recycling a hacksaw blade

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Cliff Stamp

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This started off as a rusty hacksaw blade which was found outside which was buried under snow for most of last winter :



A 4.5 angle grinder was used to clean off the rust, apply a primary flat grind, shape the tip and taper the tang. The flat grind was done under water. This took about five minutes. It was then epoxied betweep two pieces of pine and left for 24 hours.

The handle was then chipped to rough shape with a Byrd Finch and then the blade grind was refined on a belt sander which also rounded the tip and shaped the handle. This took about five minutes as well.

I was hoping it was a HSS blade, but no luck, this was carbon, but still, it only takes about 10 minutes and you have a small utility/paring knife. The knife is really thin, it is only about 0.02" at the spine, 0.005" goes way up on the blade.

-Cliff
 
Ooh.... An xacto knife was one of my most used tools in the sign business and i always wished i could just touch up an edge instead of throwing it out but never bothered with sharpening disposable blades. There was also a perfect 'middle ground' of edge sharpness between new and dull that seemed to work best on various materials so i would end up throwing out blades that werent really dull yet. Of course the tips always snapped when i needed them most. I think the boys at the shop are getting these for christmas this year. Although def not a new idea, I never had time to spend on a project such as this. Now that im a full time student again, the sky is the limit.

Any idea what brand/model of blade might be the best choice in steel? (HSS)
 
You definately want a HSS version simply to reduce the change you damage the blade during grinding because HSS can tolerate very high heat. Plus it will also be much harder and much more wear resistant and more corrosion resistant. If you are serious about using HSS for knife making, David McDonald sells a variety of it basically at cost :

http://groups.google.ca/group/rec.knives/browse_frm/thread/2bee8a79b46052a5/

-Cliff
 
Edit: Thats even better, thanks.

"I was referring to which particular hacksaw blade model would best suit the project. I've got some lennox blades and some other random blades that i cant remember which brand they are. If i was using a new blade the eclipse brand hacksaw blades look pretty good, M2 steel."
 
FYI. Micro-Mark www.micromark.com sells a sharpener for "hobby knife" blades. It's item nr 81619 in their current catalog with a price of $23.60.

I have no financial interest in this company but have used them as a source of hard to find tools and "neat stuff" for years in my gunsmithing business. Now that the knife bug has bit me, they're an equally good source for a huge array of tools and products all in one place of use by knife makers and refubishers.

Their main focus is on the model railroad and boat community but, hey, tools are tools. I haven't seen some of their powered hand filers and a lot of other goodies anywhere else.
 
Nice project Cliff.

I saw a homemade knife years ago that was made from a very large, heavy hacksaw blade. The blade was about 5 inches long and about 1.5 inches wide and 1/8 inches thick. The teeth of the hacksaw blade were left intact along the spine of the knife blade. The blade tang was set inside an aluminum conduit and the conduit was then filled with molten aluminum. The handle was then formed by grinding.
 
Yeah, the thicker blades are likely more productive for longer blades as they are more rigid, you would want to hollow them to get the most out of them. Easily done with the angle grinder as well.

-Cliff
 
Is the hacksaw blade of the approx 0.5 x (10-14?) inches common variety? At the local hardware store they sell two kinds here, blue for bi-metal and red for HSS. I bought a HSS one a long time ago and prehaps it would be a good candidate to play around with. My only concern is that it is really flexible even in relatively short lengths.

Can you give more details on the reduction and grinding of the blade?
 
kel_aa said:
My only concern is that it is really flexible even in relatively short lengths.
Click to expand...

Yeah it is the normal hand hacksaw blade and it is really flexible. It is thinner at the spine that most knives at the edge. You really want about 0.050" for a knife of any length, 3-5" or so and leave the spine at that thickness.
Here is the highly skilled procedure I used to grind the blade :

-lay blade in groove in wood and fill with water
-burn a section of the metal intentionally to see what it took to damage the blade
-move to the actual blade part and lay down a series of lengthwise passes and increase in frequency towards the edge, make one pass on spine, two below it, three next, etc. . Since the height of the grind is proportional to the depth, ta da, you have a flat grind, high school geometry proves its worth again
-grind the tip shape and form the tang, this should actually be done first

Alvin has more detailed commentary on the grinding procedure as well as picture of the knives in progress as well as other projects from various individuals on additional knives. They all look way better than the above. How Alvin gets the precision he achieves on the equipment he uses is fairly impressive. Give most makers an angle grinder and ask them to hollow or better yet convex grind a blade and see what they say.

-Cliff
 
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