My Old Landy
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I know, but I am on a three minute time ban not the luxury of ten minutes like you 250 sub types!Quality not quantity mate.
- Thread starter h-dom
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DAPPH
as dyslexik as I'm daft
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Why extend the scales putting some brass or copper rivets in the two hole & rivet them in tight to fill the holes then grind back & and polish the scales & the heads flat to make it an unusual feature . I feel it would look good if the scales were 3 mm past the holes going along the bladeMust be something in the air....
Yesterday evening decided to finish off some no spin throwing knives that have been kicking about for a while now.
They are cut out of "annealed" quarter inch truck spring.
Being quarter of an inch thick (!) they need some substantial lightening holes in the handle for balance and to stop them sinking an inch deep in the target board.
It was a disaster! They are not fully annealed and my spurious collection of random drill bits won't touch it. It may be work hardening but on one occasion I ended up with a huge dimple pressed through one side where the drill bit just wouldn't bite. So I chucked it in the forge and punched the holes through with a drift. Yeah, ugly as sin and I'll have to open up the holes with a cutting disk. The other three blanks went into the forge, red hot and two left in there to anneal, one dipped in a bucket of vermiculite.
While I was doing that, it occurred to me I better finish this off so that I can claim it to be my first knife. Heat treated, O1 toolsteel, quenched in chip fat oil. Still arrow straight.
It is a copy of a Gough custom because I just love the look of the blade. It went glass hard so tempered in the oven at gas mark 6.
Reason I lost interest in this blade is I have two "precision" holes for fixing the scales and a load of "random" lightening holes.
...I stoopidly drilled two random holes right in front of the handle where it will show unless I extend the scales to cover them up which will make it look "bulky".
I'll do it anyway, not exactly an EDC anyway, no one's going to see it except you guys.
When you ground the blade was it a dry band machine or a wet sand stone wheel?
Screwdriver
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That's a very good idea thanks. One of my favourite aphorisms "if you can't fix a fault, make it a feature" springs to mind. I'll have a good think about what you suggest while I draw up some scales.
I think I did the bulk of it on the linisher but being 6 inches wide it is basically "one sided" with all the gubbins stopping you from using both edges. Then when it became clear a full bevel was going to produce a very clean interesting looking edge to the ricasso, I went nuts with hand sanding!
The edge of the blade is also a LOT thinner than it is wise to produce prior to heat treat, especially in one spot but incredibly, time and a couple of normalising cycles mean it is ruler straight. I will be hand sanding to finish.
DAPPH
as dyslexik as I'm daft
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Tempering High carbon steel /cold steel decent pre 1970's leaf spring a & blacksmiths / farriers rasps ............
Tempering / Heat treating using a 14 to 56 pound block of mild steel/cast iron heated to dull red in a coal forge is one way of tempering that's good for thin things after the initial forging and a little grinding .
Heat to just up to bright cherry red to normalize the steel part , let it cool on it's own in the air to very hand hot or colder ( spit on it if it sizzles it's still too hot ) . This helps stop bends & twist in the part
Reheat the part to dark cherry & quench in room temp water , it will be brittle & have hardness but won't crack if you haven't over heated it & you've destressed/ normalised it properly . Drill your pin holes or thread the tang etc .
The metal will have darkened on the surface . Now whilst it's cooled polish the par / blade to be tempered with a fine emery cloth so you can see nice bright metal .....whilst the block is heating to bright red .....not orange or white hot & burning . Then lay the blade along the block keeping the last 3/4 inch or so of the cutting blade side edge off the block watch the colours change on the back of the blade and move in the direction of the blade edge .
Here's the skill bit.... just before it gets to light straw get ready to whip it off and plunge it into room temp water ..as soon as it gets to a mid gold colour ,don't let the light straw gold turn into dark brown straw. or you'll start to lose the temper .
That will give you a very good quality tempered edge that will take hundreds & hundreds of light re-sharpenings .
In the olden day's
when I t'wer a lad in the 1950's .
Me dad ( a Sheffield born & bred steam hammer forge boy " said the cutlers blanks were stamped out twice & fettled to almost the finished blade size , the hot block tempering method was used in the 1920'& 30's there was not much grinding of tempered metal left to do. It's also how I was taught to make my own six punches and five chisels set during my apprenticeship in 1966. - 1969.
Obviously nowadays there's all new fangled ways of hardening & tempering ways for different grades of steel & steel alloy's but for decent pre 1970's leaf spring chisels & knives it still very good .
Tempering / Heat treating using a 14 to 56 pound block of mild steel/cast iron heated to dull red in a coal forge is one way of tempering that's good for thin things after the initial forging and a little grinding .
Heat to just up to bright cherry red to normalize the steel part , let it cool on it's own in the air to very hand hot or colder ( spit on it if it sizzles it's still too hot ) . This helps stop bends & twist in the part
Reheat the part to dark cherry & quench in room temp water , it will be brittle & have hardness but won't crack if you haven't over heated it & you've destressed/ normalised it properly . Drill your pin holes or thread the tang etc .
The metal will have darkened on the surface . Now whilst it's cooled polish the par / blade to be tempered with a fine emery cloth so you can see nice bright metal .....whilst the block is heating to bright red .....not orange or white hot & burning . Then lay the blade along the block keeping the last 3/4 inch or so of the cutting blade side edge off the block watch the colours change on the back of the blade and move in the direction of the blade edge .
Here's the skill bit.... just before it gets to light straw get ready to whip it off and plunge it into room temp water ..as soon as it gets to a mid gold colour ,don't let the light straw gold turn into dark brown straw. or you'll start to lose the temper .
That will give you a very good quality tempered edge that will take hundreds & hundreds of light re-sharpenings .
In the olden day's
when I t'wer a lad in the 1950's .Me dad ( a Sheffield born & bred steam hammer forge boy " said the cutlers blanks were stamped out twice & fettled to almost the finished blade size , the hot block tempering method was used in the 1920'& 30's there was not much grinding of tempered metal left to do. It's also how I was taught to make my own six punches and five chisels set during my apprenticeship in 1966. - 1969.
Obviously nowadays there's all new fangled ways of hardening & tempering ways for different grades of steel & steel alloy's but for decent pre 1970's leaf spring chisels & knives it still very good .
Last edited:
Screwdriver
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Well it may be "new fangled" but I always take my materials up to critical temperature before quench. For the O1 toolsteel above, I took it to bright orange and kept it there for as long as I could stand the heat, then quench immediately in chip oil. I would use new fangled quenching oil but I am way too tight to even consider it.
Then temper in the oven at gas mk6 along with pizza (which was nice). Was aiming for a straw temper and hit it too.
Scales came from my garden a year or so ago and have been resting in the house. They will go on raw and if they crack or split, I'll make some proper ones. I think these may be Laburnum.
Made up a sanding block from a bit of fencepost and a chopped up sanding belt.
Then temper in the oven at gas mk6 along with pizza (which was nice). Was aiming for a straw temper and hit it too.
Scales came from my garden a year or so ago and have been resting in the house. They will go on raw and if they crack or split, I'll make some proper ones. I think these may be Laburnum.
Made up a sanding block from a bit of fencepost and a chopped up sanding belt.
Screwdriver
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I remember sort of annealing my truck spring throwing knives but I obviously didn't do it right. Went two ways this time, heated to bright red ~750/800C and left two of them to cool slowly in the forge and one in a bucket of vermiculite. The two forge ones were still warm this morning, the one in the bucket was stone cold.
Soon find out if I can drill them. If I can't I'll need some other way to anneal them because punching holes in them is too much of a chore (and I bent my punch on the last hole).
DAPPH
as dyslexik as I'm daft
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Just checked on what I was thinking when you said what you were going to use for handles , all parts of laburnum including laburnum wood is poisonous .. so perhaps a bit of a no no for a knife handle that may give you splinters or lay on wet foods etc. " Is laburnum wood poisonous ? - Bing "Well it may be "new fangled" but I always take my materials up to critical temperature before quench. For the O1 toolsteel above, I took it to bright orange and kept it there for as long as I could stand the heat, then quench immediately in chip oil. I would use new fangled quenching oil but I am way too tight to even consider it.
Then temper in the oven at gas mk6 along with pizza (which was nice). Was aiming for a straw temper and hit it too.
Scales came from my garden a year or so ago and have been resting in the house. They will go on raw and if they crack or split, I'll make some proper ones. I think these may be Laburnum.
Made up a sanding block from a bit of fencepost and a chopped up sanding belt.
Screwdriver
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That is why I want to use it, I discovered it is poisonous after I chopped a bit of it down. However, I am not going to eat it so I think I'll be safe.
DAPPH
as dyslexik as I'm daft
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Bags I first trawl through your gear when you've snuffed if from Laburnum poisoning from the knife handle on your wet skin . 
PM me I'll let you have my contact details for your will . 
Screwdriver
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Unlikely since it is often used for woodwind instruments such as flutes.
As for my impending doom, while there may actually be not long to wait, you'd be at the back of a very long queue.
My Old Landy
Engineering Mayhem
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The blade and handle are top quality
superb.Shiny Steve
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good effort with that, the oak looks stunning, nice finish as well
h-dom
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Next step is to up my game a bit, so I have been experimenting with the san mai technique. This is mild steel outer layers and leaf spring core. It forge welded up perfectly as you can see where the steels welded in he photo but when I quenched it developed a huge shear right down the middle of the spine. Not on the weld, right through the core of the leaf spring. I've read this is because as it is quenched the carbon steel expands and because it has nowhere to go it shears itself. An edge quench is supposed to cure this.
I thought I would grind it and finish the blade just to see how it comes out and this is it after 2x20 minute etched in ferric chloride. I'm trying a coffee etch now.
I thought I would grind it and finish the blade just to see how it comes out and this is it after 2x20 minute etched in ferric chloride. I'm trying a coffee etch now.
maybe Martempering would do it......ideally though you need to know the grade of steel
Martempering/Marquenching - Hardening and tempering - Bodycote Plc
Interrupted quenching of steels typically in a molten salt bath, at a temperature just above the martensitic phase. The purpose is to delay the cooling for a length of time to equalise the temperature throughout the piece. This will minimise distortion, cracking and residual stress.
www.bodycote.com
h-dom
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I had seen something about ghat but not read into it, that's a good link, thanks. I still have half of the billet left so I will try that when I next have a chance.maybe Martempering would do it......ideally though you need to know the grade of steel
Martempering/Marquenching - Hardening and tempering - Bodycote Plc
Interrupted quenching of steels typically in a molten salt bath, at a temperature just above the martensitic phase. The purpose is to delay the cooling for a length of time to equalise the temperature throughout the piece. This will minimise distortion, cracking and residual stress.
Screwdriver
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Tanto looks really nice. Shame about the san mai.
Another technique for reducing the possibility of splitting would be to do a couple of normalising cycles. Take the whole thing up to a good red heat (after searching for some recommended temperatures from the obvious sources) then just let it air cool. Another tip would be to heat the quenching oil before you lob it in there.
Old leaf spring or any other mystery metal is going to be a law unto itself so may require a few test samples to nail it. Plus of course, an old leaf spring is going to bring a huge amount of stress to the party having spent years being a leaf spring!
h-dom
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Any time before I quench I do at least three normalising cycles, more if I have been forge welding. I made an axe which I have posted before which was exactly this combination, mild steel outer with leaf spring bit, it heat treated perfectly but I did only do an edge quench.
Not so sure about preheating the oil, my understanding is this gives a faster quench and in this case effectively I would be better with a slower quench.
Anyway, been practising my forge welding again this morning, below is a billet I have made, only 7 layers and I'm not going for any kind of pattern, it's an old file mixed with some 01. Started with a stack 3" long and drawn out to 10" using the fly press, no hammering here.
I'll be going stock removal now and making a little blade from it hopefully if all the welds are good. They look it from the outside but who knows what I will find when I cut into it.
Screwdriver
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Yeah, I'm not sure either but my take is that while the overall cooling rate will be quicker (because the oil is less viscous) that is better for crack prevention since the "jacket" of mixed steels are rapidly cooled in unison and not just with a sudden shock to the "skin" and a much slower cooling through the material due to turbulence/vapour.
I just made that up but I am going to stick with it...
