Comparison GRUNTEK Piranha vs Tajima JPR-265

The total length of the hacksaw blade.

The value of this parameter is directly related to the saw type (see above). The general rule for choosing is as follows: the blade should be twice as long as the thickness of the largest workpiece that is planned to be sawn. This will provide an optimal range of motion to avoid unnecessary fatigue, and the tool, on the other hand, will not be too bulky. However, a long blade tends to spring back, so when working with hardwoods or other difficult-to-cut materials, shorter saws can also be taken. And in models with interchangeable blades (beam and jigsaw, some mini-saws), length data will be required to search for spare blades.

In general, for simple household tasks for sawing wood, a length of 280 – 300 mm is considered optimal. For a private house with a garden, simple construction work, you should pay attention to larger models — up to half a metre. And the largest two-handed saws can have a length of 1000 mm and even more. More detailed recommendations on the optimal blade length for certain tasks can be found in special sources.

Density of teeth in a complete saw blade; measured as the number of teeth per blade length inch (TPI).

The higher the TPI, the smaller each individual tooth, and vice versa. Other things being equal, large teeth allow you to cut easily and quickly, but not very accurately; small — provide an accurate and clean cut, but at the cost of increased effort and time. Accordingly, when choosing a saw for this parameter, one must proceed from the fact that in this case it is more important — speed or accuracy. In addition, the TPI determines suitability for small workpieces: the smallest allowable log thickness is considered to be a three-tooth pitch. For example, in a 9 TPI saw, three teeth will take up 1/3", or approximately 8.5 mm.

It is worth remembering that only tools of the same type and purpose can be compared by the number of teeth per inch. So, for example, in standard saws for wood, the minimum TPI value is 4, and already in passer saws — 9. The most coarse-toothed today are saws for foam concrete — they have about 1.2 – 1.8 teeth per inch; and the “record holders” in terms of density are saws for metal and jigsaws, for which the TPI value of 24 is almost the standard.

The type of additional coating applied to the regular hacksaw blade (if such a coating is provided at all).

- Anti -corrosion. A coating designed to protect the canvas from corrosion. The tool steel from which modern saws are made is not stainless; therefore, if the tool is planned to be constantly used outdoors or in conditions of high humidity, this feature will not hurt.

- To reduce friction. A coating that reduces the friction force of the blade against the material being cut (usually wood, since this feature is mainly characteristic of saws for this material). Such a coating performs several tasks at once: it facilitates the movement of the hacksaw, reducing fatigue, reduces the degree of heating of the blade (and its tendency to deformation) and reduces the likelihood of jamming the tool in the cut.

Availability of an overlay on teeths in a set of delivery of a hacksaw.

Such an overlay, in fact, is a simplified version of the cover (see below), covering only the most dangerous and at the same time delicate part of the canvas — sharp teeth. A saw with a guard installed can be safely stored and transported without fear of contact between the teeth and surrounding objects (which could lead to both damage to these objects and damage to the blade). At the same time, the pads are more compact and cheaper than full-size cases.