That got me to thinking, these frames are so much better than most frames that I should let people who are not familiar with them know.
Bahco 225-PLUS Hacksaw Frame. I think they are also available under other brand names, but mine are Bahco.
I have three or four and they are the real deal. The one that failed the tension adjustment screw wore from decades of use and became hour glass shaped right where it goes through the toggle it threads through. Metal filings just wore the screw down. Probable dirt too. Replaced it with a socket M6-10 and will use an Allen key to change blades now, so all is well. It’s as good as new. The toggle didn’t have any appreciable wear. Go figure. When I pulled it out I thought I would find both were worn out.
I have some old Starrett screw slot cutting blades and I can attest to this frame being what is needed to tension them enough cut clean nice slots. They also make it far easier to make straight hacksaw cuts on any stock than any other frame I have used. Far easier.
The Starrett fine screw slot cutting blades were discontinued a long time ago, if you use a high speed rotary tool you can tension up a fine tooth hacksaw blade in a frame and grind the set off both sides of the teeth and make one. You can thin the blades and they will cut as nice a slot as a slot file, and everyone knows how expensive slotting files are.