Sharpening Secateurs

Hi there

I have invested in a sharpening stone and diamond file from Niwaki to keep my Niwaki secateurs in tip top condition however I am struggling to get the right angle.

I know it should be 23 degrees and am trying out on an old pair but can’t seem to get them as sharp as Niwaki pairs.

Any tips?

 

Japanese bypass secateurs have blades which are made from a tempered hardened steel which can hold an edge sharpened at that angle.

Does the trial pair have identical blades?

Also, apply pressure slow and evenly perpendicular to the blade edge and gradually slide accross.

Deburr the flat side of the blade on a plank of wood - similar to what you would do with a slit-throat razor blade on a leather strap.

 

I've never been able to sharpen any blade to the same sharpness as a new blade

 

Hi Darren i use Niwaki secateurs, I do not think any secateurs you buy in the uk will be as good or sharp as Niwaki they use a good grade carbon steel which is forged and hot laminated. I have paid a lot more for other brands which claim to be as good, i have never found any to match Niwaki which i have used for years.
regards Sandy

 

I know I've got the correct angle when I can feel resistance to the sharpening stone - use the stone and move the angle of the blade until you can feel resistance. This means that metal on the edge is being removed and the blade is sharpening. It takes some practice but once you've found the correct angle it's fairly straightforward.

If you've got a sharpening steel in the kitchen, try this approach first on your kitchen knives - to see how it works on a larger blade.

 

As a blacksmith and wood turner I´ve always used a sharpening stone, but since I started carving olive wood I have had to up my game. I have several blades, curved and straight and two hand axes to keep sharp enough to shave with. I use emery paper on a flat or round wooden stick, depending on the blade. Then a leather strop on a similar backing, with a good polishing compound. I´ll strop a blade several times before I need to use emery again.

I recommend you look at the many videos on YouTube regarding spoon carving where the whole business is revealed. That´s where I learned to blacken the edge with a felt tip pen, so I could see exactly where I was making contact, and many more useful hints.
Everyone finds sharpening difficult, but it´s a very satisfying feeling when the edge dulls, the wood begins to tear, and you know that with a bit of stropping you can get the blade slicing through the wood again.

 

Anyone got suggestions on the best tool to sharpen secateurs please?

 

It is presumed that you have bypass secateurs, for the anvil type are a simple blade as a knife and a flat anvil.
Bypass secateurs are 'hollow ground', as are scissors, on a large *diameter grindstone, which is not normally within the capacity of home workshops. However some 'improvement ' can be effected using a shaped stone stick , carborundum or diamond.
Specialist service is sometimes available through ironmongers (a rare beast these days. Most of us died of starvation...!) and certain manufacturers; this may not be cost effective.
*600mm upwards

 

I bought a Felco sharpening stone which I think is pretty good. It was recommended to me by a fellow professional gardener in the area and he used it on his hedging shears too.

 

Interesting to hear that as I have had a few pairs over the years and none of them have been hollow ground, just a flat face cutting against another flat face, the curved side, albeit just thin and often cut back .
Is that the side you are referring to as hollow ground?
I usually just sharpen the cutting blade and I've never done anything to that side.
If that makes any sense.

 

I also use a Felco sharpener on my bypass secateurs. This may help @GreenFingeredPete :

 

I can never get my secateurs to sharpen up as good as new. Experience has shown me that I'm best to invest in two pairs of a "middle of the road" secateurs, so I can swap to the second pair when the first becomes duff, then pay to replace them.
I then donate the duff ones to a charity called TWAM, (Tools with a Mission), who can sharpen them, then send them for use around the world, to people who cannot afford to buy them.

 

The perceived wisdom is that a hollow ground edge remains sharper, the edge persists as it is a stronger edge and the hollow gives clearance as it meets the respective lower jaw.
Cutlery blades should always be drop forged rather than stamped; this creates a metallurgical strength that enables a persistent long lasting sharp edge. This is thought best performed in carbon 40 steel, but which is more prone to oxidation (rust) than nickel/chromium steels sometimes used; for they have 'magpie' appeal "cos they are all shiney".
The cheaper processes may be applied to budget tools; this seperates these from the top end products such as the classic Felco range or the much missed Wilkinson Sword (Prior to their sellout to Fiskars c1988)

 

What effect does tempering have, rather than the type of steel used, I have had various chisels over the years, some brittle some not so, as in paring chisels which are longer and more likely to break.
Older ones were always more likely to rust than modern ones.

Some were easier to get a good edge on, others not so easy.

I remember some being stamped, cast steel, they were usually older ones.

 

Now you're taking me off- topic !
As simply as I can explain, the process of smelting affects the chemical composition of a metal, by including minor ingedients, to create an alloy.
Purity. Some additional metals alter the properties, beit molecular chain, ductility, mallability, hardness , corrosion resistance etc. Differing mechanical processes alter the crystalline structure and grain size.
Cast materials tend to be granular whereas forged (hammered) become more dense and lend themselves to upsetting, stretching and rolling which increases linear molecular chains- stronger in some dimensions.
Casting is a cheaper process than forging, in simple terms
Tempering is a post formed process to alter (improve ) surface hardness and/or toughness, by quenching for example, or nitriding with a metallic salt. It would be used on forgings whereas castings may be annealed to remove inherrent stresses.

Blacksmithing is a 5 year apprenticeship, for good reason !