How to read screw sizes. The bigger the number the stronger the bolt.
Thread Pitch Vs Threads Per Inch Tpi Albany County Fasteners
How to read standard bolt sizes. Second measure the pitch pitch is threads per unit. 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. Screws larger than a 10 have a diameter listed directly in inches. This the largest diameter. Diameter is in either inchesnot decimal or millimeter. All bolts whether standard or metric are sized according to diameter thread pitch and length.
The measurement of the screw on the thread. Heres what the description means. In the above example 12 inch is the shanks diameter. In metric fasteners an x is used to seperate each of the parts of the size. Unified screw diameters are. Often this is left off from the thread pitch.
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. The shank is the shaft like part of the bolt. The size of a metric screw or bolt is specified as diameter pitch and length in millimeters millimeters is abbreviated mm. Sometimes it is also left off of the other parts of the size. Measure the diameter of the shank.
Also known as the. For example a standard 12 162 bolt is 12 inch in diameter has 16 threads per inch and is 2 inches long. 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. It has a diameter of 0112 in 028 cm. Each part including the thread pitch is a measurement in millimeters so each may be followed by the abbreviation mm. For nuts size will appear as diameter and pitch.
The chart below shows metric bolt conversions and din numbers for fasteners. Read the second number. An m12 15 x 50 metric bolt is 12 mm in diameter has a thread pitch of 15 mm and is 25 mm long. Read the first letter of the size. Consider this size m8 10 x 20. For example on a 4 40 unc 3a x5 screw 4 represents the diameter.
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. Use calipers to obtain an accurate measure of the shanks diameter. This is either the number of threads per unit of the distance between threads. For example if the metric bolt was m14x15x25 it would have a length of 25 millimeters.
Gallery of How To Read Standard Bolt Sizes
