Information On 'Short Bolting'

 

Designing and manufacturing different items will usually require extensive preparation as you plan out what materials you will need. However, while in professional manufacturing the nuts and bolts needed are always accounted for, in-home projects those same items are often the last thing in people’s lives. As a result, people will usually just try and utilize whatever nuts and bolts they have available in their homes. While this might work in some cases it is not always the best idea.

 

The easiest way to avoid short bolting is to measure ahead of time. When measuring the length of the bolt you will need you should take into account both the width of the material you will want to screw the bolt through, as well as the size of the nut you are using. From there make sure to consider that you will want a couple of the thread pitches to extend beyond the nut. This will provide greater stability.
Apart from deciding which bolts to use, you will also need to choose what types of nuts you would like to employ for this project. The length of the bolds you are choosing to use for your project could affect the stability and reliability of the project. Therefore, this is not a case of just choosing a shorter nut to accommodate a shorter bolt, as the strength of that connection might still be subpar and thus, lead to problems in your design. Instead, you should carefully consider the strength you need your fasteners to hold in order to determine what the best possible size is.
Pre-measuring and buying the materials that you need is the key to avoiding short bolting. If you just choose to make do with whatever you find you will be far more likely to be disappointed as the nut will protrude more than the bolt.

 

In most situations, short bolting is a problem and it should be avoided where possible. This is because in order for the full strength of the nut to be realized a few of the nut’s threads will need to protrude. It is also important to note that if the nut threads are not protruding it becomes a lot more probable that thread stripping might occur.
It is also important to remember that not having the nut protrude means that there is less connection between the bolt and the nut. Thus, it is much more likely that in the case of loosening the bolt could go completely loose.

It is not common practice for short bolting to occur. What is in fact common practice is the exact opposite where two thread pitches or more protrude from the bolt. This is particularly important because the first few threads of any nut are usually only partially formed. As such they don’t always have the same width as the rest of the nut, which could lead to further problems in the stability of the construction.

If as part of a project shorter nuts are used but the two thread pitches required are protruding then the likelihood of thread stripping is not going to increase. However, if that is not the case and the use of shorter nuts means that the bolt is the one protruding then you will find that the chances of thread stripping are increased. This in part is because the bolt which is regularly made to withstand the tensile fracture before the nut or bolt thread start to strip is now having to carry the intense load without being at its full strength. As such, thread stripping is more likely in cases of short bolting.

When choosing fasteners, nuts, and bolts for your project one of the most important things to ensure is that both of them have a matched grade level. It is also important that you choose nuts of the correct length so as to avoid short bolting where possible. To find high-quality nuts and bolts you can visit AYA FASTENERS for nuts that will match both your grade and length needs.

Hex Bolts

Hex Nuts

Wood Screws

 

To be safe you should always make sure that there is a minimum of two thread pitches that extend beyond the surface of the nut. Having more than two is not a problem usually, as the connection you have created will still be able to operate at its full strength. As thread stripping starts from the first thread, you should avoid having less than two thread pitches protruding since if the first one has started stripping the damage will quickly affect the construction quality of your design.

 

Thread stripping is a term used to refer to the shear failure of an internal or external thread caused by having a higher strength applied on the threaded material than the strength the material can withstand. In cases of thread, stripping replacement is required, this alone is enough reason to try and avoid thread stripping as much as possible.

 

More importantly, thread stripping leads to unreliable designs which in time could fail. As thread stripping is a relatively gradual process, the problems that could be caused by thread stripping are not always noticed immediately which is why thread stripping might go unnoticed at the start.

 

As thread stripping starts with the first engaged thread, the reality is that the deformations are gradual. More importantly though, if that first thread is not protruding due to bolt shortening, then the connection will immediately be affected by thread stripping. As the connection created by the bolt and the nut is not going to be at its full strength due to the short bolting the reality is that the heavy load will quickly start affecting the already threading nut. As the strength of a nut or bolt cannot be viewed in isolation and are in fact in a fully interdependent relationship, problems such as short bolting will have a direct effect on their strength, and thus thread stripping will become more common, and is without considering what effects thread bending, nut dilation or bell mouthing might cause.

Your bolt length tolerance will usually be disclosed in a table available on the website of the manufacturer you are buying your bolts from. In general, length bolts are going to have a higher tolerance than shorter bolts. However, that does not mean that there are necessarily any benefits to using a bolt that is longer than required. This is because the maximum strength of a steel bolt and nut is achieved when the length of engagement between the two is the same as the diameter of the bolt. This is why it is also common for people to shorten the bolts that they are using if too much of the bolt is protruding for no reason.

                                                                                                                                                                                                                                                                                                   Full Thread Hex Bolt 

Conclusion
When it comes to choosing the right bolts and nuts for each project it is all about understanding the length of bolts you need and the strength that you will require the connection to hold. Avoiding short bolting is not only important because of strength though, it is important because of the damage that you might cause in your design by choosing to work with the wrong tools. Short bolting will increase the likelihood of thread stripping while making it more likely that your fasteners malfunction. This is why early preparation can be the key to using nuts and bolts. By measuring ahead of time and choosing the right sizes for your nuts and bolts you can avoid thread stripping, deformations, and even bolt loosening while having the maximum possible strength for your connections.

AYA FASTENERS is one of the most reputable leading fasteners manufacturers and suppliers in China, we focus on assembly and fastening materials, supplying global customers with high-quality screws, bolts, washers, and nuts products over 20 years.

AYA has been deeply involved in the Fastener industry with a single-minded and dedicated attitude, devoted itself to providing our customers with more industry-specific, professional, standardized, and precise Fastener solutions. If you want more information, please contact AYA FASTENERS for the details.