What Is TPI?

A common term that’s used when talking about screws is threads per inch, or TPI, which might leave you wondering what exactly is TPI and how is it determined? Screw TPI looks at the thread count in an inch of a bolt. When looking directly at a screw, you are able to distinctly see and count the number of threads. To measure it, you can identify an inch-long section on the fastener and count how many peaks are on it. This process can typically be done by a user of the screw, as long as there are not too many threads.

Screw TPI is used for American fasteners only. In general, smaller fasteners have finer threads, producing a higher screw thread count. Screws that have finer threads are known for being stronger in tension. Contrarily, larger fasteners have greater threads, producing a lower thread count and less strength in tension.

How Do I Calculate TPI?

Luckily, you can easily convert metric pitch into TPI using a formula. Follow this formula to accurately calculate the TPI of your screw: 

Threads per inch equals the number of threads divided by the length of the thread

What Is Thread Pitch?

On the other hand, the thread pitch is the distance between two threads. This measurement is typically used in place of TPI for metric fasteners. It is calculated by measuring the distance from one peak to the next and is often measured in millimeters. The calculation of thread pitch can also be used in a formula that determines the screw’s thread count.

How Do I Calculate Thread Pitch?

If you already have some American fasteners on hand for your project but are looking for more, you can get the right size by doing some calculations. Follow this formula to accurately measure your thread pitch:

Thread pitch equals the length divided by the number of threads

TPI Vs. Thread Count

Something to notice when looking at thread pitch is that when fasteners have a lower thread pitch, they have a finer thread, which is the opposite when compared to the screw TPI.

While each offer different benefits to their applications, both screw TPI and thread pitch are used to measure the threading of a bolt or fastener to ensure that they can be secured properly. Without knowing these measurements, the bolt and nut could either seize or strip the threading and result in an unusable condition.

Selecting Your TPI Screws

When searching for your TPI screws, we have a large selection to choose from. For our line of TPI screws, we have the following options:

• 1/4 Inch – 100 TPI Screws
• 1/4 Inch – 80 TPI Screws
• 3/16 Inch – 100 TPI Screws
• .137 Inch – 80 TPI Screws

All of our TPI screws listed above are available in different lengths to fit your needs. Upon request, we are also able to create custom tips for your screws, with blunt or coned tips available. Also, at Kozak Micro Adjusters, we are able to offer screws supplied with specified drive variations upon request.

Due to our highly developed and custom-modified machinery, we are able to supply fine adjustment screws that exceed the industry standards. Please be aware that we do not guarantee that our TPI screws will be compatible with screws and bushings that are sold by alternative manufacturers. On this topic, it is also important to be careful when converting metric pitch to TPI in order to get the best fit for your project.

Our High-Vacuum Screw Options

Our high-vacuum compatible fine and ultra-adjustment screws are supplied with a ball tip which is made of hardened steel. These screws are able to have air escape from under the ball tip due to the design that causes a relief in the ball cavity. The options that we offer for your high-vacuum TPI screws include:

• 1/4 Inch – 80 TPI High-Vacuum Screws
• 1/4 Inch – 100 TPI High-Vacuum Screws
• 3/16 Inch – 100 TPI High-Vacuum Screws

If interested, we are able to create custom lengths and custom tips upon request. Our high-vacuum screws are able to deliver precision smooth movements, especially in the most demanding OEM applications.

Choose Kozak Micro Adjusters for your TPI Screws

We have been providing quality screws and products for over 40 years. Our standards exceed the standards of our clients, and we stand by our superior craftsmanship in creating TPI screws and beyond. We take pride in providing the highest quality products to meet the needs of your company. 

Contact us today to learn why our TPI screws exceed industry standards.