Sharpening Hedge Shears

[Fred Page]

I'm hopeless at sharpening garden hedge shears. Can somebody tell me the best sharpening angle? Should this be with a file or grindstone? I have never yet successfully sharpened shears and wonder where I'm missing out. If the two blades meet over the whole cutting length then is it ever necessary to flatten the 'flat' side?

 

[Harbo]

Mine take apart and I use a grindstone following the fairly steep existing angle (I've never measured it?)
Any burr on the flat side I've removed with a flat fine oilstone.
Years ago, one travelling sharpener that used to pound the streets, used a 4" angle grinder!

Rod

 

[bugbear]

I'm hopeless at sharpening garden hedge shears. Can somebody tell me the best sharpening angle? Should this be with a file or grindstone? I have never yet successfully sharpened shears and wonder where I'm missing out. If the two blades meet over the whole cutting length then is it ever necessary to flatten the 'flat' side?

Be very wary of working the flat side. Any bevel put here will prevent the cutting edges ever contacting each other (as they need to) again.

Most shears (it varies) have a very steep bevel (70-80 degrees) on the lower blade, and a lower bevel (50-60) on the upper. Take the blades apart (if at all possible) and simply file or grind depending on the hardness of the steel.

I find it (much) easier to clamp the blade so that the blade is at an angle, and the bevel is (now) horizontal. Leave a fine finish, otherwise the blades will catch on each other and raise burrs, instead of sliding over each other as they should.

BugBear

 

[Random Orbital Bob]

Dismantle, don't worry about the angle.

Take a black permanent marker pen and mark the bevel to be cut. Offer the edge up to the grinder (I use a bench grinder with a modifiable rest which I adjust to match the existing bevel). Without switching on, turn the wheel while in contact with the edge and then observe if the "clean spot" it creates has removed the marker pen right across the bevel. If it has your angle is correct, if it's only at top or bottom adjust till whole bevel marker is removed.

Grind at that angle then use whatever fine abrasive you have to remove the burr (wet n dry sandpaper, diamond file etc). Re-assemble, watch fingers!!

 

[DrPhill]

Simple. Thanks.

 

[dickm]

+1 for the 4" (actually, 4.5") angle grinder!

But maybe there should be a new thread on the correct angle for the bevel, single/double bevel, convex bevel - this could go on for weeks.

 

[AES]

............... and there's even a special angled accessory for the Dremel tool which, together with a small brown stone, works wonders VERY quickly when set to run at about 22,000 revs!!!! Dremel don't say what the angle is, but as someone else as said, it looks pretty steep - about 60 or 70 degrees at a guess.

And +1 for being careful with the FLAT back.

AES

 

[Random Orbital Bob]

The great beauty with the marker pen trick is you don't have to worry about the bevel angle. By using that method accurately you just map the existing factory grind (which you assume to be correct). The reason that makes sense is that different manufacturers grind their bevels at different angles and with shears they very rarely tell you what that angle is. In fact I cant remember any garden shears I've bought that came with a manual that published specs.

 

[bugbear]

The great beauty with the marker pen trick is you don't have to worry about the bevel angle. By using that method accurately you just map the existing factory grind (which you assume to be correct).

But (of course) if you or someone else has already sharpened the shears "freely", the factory grind angle is no longer there.

BugBear