01/19/2021 | Industries & applications

PRECISION MATERIAL: STEEL STRIP FOR SAW BLADES

When optimizing materials, it’s important to keep the processing stages and also the final application in mind. Cold rolled steel strip for saw blades is a prime example. This is used, among other applications, as martensitically hardened and tempered steel strip for traditional jigsaws or circular saws. Things become particularly demanding in industrial sawing applications, however, and here Waelzholz Brasmetal supplies this high-quality steel strip in a variety of application-optimized grades. Saw blades for stone gang saws, for example, which are used to cut extremely hard materials such as marble and granite, need to be manufactured from one of these grades. In addition, the raw steel for wood band saw blades used to cut tree trunks is produced in Brazil under the brand name Baukus®.

“Industrial sawing applications place high demands on properties such as the saw blades’ resistance to wear, service life, and dimensional tolerance. Optimum performance can only be achieved through coordinated production across all stages of the value chain,” explains André Sereno, Global Manager Martensitic Steels at Waelzholz. In the case of blades for wood band saws used in industrial applications, for example, steel strips up to 14 meters (551 in) long are welded together to form a circular segment. This saw blade then runs like a belt around two guide rollers (see figure). According to Sereno, “perfect dimensional tolerance is required in this case, because vibrations of the saw blade significantly reduce its service life and increase the loss of the cut material at the kerf.”

Maximum cutting precision thanks to perfect saw blades

The challenge when manufacturing blades for wood band saws is accurately welding together the ends of the saw bands – which can be up to 14 meters (551 in) long – without creating warpage in the blade that would lead to vibrations. The perfect straightness of the raw steel is an important factor in this respect. “We produce our Baukus® steel strip with straightness in the range of up to one thousandth of a millimeter over the entire length of the coil’s core, creating the perfect conditions for saw blade production,” says Sereno. In real-world terms, the straightness of the raw steel means that saw blade manufacturers no longer need to implement a separate straightening process, thereby manufacturing with much greater efficiency. This is a real advantage for Waelzholz customers. In addition, the weldability of the steel strip is an important criterion for the production of saw blades. “Thanks to its chemical composition, our Baukus® material is ideally suited for joining via welding. This allows our customers to produce a completely warp-free saw blade,” Sereno notes.

Sawing marble and granite – a hard task

The material properties of Baukus® steel strip for wood band saw blades have been optimized over the course of many years at the Waelzholz plant in Brazil. This experience also benefits customers when it comes to manufacturing saw blades for cutting marble and granite. For this purpose, saw blades with a length of about five meters (197 in) are clamped into special saws known as stone gang saws. Marble and granite are extremely high-quality materials. The stone gang saw must cut perfectly so as not to damage the rock beyond the kerf and potentially render the workpiece unusable. As Sereno explains, the material’s outstanding flatness and lack of warping are also crucial for perfect sawing results: “Marble window sills, for example, are only one centimeter (0,39 in) thick. In order to avoid material loss as far as possible in this application, the cutting tools must operate with extreme precision. Another advantage is that the uniformity of the cut prevents striations in the high-quality material.” Waelzholz’s steel strip for saw blades meets these requirements effortlessly, because it is literally made for these tasks.

Stone gang saw for marble and granite

A perfect edge at a 90-degree angle

Another highlight of the special steel strip for saw blades used in stone gang saws is the ground right-angled edge at an exact 90-degree angle. The expert Sereno explains why meticulously ensuring that the material has this angle is so important to customers: “In the saw blade manufacturing process, the teeth of the saw are brazed onto this edge with diamonds. If the edge wasn’t exactly right-angled along the entire length of the material, the attached saw teeth wouldn’t produce a perfectly straight line, but would instead stick out to the side. On our edge produced with extreme precision, the saw teeth line up perfectly. This ensures that the kerf is as small as possible.” This level of precision reduces both saw teeth wear and the loss of high-quality stone material to an absolute minimum. With saw blades made of high-quality cold rolled steel strip from Waelzholz, even the challenging task of cutting granite and marble is being solved reliably and efficiently.

Would you like to learn more about our precision materials for industrial sawing applications? Click here to download our data sheets: Steel strip for wood saws (Baukus®), Steel strip for stone gang saws.