Knife Material?

[pondoro]

I have three old power hacksaw blades. Two are 0.088" thick and 1.7" deep. One is 0.075" thick and 1.45" deep.

You can barely read on one where it says, "High Speed Molybdenum Stee...."

I would not want to reheat treat them but tempering in my oven would be an option. So the plan would be to grind away material without ruining the heat treat.

I know that "High Speed" steel is more resistant to temperature damage than other steels, hence the name - faster cutting speeds are acceptable without damaging the hardness.So I'd have a bit of margin for error but I'd still go slow and attempt to keep the metal cool.

Any advice? I know some of you are very experienced in knife making.

 

[Alden]

Don't hover on one spot for long but work length wise and wet.

 

[ohio ramrod]

All of the "molloy" tool steels I have worked with are very heat tolerant. They stay hard at higher heats than most other tool steels. I have used the industrial hacksaw blades as is. I shape them by slowly grinding and put the holes in the tangs for rivets with a tap burner. Most of the blades are a "two part" blade. The molloy tool steel is on the cutting edge and the rest of the blade is a softer steel. :idunno:

 

[pondoro]

These blades are old (like 1960's or 1970's), so I think they are less likely to be two piece, maybe not. Can you see a line if they have two compositions of steel or is it invisible?

 

[DOUBLEDEUCE 1]

I have a knife made from an industrial hack saw blade. It is one hard piece of steel and takes forever to sharpen. I gave the broken piece to a friend at work who made it into a knife for me.

An old neighbor who worked on the Golden Gate Bridge gave me the broken blade. He said the saw broke while he was cutting something on the bridge. This was during the late sixties. If the blade didn't have any sort of connection for me with the bridge or the neighbor, I would have tossed it out a long time ago. :idunno:

 

[newtewsmoke]

Can you see a line if they have two compositions of steel or is it invisible?

normally you can see the line where the teeth metal is fused to the junk metal, as far as i know tho, they are called and marked as bi-metal. The HSS blades should be good to go 4 ya, just dont burn 'em when grinding them into a knife. :wink:

 

[thecapgunkid]

what sort of knife do you intend to make? Have you drawn any patterns yet?

All of my hand made shoemaking and patch knives are band saw steel.

If you can break and grind it'd be a lot safer than heating and quenching, but that depends on the knife you want to make.

 

[pondoro]

Within the subject matter of this forum I'd like to make a camp knife with a striped maple handle. Outside of this forum's focus I might try a Japanese-style cooking knife.

I've already made a small camp / patch knife from a file.

 

[crockett]

About one million years ago I made a blade out of an industrial hacksaw blade and used a section of black bear bone (I shot the bear) for the handle- so it is a sentimental knife plus a really good knife. I've been told that the old blades had good steel throughout but the newer blades only have good steel in the teeth area. I don't know too much on metallurgy but I think the old blades had a small amount of nickel that accounted for a tough blade. HOWEVER I might be confusing Industrial hacksaw blades with circular saw blades. I know the old industrial hacksaw blades made good knives.
These hacksaw blades are around 3/32" in thickness. They therefore are best used in making blades that would have been thin- roach belly or scalper types, friction folders.
On tempering, I did a really barbaric method- heat to a dull red, maybe slightly more- quench, then temper in an old oven at around 450-500 for an hour, cool, then another one hour temper at 450-500. It came out okay for my use but obviously there are far better methods.
Hopefully Wick or Chuck might chime in as they have forgotten more than I've ever known on these things.

 

[Birddog6]

If it was made in the 70's it is all good steel, not like the new laminated edge blades.

I made 11 knives of one side of one deer antler back in 1974, using these old 2' long oare to this day & they will not wear out in 300 years. There is no possible way you can wear those blades out...... :shake: They are hard hard hard.... BUT takes allot of grinding & quenching & don't get them over hot. Hard to sharpen, but that is why they stay sharp too ! :thumbsup:

I never tried to drill them with a carbide bit, may can do it. Back in 1974, I took the blades & stuck them in a cup of water & froze the water, leaving the tang exposed. Took a torch & quickly blew a hole in the tangs. & then quenched them fast.

Be careful not to get grind marks on the sides of the blades, as you will never sand them out.

As said, HARD good material & don't need to harden or temper them, just take your time making them. Oh, and my grinder was a ? 500-600 RPB grinder at that time.

Keith Lisle

 

[TomWaits]

Back in the 70's I had access to some of the
molybdenum steel hacksaw blades. Made several pocket knives and a few fixed blade knives from them. Rockwell hardness was measured to be 72,thats hard stuff. The ends of the blades, near the mounting holes, can be drilled but nothing will touch the blade itself. Best way to mount them was to insert a tang into a handle rather then scales on the sides with pins. The pattern that I used for the pocket knives was a disassembled "Sodbuster". First knives took about a hundred hours to complete and at least half that was polishing and thinning the edge. If I could figure out how to post pics, I'd show a couple of them to you. Good stuff but hard to work with.
Tom

 

[TomWaits]

Here is a pic of the knives mentioned in my last post. They are tough and have all been used hard. Mostly retired now and will go to my kids.
Tom

 

[pondoro]

3/32 is just a bit thicker than the larger two that I have.

"Hard to sharpen" doesn't bother me, I've got more sharpening supplies than the average long hunter and I can sit around listening to music while I sharpen.

"Impossible to sharpen" would bother me, hence the original question - files need to be tempered or you'll never get them sharp, sounds like maybe High Speed Moly steel can be sharpened, with patience. I expect that the condition of these hacksaw blades is tough enough to function as a knife - whereas files can break if flexed. Another reason files get tempered.

I'd still be happy to have an opinion on tempering, would it help this steel?

 

[pondoro]

Here's the file knife. The blade is about 4 inches long. I tempered it in my kitchen oven and I kept it short for two reasons:
1) I was still afraid the blade might be brittle enough to break, shorter = less leverage to snap it off.
2) It is an accessory for a small flintlock pistol, a 36 caliber gun that a city dweller might carry into the country or a country dweller might take on a trip to town, leaving the "real gun" at home for his wife. I didn't see a large camp knife as an appropriate accessory for that pistol.

The bolster is made from a nickel, but I thickened it by "upsetting" it. The first bolster I made was drawn out to be tall enough and ended up too thin. So the second bolster I upset, then drew it out, ending up with a decent thickness.

For my hacksaw knife I'd like to make an English Trade Knife replica.

 

[TomWaits]

Pandora,
The hacksaw blades are a molybdenum alloy material which I do not believe can be tempered to any degree. They can see quite a bit of heat during cutting with no affect to hardness.Would be nice if they could be brought to Rockwell hardness around 63 or so. The rules that apply to carbon steel do not apply to alloys like this,I think the hardness is set by the proportion of elements manufactured in the steel. So, what you see is what you got to work with. Its laborious but you can make a knife that you will give you lots of rough use and satisfaction.
When grinding metals that may be affected by excessive heat, I do not wear gloves and cool the steel before it gets too hot to hold.
I just picked up one of the old blades at a junque shop for a buck a few weeks ago and have been thinking about what to do with it.
Tom

 

[pondoro]

Great discussion about why chrome vanadium molybdenum steels are hard to sharpen: https://www.youtube.com/watch?v=sdxf32F3j3k

 

[M. De Land]

I have a four inch wide belt glass grinding machine that bathes the work in water spray that would do the roughing out very nicely me thinks.