obtain an accurate measure of the shanks diameter. In the above example 12 inch is the shanks diameter. The size of a metric screw or bolt is specified as diameter pitch and length in millimeters millimeters is abbreviated mm. Diameter is in either inchesnot decimal or millimeter. Also known as the. The shank is the shaft like part of the bolt.
Each part including the thread pitch is a measurement in millimeters so each may be followed by the abbreviation mm. In metric fasteners an x is used to seperate each of the parts of the size. For example on a 4 40 unc 3a x5 screw 4 represents the diameter. It has a diameter of 0112 in 028 cm. Unified screw diameters are.
Gallery of How To Read Standard Bolt Sizes
