Let’s take a close look at one of the most versatile types of saw, from large specimens in the industrial sector to micro ones intended for precision work.
The circular saw is defined in this way precisely because it uses disk-shaped blades, the diameter of which can vary according to the standard possessed by the model and its dimensions; the first copy of circular saw was invented in 1775, by the English carpenter and engineer Walter Taylor.
At a young age Walter Taylor, serving in the British Royal Navy, was intrigued by the rigging blocks used on ships which, being handmade and therefore not squared with precision, were the cause of problems and exposed the sailors to serious risks. Thanks to the invention of the circular saw, Taylor was able to produce precisely squared rigging blocks, greatly increasing their quality and above all safety, which earned him a supply contract with the Royal Navy.
The evolution of the saw
Over the years and thanks to technological progress, circular saws have evolved on three different paths that have originated as many versions of the same, which in addition to wood are also able to cut plastic and metals. The three different types currently in use, therefore, are the portable circular saw, the bench saw and the radial miter saw.
The portable models are distinguished by their compact size and low weight, so as to be light and easy to handle as they must be grasped and slid freehand along the cutting line of the piece; the latter is placed on a work surface and secured to the guides, so as to remain immobile and allow a precise cut.
The bench saws, on the other hand, are stationary machines where the circular blade is placed in a fixed position, usually in the immediate vicinity of the motor, and it is possible to move it only to adjust the angle of inclination; while it is the piece to be cut that is slid along its toothed edge with the aid of a trolley, or simply pushing it by hand along the blade after securing it to the cutting guides.
The radial miter saws are also stationary machines, unlike the bench saws, however, the blade-motor unit is placed on an articulated arm located above the work surface; the piece to be cut then returns to being positioned on the work surface, secured to the guides in order to remain motionless, while cutting is carried out by lowering the blade directly onto the piece and sliding it on the appropriate rails.
The main technical feature that distinguishes circular saws is the blade, as mentioned above, whose diameter can vary from 140 to 315 millimeters depending on the type; it goes without saying that the models with the largest blade are designed mainly for professional use, on construction sites or in carpentry and carpentry workshops.
The circular table saws with a blade up to 254 mm, on the other hand, and the portable circular saws, which usually employ 140 mm blades, are mainly intended for the hobby sector, but depending on the construction quality and performance offered by the various specimens may also be suitable for non-intensive professional use.
The blade is driven by a universal electric motor with one or more reduction stages, depending on the type chosen, which gives a variable speed in an interval between 2,000 and 5,000 rpm.
Circular saws for spindles, which fall into the category of precision micro tools, are an exception. These blades can have a diameter ranging from about 18 to 33 millimeters and can be adjusted at speeds between 5,000 and 20,000 rpm.
Make the best choice
As you could easily guess, at this point, even the best bench saw is certainly not suitable for cutting high thicknesses. The structural scheme of the machine, in fact, characterized by the motor placed almost close to the blade, means that only a small portion of the same comes out of the arm or the work surface.
Circular saws can only cut pieces up to a maximum thickness of 140 millimeters with perpendicular inclination, and since the blade can be inclined to perform angled cuts up to 45 °, the maximum thickness for the latter is reduced to about 113 millimeters. These measures are obviously not standard, and as for those of the blades, they vary according to the type of circular saw.
The bench saws in the hobby sector, for example, have a cutting depth that varies from 30-35 millimeters of the smallest specimens up to 80-100 millimeters, while those in the artisan and professional sector are characterized by a depth of cut between the 100 and 140 millimeters; as regards portable circular saws and micro-tools, on the other hand, the cutting depth is further reduced, ranging between 40 and 90 millimeters depending on the model and size.
The same applies to radial saws where the blade-motor unit, although placed in the reverse position, usually has the same characteristics as that of the bench saws, the only substantial difference between the two types of the machine lies in the maximum length of the pieces workable.
In fact, that allowed by the cutting-off machines are reduced due to the particular design of the guides, which in addition to making the cut precise have the task of blocking the piece. The bench saws, on the other hand, do not limit the length of the workable pieces, since it is the latter that are mobilized and pushed along the work surface.
The intended use
The processing of freshly cut logs requires large stationary machines, therefore industrial circular table saws are very large and heavy and are used only after band saws have done the bulk of the work by cutting the logs into smaller slices.
Consequently, the largest market segment is the hobby and artisan sector; in this range, most of the bench saws, radial miter saws, and portable circular saws are concentrated, with a further subdivision based on price and quality aimed at distinguishing between the specimens intended exclusively for amateur use and those suitable also for artisan and professional use.
Micro tools, on the other hand, have a different market niche, since these are used in precision mechanics and therefore affect a range of users that is less extensive but far more expert and highly specialized, both in the professional and amateur fields.