At first sight a saw blade might seem to be a relatively simple product. But the fact is that a saw blade is very complex and it passes a wide range of stages during manufacturing, a lot more than people in general think. The description of the manufacturing process and its different stages can be found below.
Swedex designers transmit customer specific requirements and machine technical conditions, produce the drawings and prepare the production documentation. The blade production number is the blade’s identity and this gives us full information in the future regarding dimensions, cutting geometries and tolerances, tension images and flatness.
The steel used in our saw blades is of the highest quality. It is hardened to give a combination ofincreased strength and stability to the saw blade. The steel is laser cut and tempered to the correct hardness depending on the saw blade’s area of use. It is very important to perform the heat treatment correctly in order to get the hardness, toughness and evenness to harmonise with each other. With an all too hard raw saw blade, cracks can develop by high stress, but on the other hand an all too soft raw saw blade tends to bend by side pressure.
The saw blade is drawn in a CAD program. A special module is used for calculations and optimising of every saw blade. The body of the saw blade is cut out via laser and the dimension of the steel is adjusted to minimize the waste. We have a wide-range of steel sheets in stock with varying thicknesses and dimensions. The saw blade’s area of application determines the type of steel used.
Tempering is one of the most important steps when manufacturing a saw blade. During this process the steel body is heated to around 430°C during the night. Tempering results in a better balanced saw blade and also releases tensions in the material. By adjusting the oven temperature the correct steel hardness can be obtained. The hardness is adjusted for each specific saw blade.
Inspections and measures are performed throughout the manufacturing process. This is done to discover inherent mistakes as early as possible.
The quality of the centre bore is essential for the saw blade’s performance. A saw blade with a poor center bore will never work properly. In addition to turning the center bore to the correct dimension it is crucial to obtain an even and perfect surface. Furthermore the centre bore has chamfers on both sides for increased quality.
To achieve a good cutting result the saw blades must be tensioned to the specific rotation speed and area of use. Tensioning is made by rolling circular tracks into the saw body causing tensions in the steel.
The saw blade passes through our levelling machine, which ensures the blade becomes absolutely flat. This is a vitally important operation as a very flat saw blade allows us to manufacture to the tightest tolerances which in return gives us the best cutting performance.
After being brazed, all saw blades are checked for straightness and tension using a straight edge and dial gauge to ensure the blade is in the best conditions before grinding.
Swedex has throughout the years produced more than 16 000 different models of saw blades with very varying kerf (ranging from 0.9 mm to 13 mm). Despite a comprehensive stock of steel sheets it is impossible to stock all steel dimensions. Therefore surface grinding is used to adjust the thickness of the steel to the correct dimension.
To obtain the best cutting result the saw blade must be levelled. To increase the extent of levelling the saw blade is levelled by using a straight edge and a hammer. This skillful job takes many years to learn. By this operation the flatness, run out and cutting result of the saw blade is determined.
To obtain the absolutely best brazing result it is essential to get both the carbide tips and the saw body completely clean. Otherwise the silver solder used when brazing will not attach. To clean the seats on the saw body (where the carbide tips will be fastened) we use a blasting method with metal sand.
The carbide tooth is brazed on the seat of the steel body using a silver solder. Several different types of silver solders are used, but the most common is a three layer silver solder with a copper inlay. This reduces the risk of cracks in the carbide during the brazing operation.
Brazing is a precision task during which the tooth is held completely still while it is heated to more than 700°C. We use fully automatic soldering machines with robot loading for an efficient production.
During the brazing operation the saw blade is heated causing discolor in the periphery around the carbide tips. In the past sand blasting was used to reduce the discolouration. The disadvantage in using this method is the fact that the saw body becomes rough which reduces the lifespan of the saw blade. Therefore we have chosen an alternative that removes the discoloured area by polishing using a steel brush. Swedex was a pioneer in the use brushing instead of sand blasting.
During the entire production process is controlled blade tolerances. Our employees’ high skill and experience create the highest quality for our users.
To achieve a good cutting result the carbide tips must be ground. All sides of the carbide tooth are ground, and the grinding varies in terms of angles and shapes depending on type of saw blade and area of use.
The first operation when grinding the carbide tips is front grinding, during which the front (also called the chest) of the tooth is ground. The front can be ground in several shapes: straight, hollowed or angled. The most common type is straight, but the hollow ground front will result in maximum sharpness and the best cutting performance.
The most important grinding of the tooth is the side grinding. Faulty side grinding of one single tooth could cause a nonworking saw blade since the tooth will scratch into the material to be cut. Swedex uses the latest machines on the market to ensure a high grinding quality. The side grinding can also be varied, and we offer standard or cambered sides for best cutting performance.
The last grinding operation is top grinding. The top of the tooth is ground differently depending on the material to be cut and taking into account whether the saw blade is to be used for cross cutting or ripping etc. Swedex has several automatic robot lines for top grinding to obtain efficiency in the production.
The manufacturing process ends with a final check using a CNC controlled measuring machine. With four cameras and image processing measuring cutting geometry with very high accuracy. The machine measures saw body and the teeth on all sides. The cameras also check every braze and the pitch of the teeth. All measurement data is presented and stored electronically in image and graphic formats.
All final checks are carried out on our CNC controlled measuring machine. Using four cameras giving the highest accuracy of imaging, the machine measures the total cutting geometry of the teeth and the centralization of the tip. Also the machine measures the brazing of the tips and records any deviation which is then passed back to the brazing robots for any adjustments.
Swedex Blade Master is a process simulation machine from Finnish Veisto OY and uses a controlled powerful and irregular airflow to simulate the lateral pressure and stress that the saw blade will be subjected to during use. The machine measures how the blade reacts when operating at the correct rpm and feed rate. The measurements provided enable us to tension and balance the blade to a very high accuracy. The information provided also allows us to establish the optimum spindle, or the so called critical rotation. All the processed information is stored in the computer and can be displayed graphically.
A CNC controlled measuring machine for measuring, monitoring and documentation of both tension images and values. Our design engineers enter the desired values of the customers correct blade which has the optimum cutting results. The equipment can then measure and document the entered values. As a producer, we will manufacture the blades to the desired specification in a controlled process which can be replicated every time. The machine is used in conjunction with our process simulation machine resulting in our customers receiving a blade that works to its optimum every time.
All saw blades have a laser marking with logotype and information regarding type of saw blade, production data, batch number and the date of manufacturing. Standard non-specific saw blades are placed in our finished goods inventory with more than 40 000 articles.
We cooperate with a number of forwarding agents depending on the destination and the size of the goods to be sent. This enables us to offer our customers the best delivery service. We have daily deliveries from our manufacturing site in Mjölby, ranging from single saw blades in envelopes and parcels to full pallets with articles.
Tradition, crafts and skills in interaction with modern technology creates Swedex sharpness.
Highest quality from standard to specialty, together with the customer, we lead development.
We always put the customer at the center, and the Swedex stands for honesty, safety and quality from inquiry to delivery.