One of my Bahco high tension hacksaw frames went kaput

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.

I make the screw cutting blades on the surface grinder. lay the blade on a piece of paper on the chuck and turn magnet on. the grind set of the first side. Then flip grind the set of and clean up blade. flip again and grind to thickness. The sheet of paper keeps the set teeth from damaging the chuck and aids its not slipping.

I have several of this style frame also they are great and tension a blade mush better and straighter.
If you thin a hacksaw blade you have to be careful with this frame as it can pull the eyes out of the blade.

“If you thin a hacksaw blade you have to be careful with this frame as it can pull the eyes out of the blade.”

Oh boy, don’t I know that.

I went out looking for a winged bolt. I think McMaster Carr may have them. With that socket cap screw it would be no problem at all tearing the eye out of a regular hacksaw blade using an Allen wrench. I’m inclined to cut the original tensioning screw off and weld a new one on, or what might work better is welding a 3/8 or 7/16 wing nut onto it. One or the other should slip over the head.

Bahco made some of the best tools.
Someone bought them out a while back
Sandvik I believe
SnapOn owns them now

Sandvik made great hacksaws and blades.
I don’t think they make them anymore, though.
Cutting large copper and galvanized pipe was far easier with their product than the other brands available at the time.


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Like most tools learning to use them correctly is the big thing. A hacksaw can do very good work cut only on the push stroke the blade dosnt cut in 2 directions. Cut at a push speed thats appropriate for the stock. Learn a square straight push. When your pushing the hacksaw correctly you will see a flow of chips with a smooth easy feel. Once you learn this push blades last much longer and stay sharp longer. If you pull teeth at some point on the blade your push isnt straight and square so your pinching the blade. Another is to keep a minimum of 3-4 teeth in contact with the work, you may have to angle the cut on thin work but this gives a much better finish and dosnt grab or chatter.
When your going right its just a smooth steady push. As you learn the paint on the blade should last thru 4-5 cuts before it shows real wear.

Not having had a teacher, I set my hacksaw to cut on the pull of the stroke not the push. That worked better for me, what am I doing wrong?

Tim

Not a thing as long as your not trying to cut both ways

Having made thousands of hacksaw cuts, this "how to" explaination is right on. I too liked the Sandvik saw wearing out many of them cutting conduit.

Quote:

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Originally Posted by country gent

Not a thing as long as your not trying to cut both ways

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Good to know, I just get less binding when I draw instead of push. I draw with my right hand and control the pressure with my left on the top of the bow. Does anyone make a hacksaw with a handle on the top of the bow as well as the one on the end?

Does anyone ever clamp the bow in a vise and draw the stock along the blade with two hands one on each side of the blade? I do this with things I don't want to clamp in the vise because the can't take the pressure, thin walled tube or brass cartridges. I have a couple x-acto saws but blades are expensive and fragile. I find the idea of screw slot cutting blades interesting. I could use blades with a finer kerf, the x-acto blades will not cut steel.

Tim

The only thin screw slotting blades I am aware of were discontinued. Starrett. The files are very expensive and I have found them very delicate.

If a guy slots a lot of screws my buddy made a jig that has a 1/4 inch drill chuck to hold the screw and an arbor for the small diameter metal slitting blades. He sets it up in his milling machine, but I would think it could be set up in a drill press.

In my toy box in the shop is a 1/2" jacobs chuck on a 4" long 1" square shank.The chuck is 1/16-1/2" range and 1/2 20 threaded. I use it in the mill, the bench vise, and when available shaper. This is similar to a collet block. It allows cutting squares driving flats octagons screw slots. The big plus to it is it dosnt require the long tool shanks the rotary table dividing head and collet blocks do.
The thin slotting blades are fragile and need to be ran carefully. I dont know if the drill press spindle would be solid enough or an x-y table fine enough to use them. run out wouldnt be the issue but the spindles end play will

I currently have a 5c collet chuck mounted on my rotary table and it is good for clearance and works great. but its not as quick and easy as the above drill chuck.

Im going to build a bench top filing machine that will be handy for slotting and forming shapes. Here the screw slotting blades will only need to be 6" long.

I have several more or less high tension saw frames and they do make a big difference. The Amazon page for your Bahco 225 has a photo of the Bahco 325, which I discovered during some internet research. I just ordered a 325.

The Starrett screw slotting blade set I have was purchased, along with a LOT of other tools, in 1976. The blades are all 8 inches long, which is too short for most modern hacksaw frames. However, the old cast iron Millers Falls (Star) 8" frames are a perfect mate.

Several years ago, I single handedly made the ebay market for these cast iron saw frames and watched the prices climb as a result and after I loaded up on them. Their handles are straight and in line with the blades, making handling quite natural for precise work. They are the berries with Starrett fine tooth blades.

My Starrett slotting blades are 12 inches. They were used when I got them. I keep them locked up and hidden from the kids. I bought my frames used too.

Mine are all 12" ground from Bi metal blades. They are getting long in the tooth but still going. I too am fussy about who uses them. Its amazing how long they will last.