SDS chisels - sharpening
The Medway Handyman
They don't seem especially 'sharp' from new, but I guess this is not
required for masonry. After a short time they become blunt objects & I
sharpen them with an angle grinder.
Is there a specific degree of 'sharpness' required for masonry use?
Second question, I frequently come across tree roots that need cutting. How
would I sharpen a wide SDS chisel to cut through?
I can grind the edge to a very sharp edge, but do I need to harden them in
any way? Quenching & stuff?
--
Dave - The Medway Handyman
www.medwayhandyman.co.uk
John Rumm
> They don't seem especially 'sharp' from new, but I guess this is not
> required for masonry. After a short time they become blunt objects & I
> sharpen them with an angle grinder.
Prefer a bench grinder myself, but I am sure the angle grinder does the
job nicely... Try not to overheat the end (of you or the chisel! ;-))
> Is there a specific degree of 'sharpness' required for masonry use?
I usually copy the original angle - about 45 degrees each side (i.e. the
point being about 90 degrees).
> Second question, I frequently come across tree roots that need cutting. How
> would I sharpen a wide SDS chisel to cut through?
Perhaps buying a SDS wood cutting chisel would be a better starting
point - I would guess they will tend to have more temper than the normal
masonry ones.
(a green wood blade in a reciprocating saw works a treat on roots)
> I can grind the edge to a very sharp edge, but do I need to harden them in
> any way? Quenching & stuff?
Not my area of expertise...
--
Cheers,
John.
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meow...@care2.com
> Couple of questions re SDS chisels.
> They don't seem especially 'sharp' from new, but I guess this is not
> required for masonry. After a short time they become blunt objects & I
> sharpen them with an angle grinder.
>
> Is there a specific degree of 'sharpness' required for masonry use?
>
> Second question, I frequently come across tree roots that need cutting. How
> would I sharpen a wide SDS chisel to cut through?
>
> I can grind the edge to a very sharp edge, but do I need to harden them in
> any way? Quenching & stuff?
they're already hardened & tempered. Take care not to get it too
hot when grinding and no need to do anything.
NT
Bob Minchin
> Couple of questions re SDS chisels.
>
> They don't seem especially 'sharp' from new, but I guess this is not
> required for masonry. After a short time they become blunt objects & I
> sharpen them with an angle grinder.
>
> Is there a specific degree of 'sharpness' required for masonry use?
>
> Second question, I frequently come across tree roots that need cutting. How
> would I sharpen a wide SDS chisel to cut through?
>
> I can grind the edge to a very sharp edge, but do I need to harden them in
> any way? Quenching & stuff?
>
>
Take care when sharpening not to get them too hot as this will draw the
temper and soften them a bit.
Don't sharpen them to too much of an acute angle. This will give a weak
edge that will blunt quickly.
You DO want an acute angle and a razor sharp edge for tree roots but
this is not really the right tool for that job. If you must SDS a tree
root then buy and adapt a chisel for that job alone.
hth
Bob
newshound
"Bob Minchin" <nos...@falseaddress.com> wrote in message
news:lvd_j.8786$Ht....@newsfe05.ams2...
The screwfix SDS wood chisel goes through roots like a knive through butter,
also for extracting old oak lintels. I had a chisel shank fail in fatigue
during one particularly brutal job (but they are cheap considering the time
they save).
Andy Dingley
<davidl...@nospamblueyonder.co.uk> wrote:
> Is there a specific degree of 'sharpness' required for masonry use?
They're not strictly chisels, as they don't form a cut chip. What they
do instead is to concentrate the force into a small area so that the
stone "crumbles" You need a narrow edge, you don't need anything
remotely sharp. Unless they've started to turn back into a burr, you
don't need to even try sharpening them.
> Second question, I frequently come across tree roots that need cutting. How
> would I sharpen a wide SDS chisel to cut through?
Buy some SDS wood chisels (Bosch do a set) Different shape, different
temper.