Standard commercial-grade shoulder screws come in diameters from ¼ to 2 in. and 6 to 24 mm. Precision-grade shoulder screws range from 3/32 to ½ in. and 6.5 to 12 mm in diameter.
How do you specify a shoulder screw?
To specify inch shoulder screws:
Example: 5/8″ x 2″ = a shoulder screw with a 5/8″ diameter shoulder, 2″ long. Thread size is one standard size smaller than the shoulder diameter and needn’t be specified, except for: A screw with a 1/2″ diameter shoulder has a 3/8 – 16 thread.
What is thread shoulder?
A shoulder screw, also called a shoulder bolt, has a shank with a larger diameter immediately below the head that “steps down” to a smaller diameter for the threaded length. The change in diameter provides a “shoulder,” which can be firmly tightened against the part to that which it is screwed.
What determines the size of a shoulder bolt?
Shoulder bolt size is determined by the diam- eter and length of the shoulder. NOTE: The smaller threaded section is the same length and diameter for all shoulder bolts with the same shoulder diameter.
Why do bolts have shoulders?
The shoulders give the screws their versatility by acting as shafts or dowels for rotating items such as bearings and bushings, axles for rolling parts, guides for sliding elements, and pivot points or mounting pins. Shoulder screws are often used in punch-and-die mechanisms or plastic-injection-mold sets.
Why do some bolts have a shoulder?
This is called the shoulder neck. It allows the head of the bolt to seat flush against its mating surface. Most manufacturers add a radius between the shoulder and the head of the bolt to reduce the notch effect. If the bolt has a radius, make sure that any washer or mating surface clears the protrusion.
What is the purpose of a washer on a bolt?
washer, machine component that is used in conjunction with a screw fastener such as a bolt and nut and that usually serves either to keep the screw from loosening or to distribute the load from the nut or bolt head over a larger area.
Do bolts allow rotation?
A tightened bolt is elastically elongated but strives to assume its original length, much like a spring. … However the bolt/nut is prevented from rotating by friction between the contact surfaces in the threads and under the bolt head/nut.
Why are washers called washers?
These are commonly used to spread the load on thin sheet metal, and are named after their use on automobile fenders. They can also be used to make a connection to a hole that has been enlarged by rust or wear. In the UK, the name originally comes from the size of the old British penny.
What is stripper bolt?
A stripper bolt is essentially a socket cap screw that is only partially threaded with a shoulder. Stripper bolts are measured by their diameter and length of the shoulder only; not including the head or thread. These bolts are often used on machinery to provide a smooth surface for bearings to ride on.
What is a bolt shank?
The shank is the threadless part of the bolt between the head and thread. There are two main ways of using the shank of the bolt. One is to make the shank increase the shearing capacity. … When bolts are being used as tension bolts, they should be more elastic than the joint members.
What is a hex bolt?
Hex bolts, or hex cap screws, are large bolts with a six-sided head (hexagonal!) used to fasten wood to wood, or metal to wood. … Wood screws have many different types of heads, but the most common are round heads and flat heads.
How are socket heads measured?
Socket screw measurement depends upon the type of screw you are using. Flat Socket Caps are measured by the overall length. Socket Head Caps and Button Head Caps are measured from under the head. Eye Bolts are measured from under the eye.
How do you measure a bolt socket?
How to Determine the Right Size Socket for a Nut
- Turn on the digital caliper and set it to read in inches, not millimeters. …
- Close the caliper jaws until each jaw rests on one flat side of the nut on opposite sides.
- Check the caliper display. …
- Turn on the digital caliper and set it to read in millimeters, not inches.
How do you measure screw sockets?
Measuring Bolts and Screws
Length is measured from the point at which the head sits flat with the surface, to the tip of the threads. Hex, pan, truss, button, socket cap, and round head screws are measured from right under the head to the end of the threads.