I made a thin parting off tool from hacksaw blade. The tool holder was made from 16X16mm black skin mild steel. After cleaning up the material was held on the angle vice at 30 deg and 1mm wide groove was cut.
Two grooves were cut. The blade would be held between grooves.
I cut the blade holding part by 1mm.
Deep 1mm wide saw cut was made remaining about 1.5mm.
I made a blade from carbon steel hacksaw blade. The blade was positioned in the holder and tightened in the tool post. The blade was fixed tight enough by the tool post screw. The both sides of the tool blade was ground about 30 deg to fit to the holder.