Method for shortening a hacksaw blade for metal

There are shortened hacksaws for metal, which require special short blades, which today are almost impossible to find on the shelves of our stores.
You can get out of this situation by shortening the standard hacksaw blade, which has a length along the mounting holes according to GOST R 53411-2009 from 250 to 700 mm. The most common length is 300 mm with a thickness of 1.25 mm. Just such a file is at our disposal.

Typically, hacksaw blades for metal are made of high-speed steel grades Kh6VF, V2F, as well as R6M5, R12, R18, etc. Our saw blade is made of so-called spring steel grade 65G. The marking indicates the manganese (Mn) content of the metal in an amount of 0.65%.

Steel grade 65G is characterized by increased wear resistance, but does not tolerate shock loads well, that is, it is brittle (this property will be useful to us in the future). But this steel has excellent cutting performance. The manganese present in it gives it such properties.

Will need

For the planned work we will need:

standard hacksaw blade;
feather drill bit for ceramic tiles and glass;
drilling machine;
pliers or pliers;
metal ruler;
emery wheel.

The process of shortening a standard metal file

1. Using a metal ruler, measure the length of the old file installed in the shortened hacksaw. It turned out to be equal to 155 mm at the centers of the holes.
2. Take a standard hacksaw blade and mark the location for drilling the hole, taking into account its shortening. In this case, special precision is not required, because the hacksaw can be adjusted in length. A deviation of ±2-3 mm does not mean anything.

3. We clamp a “feather” into the chuck of the drilling machine, which is able to provide a hole with a diameter of 4 mm, which is required by the above GOST.

First, we drill the canvas on one side, then turn it over and drill on the other.

We carry out the operation without tempering the metal so that the cutting properties of the tool are not affected.

4. Now you can shorten the file along a pre-designated line by holding it with pliers and sharply bending the excess part with your free hand. Due to the fragility of the metal, fracture will occur without excessive force.

5. If the fracture still does not occur in the intended place, then this inaccuracy can be corrected with the presence of second pliers. Again, use one pliers to clamp the file along the mark, and with the second we bend the remaining piece and it will definitely break off along the mark.
6. Now all that remains is to round off the fracture site on an emery wheel and use the shortened file, securing it in a hacksaw, for its intended purpose.