“Hole saws? That’s just a piece of metal with some teeth, right?”



“Hole saws? That’s just a piece of metal with some teeth, right?”?

Let’s discuss this concept.

Before we answer this question, let us provide some context. We will be explaining the development of the NVP technology and to assist us, we have invited Wagner Pivetta Zanardo, a PhD in Material Sciences and the R&D Manager at our state-of-the-art Excellence Centre in Brazil (Starrett Brasil). He will be helping us understand our product development process using the NVP technology as an example.

Fast Cut Hole Saw versus Deep Cut Hole Saw

When we check the Starrett range, we can find two “similar” saws. The same colour; pretty much the same stamp; and when you don’t see them next to each other, you may think they have the same height. And then, end-users and distributors can wonder: why should I have Deep Cut? Fast Cut is the Starrett worldwide best seller. I buy this one and “job done”.

The Fast Cut Hole Saw (FCH) is our most popular product. It has a height of 41mm and a constant pitch of 5.5 TPI with 30% extra gullet volume.

The Deep Cut Hole Saw (DCH) is designed for heavy-duty applications. It has a height of 51mm and a variable pitch (4-6 TPI), known as the NVP technology.

Both the FCH and DCH have extra cobalt for enhanced heat and wear resistance, improving the product’s life.

Physically, you understand the differences now. How about the applications? And the NVP?

Now, let us delve into NVP technology and its development.

While FCH is recommended for materials with a thickness of up to 3mm, the Deep Cut Hole Saw is ideal for solid materials thicker than 3mm and is recommended for cutting structural materials/pipes. The tricky application was the second one!

One of the biggest challenges in cutting structural metal with void space is avoiding tooth breakage and ensuring a successful outcome. To overcome this challenge, Starrett has incorporated the NVP technology (patent pending) into the Deep Cut range and redesigned the profile.

Combining thousands of hours of cutting tests and utilizing Finite Element Analysis (FEA), Wagner and his team successfully developed the NVP technology, which meets both the applications recommended for the Deep Cut.

FEA is a computer simulation technique that helps engineers predict how a product or structure will behave under different conditions. It breaks down the product or structure into smaller parts and models each part mathematically. By using computer software, Wagner’s team can simulate how the parts will react to different loads or stresses, and make changes to the design if necessary. This helps them create better and more efficient products and avoid potential problems before they occur. In simple words, FEA is like a virtual test to see how a product or structure will perform before you even have the tooth profile developed.

FEA can be used to simulate a wide range of conditions, including Stress and Strain, Thermal Analysis, Mechanical behaviour of structures, deflection, vibration, impact, Fatigue, etc. This is a topic that deserves a specific article.

During and after the development process, the dedicated R&D team collaborates closely with the tech teams at our global plants to conduct thorough field tests. Feedback from these tests is used to further enhance the software, and additional laboratory tests are conducted to create new samples. The final product is launched with confidence, as we are certain that it exceeds our customers’ expectations.


We think you are still wondering. What’s the meaning of the NVP abbreviation? This is very simple: New Variable Pitch.

What’s not simple is the technology and the dedicated people behind it, who bring you products that we are proud to associate with the name of our founder, Laroy Starrett. As an inventor ahead of his time, his legacy lives on through the products we continue to make.

Now, let’s be honest. Do you still think it’s just a piece of metal with some teeth?

You can find our Deep Cut range by accessing the Digital Catalogue: