Can't get sharpening angle right

[Tim Booher]

All, I'm struggling to learn to sharpen my chisels.

I purchased GREBSTK 4PCS Professional Wood Chisel Tool Sets Sturdy Chrome Vanadium Steel Chisel, 1/4 inch,1/2 inch,3/4 inch,1 inch which are supposed to have a Sharpening angle of 25 degrees.

I have tried everything from wet stones, to diamond plates and now trying the scary sharp float glass + sandpaper solution.

I have a sled that allows me to set the angle accurately. I set that to 25 degrees, but only the very back top the chisel blade is making contact.

https://www.dropbox.com/s/7mrfhpp939lxl2x/2023-05-17%2011.21.00.jpg?dl=0

I increased the angle to 30 deg and that helped a bit, but I'm nervous to get off the factory spec.

How do I get the front of the blade to contact? I know I could keep sharpening for a _long_ time and the chisel would eventually sharpen at that angle.

Thanks for any help.

Tim

[Thomas McCurnin]

1. Put it on a wheel, like a Rikon, and grind it to the proper angle; or

2. Match the existing angle, whatever that is. Use an angle finder or one of those small brass circular notched angled finders to figure out the existing angle; or

3. If you are using scary sharp, try some 80g paper; or

4. Make a wood jig that looks like a a drawer handle to bridge a belt sander and rough sand the chisel to something equivalent to 25 degrees.

[Tim Booher]

so I could find the angle -- but it seems like I should just grind it to the right angle and work with that.

[Patrick Varley]

All, I'm struggling to learn to sharpen my chisels.

I purchased GREBSTK 4PCS Professional Wood Chisel Tool Sets Sturdy Chrome Vanadium Steel Chisel, 1/4 inch,1/2 inch,3/4 inch,1 inch which are supposed to have a Sharpening angle of 25 degrees.


I have tried everything from wet stones, to diamond plates and now trying the scary sharp float glass + sandpaper solution.

I have a sled that allows me to set the angle accurately. I set that to 25 degrees, but only the very back top the chisel blade is making contact.

https://www.dropbox.com/s/7mrfhpp939lxl2x/2023-05-17%2011.21.00.jpg?dl=0

I increased the angle to 30 deg and that helped a bit, but I'm nervous to get off the factory spec.

How do I get the front of the blade to contact? I know I could keep sharpening for a _long_ time and the chisel would eventually sharpen at that angle.

Thanks for any help.

Tim

https://youtu.be/GN4yr7vp4I4

I'd recommend watching some additional videos on sharpening. There are a million. But one key is understanding the idea of "primary" and "secondary" bevel. The factory bevel is probably somewhere around 25 degrees (though the exact number isn't necessarily important). The secondary bevel is what actually does the cutting (and more specifically, the edge between the secondary bevel and the back, both of which need to be flat, is what does the cutting), and many people will set that around 30 degrees.

If you don't use a secondary bevel, then yes, you have to get the whole primary bevel honed evenly. Not just on setup, but every time you sharpen. That's why the secondary bevel is helpful, as you only have to hone the first few millimeters of the blade. If you set it up this way, then you'll only have to regrind the primary bevel if you damage/chip the edge significantly and have to grind back the tip to repair it.

[roger wiegand]

Start on a powered grinder or sander to set the starting angle (a slightly concave cut will make your hand sharpening easier as only the front and back edges of the bevel will contact the stone. Yes, you just need to remove enough material to establish the primary bevel. It will take a long time by hand, be pretty quick on the grinder. Once that's done resharpening will be fairly quick work.

Only some chrome vanadium steels are high speed steels with heat resistance sufficient to turn red without losing temper so I'd treat them as if they are not, keeping them cool enough during grinding to avoid bluing of the edge.

A jig like the Veritas one makes keeping a constant angle much easier when hand sharpening.

[Dave VanDewerker]

The chisel looks to be a hollow grind, ground on a wheel. When you then sharpen the chisel on a flat stone the edge will only contact the stone at the top and the bottom. The chisel is sharp in your pic, just use it, the cutting edge is only where the two surfaces meet, not all the way up the slope. After you use the chisel and sharpen it a few time the two contact points will get closer and closer until they meet and you have a flat surface, that will not make the chisel any sharper.

[Edward Weber]

I have a sled that allows me to set the angle accurately. I set that to 25 degrees, but only the very back top the chisel blade is making contact.

https://www.dropbox.com/s/7mrfhpp939lxl2x/2023-05-17%2011.21.00.jpg?dl=0

I increased the angle to 30 deg and that helped a bit, but I'm nervous to get off the factory spec.

How do I get the front of the blade to contact? I know I could keep sharpening for a _long_ time and the chisel would eventually sharpen at that angle.

Thanks for any help.

Tim

Yes, the top of the bevel will be the only part touching until you grind enough away to get down to 25 degrees, then the front of the blade will be making contact,
Keep in mind, you're lowering the angle, you have to remove some material to get there.
Don't worry about the factory specs, they're your chisels, sharpen them to what ever angle works for you.
As others have said, maybe take it to a grinder to remove the bulk before using your sled or sharpening system of choice.

[George Yetka]

Using a jig, I think, you will have to extend it every so often as you cut through the old bevel or your angle will get steeper as you go.
I never had to establish a new primary bevel before

I used the jig my first 2 times but then switched to doing it freehand on water stones.

[Bill Dufour]

If the tool has water on it you are in no danger of overheating the steel. Very slight chance of overheating just the tip if you get too aggressive. If the working edge stops steamimg it is dry, quench in water and continue.
Rock cutting grinders sit a pan of water with a sponge touching the underside of the wheel.
Bill D

[Richard Coers]

Get a good grinder set up and it will only take 3 minutes to grind and then less than 3 minutes on grinding stones.

[Derek Cohen]

All, I'm struggling to learn to sharpen my chisels.

I purchased GREBSTK 4PCS Professional Wood Chisel Tool Sets Sturdy Chrome Vanadium Steel Chisel, 1/4 inch,1/2 inch,3/4 inch,1 inch which are supposed to have a Sharpening angle of 25 degrees.

I have tried everything from wet stones, to diamond plates and now trying the scary sharp float glass + sandpaper solution.

I have a sled that allows me to set the angle accurately. I set that to 25 degrees, but only the very back top the chisel blade is making contact.

https://www.dropbox.com/s/7mrfhpp939lxl2x/2023-05-17%2011.21.00.jpg?dl=0

I increased the angle to 30 deg and that helped a bit, but I'm nervous to get off the factory spec.

How do I get the front of the blade to contact? I know I could keep sharpening for a _long_ time and the chisel would eventually sharpen at that angle.

Thanks for any help.

Tim

Tim, even the best new chisels arrive as a kit. In addition to preparing the primary bevel and then sharpening the edge, you also need to ensure that the back of the blade is coplanar (it must not have high spots) and the back of the bevel is polished (1” is enough).

Further, if you plan to use a mallet or hammer to strike the handle, the blade edge needs to be tough enough to handle the forces on it. This translates into a bevel of 30-35 degrees. 25 degrees is too low. It will chip or fold.

With chrome vanadium steel, which is hardened by the addition of chrome, you need a strategy to sharpen. You cannot hone the full face - it will be arduous. Either you hollow grind the face (my preference, but I freehand blades) or you use a honing guide to create a small secondary bevel. I am not sure what you mean by “sled”.

If the heel of the bevel is touching, either the original bevel is not 25 degrees, or the guided angle is lower than 25 degrees. In any event, you want 30 degrees. Look up “secondary bevel”. Search for honing guides (Veritas offer a few types) and an “angle setting board”.

Regards from Perth

Derek

[Radu Tenenbaum]

First, I would measure the chisel angle with an angle finder. Just because the vendor says it's 25 Deg, that doesn't necessarily make it so. If the chisel is on spec, then check your sharpening guide. Is it really 25 Deg?

[Jim Koepke]

I increased the angle to 30 deg and that helped a bit, but I'm nervous to get off the factory spec.


so I could find the angle -- but it seems like I should just grind it to the right angle and work with that.

Tim, don't worry about the factory spec.

Don't worry about the "right angle."

There is no "correct angle."

It might help if you included your location in your profile. You may live near another member who would be willing to help you in person.

My chisels are set up at at a few different angles. (surely some here think me a nut case)

For paring, a shallow angle, 15-20º, works well for me. It is also likely to need refreshing more often.

For chopping 30º works fine.

Most of my chisels have a single bevel. My mortise chisels may have a secondary bevel.

Many have suggested using equipment you may not have.

Don't run out and buy something just yet.

One way to use what you currently have is instead of trying to set the chisel to a particular angle try setting it to the angle it already has.

I've done this by using a flat surface and holding the chisel's bevel flat on the surface. Then positioning the guide (sled holder whatever) to hold the chisel at that angle.

The goal is to remove as little metal as needed to get a sharp edge.

Later when you have more experience you can work on getting exact angles or regrinding the angle.

jtk

[Reed Gray]

My 'practice' set of chisels from years ago were the blue Marples chisels. They came with a carpenter's bevel on them, close to 40 or 45 degrees, so very blunt. I did grind them down to 25 for the primary bevel and then 30 for the secondary bevel. That greatly improved the cutting ability. My guess is that the present angle on your chisels is more the carpenter's bevel, and not the fine woodworking bevel. Not sure if you can measure the present angle or not. A grinder can be a huge help in establishing the primary bevel. After that, maintaining that primary bevel is much more simple. You can do that all by hand, but you will need a lot of time and elbow grease....

robo hippy

[Edward Weber]

Tim, don't worry about the factory spec.

Don't worry about the "right angle."

There is no "correct angle."

It might help if you included your location in your profile. You may live near another member who would be willing to help you in person.

My chisels are set up at at a few different angles. (surely some here think me a nut case)

For paring, a shallow angle, 15-20º, works well for me. It is also likely to need refreshing more often.

For chopping 30º works fine.

Most of my chisels have a single bevel. My mortise chisels may have a secondary bevel.

Many have suggested using equipment you may not have.

Don't run out and buy something just yet.

One way to use what you currently have is instead of trying to set the chisel to a particular angle try setting it to the angle it already has.

I've done this by using a flat surface and holding the chisel's bevel flat on the surface. Then positioning the guide (sled holder whatever) to hold the chisel at that angle.

The goal is to remove as little metal as needed to get a sharp edge.

Later when you have more experience you can work on getting exact angles or regrinding the angle.

jtk
I totally agree and put myself in the same camp. 20 for paring, 25 for general and 30 for chopping or repeated striking.
Different chisels and their uses require different cutting angles to be the most efficient.

[Jim Koepke]

I totally agree and put myself in the same camp. 20 for paring, 25 for general and 30 for chopping or repeated striking.
Different chisels and their uses require different cutting angles to be the most efficient.

There are three chisels in my kit that are for a specialized use. They are ground at 90º. They work kind of like a one toothed float.

jtk

[Rafael Herrera]

I wouldn't take the chisels to the grinder, try to determine what angle it came from the factory. If it's close to 25 degrees, just use whatever that angle is.

If you are using sandpaper, try 80 or 120 grit to aggressively reset the bevel angle with a guide. Try not to burn your fingers.

Two or three degrees plus or minus off of 25° is not a big deal. Focus on getting the back flat (1/4", 1/2" something like that) and can raise a burr when working the other side.

[David Carroll]

If you are going to use the sled regularly, and if you feel confident that you can repeatedly set it up the same way, accurately, then I would set it at 25-degrees on your sled and grind away until you regrind the entire bevel. Your angle will wind up somewhat less than 25-degrees, but no matter. There's no magic to 25-degrees, it's just a reasonable compromise between a very shallow and sharp 20-degree bevel and a more obtuse and sturdy 30-degree bevel.

DC

[Robert Hazelwood]

It's kind of silly for the manufacturer to state a specific sharpening angle. It depends on the use, the users technique, and the properties of the steel. Could be anywhere from 15 to 40 degrees, but most often between 30 and 35 for me.

Anyways you need to figure out what the current angle is. Use a protractor or slowly increase the angle of your jig until you start to get contact at the cutting edge. You might find the factory grind is too obtuse to be usable- sadly its not uncommon. I wouldn't want the primary bevel to be over 30 degrees in any case. If it is, you'll need to remove quite a bit of material off of the bevel.

If you don't have a grinder, the way I suggest to do this is to get a decent length of coarse sandpaper (60 to 100 grit) and stick it on a hard flat surface - could be a table saw top or jointer table, cutting board, etc. It doesn't need to be perfectly flat for working the bevel side. Use a honing guide set for something a bit less than you want your final sharpening angle to be- I recommend 20 to 25 degrees - and grind away using long strokes. This will go much quicker than using diamond plates, and will keep your plates from wearing out too quickly.

Keep grinding and checking the new flat surface you're creating at the top of the bevel. Check that you are not grinding it at a skew - if you find that you are, compensate by applying pressure to the side with more metal remaining. Use the whole bit of sandpaper and change it every 5 minutes or so of grinding - it dulls quickly and will cut much slower than fresh paper. Once the flat reaches the edge you are done with grinding. Now you can reset your guide for your actual sharpening angle (I recommend 30 degrees to start) and take it to the stones. You should be able to raise a wire edge almost immediately.

You might also find that the back needs work as well. If its more than can be quickly honed out using your stones, then I suggest again using the coarse sandpaper. But take more care to find a flat surface- I like to use a granite surface plate. Small imported ones from Grizzly, Woodcraft, etc. are not too expensive and are nice to have around.

[Tom M King]

These make it easy to not only get the angle you want, but it's exactly repeatable every time. Back when I had helpers, I would hire illiterate people that no one else would hire. The last two, working together, could almost read a tape measure. They had no trouble sharpening chisels good enough to suit me, which is Really sharp.

[Jack Dover]

"Factory" "specs" are arbitrary. If a "factory" would have know a thing or two about chisels - they would make better chisels. You're getting one spot of contact precisely because it's arbitrary and because the "factory" didn't really grind it at 25˚ (assuming your jig is accurate). In general this is normal: scales don't match on different jigs, so what's marked as 25˚ on a grinder support might correspond to 28˚on a sharpening guide. So don't paint by numbers, but rather inspect the contact surface and adjust the jig until the bevel has 2 points of contact or when a point of contact is at the edge (depending on your preferences)

The brand you're mentioning is just an entry level tool with a lot of price engineering on it, sloppy grinding is a part of it. This is good and bad at the same time. Bad is because every chisel from the batch has it's own hardness and the range is wild. So you have to figure the grinding and honing angles at which a given chisel retains its edge for the most reasonable time. From the experience (I have several sets of these btw) the angle will be closer to 30˚ rather than to 25˚ and that every chisel will have another angle, but the good part is that you can experiment not worrying about destroying a good tool. E.g. you can try different bevel geometry, vary angles, etc. to better understand what do you want from a chisel.

Btw, "sharpening for a _long_ time" is better avoided, this is why there are grinders. A grinder removes the bulk of steel and establishes a primary angle which you then refine. Refining is really polishing, so if you don't want to spend a couple of weeks re-establishing a primary bevel on ANSI400, you have to grind it to an angle you think might work and only then hone. These chisels are also good for learning to grind - something you will have to master, because what you're doing is an operation that happens at least a couple a times on a given day. Therefore if you don't want to be just a walking tool grinder and if you're determined to make things out of the wood at some point - you have to figure how to get this process in under 3-5 mins per tool.

[Tim Booher]

Wow. What an incredible set of answers. I learned a lot and also got some really good, practical, advice. I'm eager to grind the chisel to 25 degrees, so I can make a nice 30 deg bevel in the back. Thanks.

[Gary Focht]

Wow. What an incredible set of answers. I learned a lot and also got some really good, practical, advice. I'm eager to grind the chisel to 25 degrees, so I can make a nice 30 deg bevel in the back. Thanks.

I may be misinterpreting your “30 deg bevel in the back,” but you do not want a back bevel. You want a secondary bevel of 30 degrees.

[Jim Koepke]

Wow. What an incredible set of answers. I learned a lot and also got some really good, practical, advice. I'm eager to grind the chisel to 25 degrees, so I can make a nice 30 deg bevel in the back. Thanks.


I may be misinterpreting your “30 deg bevel in the back,” but you do not want a back bevel. You want a secondary bevel of 30 degrees.

Yes, Gary is right.

Back flat, bevel only on the topside whether you want a flat (single) bevel or sharpen using a secondary bevel.

jtk

[Jack Dover]

Just making sure it was clear: the angle at the edge is what defines edge life and that the final edge is honed on the same side where the bevel is ground. A grind bevel has anything to do with edge longevity only if a honing angle matches the grinding angle.

This geometry was brought to my attention by David W. It's the only geometry that could work reliably in dreaded KD Douglas Fir and allow for some serviceable results. It's different from the "microbevel" because I haven't heard "microbevel" people advocating for a really low grinding angle, also their "micro" bevels aren't that "micro-", I keep seeing honed edges taking like half of a bevel. Or in other words two arbitrary angles don't make this geometry: the honed edge has to be as small as you can get it and a difference between angles must be considerable.

The "22˚grind and 30+˚ honing angle" actually was described in one of the Paul Hasluck's books. Hasluck was an editor, so individual chapters were written by various people. What's interesting that it seems to be the only book where Hasluck published anything on sharpening, other books just mention sharpening equipment, but doesn't utter a word on how to shape an edge. Except this one book, "The woodworking". The chapter is short and well worth the read, if only for flames and brimstone hurled at convex bevel people. It was written by somebody with initials J.D. (promise I have nothing to do with it, I was busy with something else at that time), who goes back to the "Work" magazine times, where Hasluck was an editor and J.D. wrote most articles on toolmaking, steels, etc. The chapter can be found in "Work" btw, it explains it in great details and even has a forces vector diagram, which is why exactly nobody read it ("there's no vectors in my timber!").

There's another advice of constantly maintaining a low grinding angle. I don't really want to drown you in details, because at this point it's more important to be able execute this accurately and neatly rather than figuring theory behind it. But if you're interested I could dig out this book.

[Jack Dover]

How do you make sure a chisel in a red jig stays square? I have a similar Veritas guide (not manufactured anymore) and I like it because it holds a chisel better than a side clamping jig, but setting and keeping it square to the edge is pretty much impossible.

[Tom M King]

The red jig doesn't hold anything square. I would never sharpen the narrow chisel in it with that jig, but just grabbed what was close at hand to show that any chisel can be set in any jig with them. That red jig is an old Record, and just has a ball for a roller. It works good for irons with short radiuses like Scrub plane irons, or 8 to 10 inch radius Jack plane irons. I have no idea when they stopped making it.

I don't think I own any jig, including the old ones that I rely on to keep the edge square. Even that Veritas jig, which is rarely used, keeps the cambered roller on it. I don't think it's been used since I made those setting jigs, and that was in 2015 or 16. I had a helper that could use it as it came when sharpening with oil stones if we were using a microbevel, but no microbevels since back then either. The picture is the day I stuck those jigs together back then. There is another now with 18 and 27 degree angles.

As far as grinding angle, for us it's just to get the bevel out of the way. I don't worry about, and have no idea what they are exactly-mostly just done by eye. My helpers could never sharpen anything by hand alone so we don't depend on a hollow grind to register on a stone. We hollow grind because the grinder has round wheels.

The edge bevel is what we use those setting jigs to get. There is nothing to fumble with or repeat exact setting on, so they are foolproof. We just sharpen flat bevels with no microbevels, so the edge bevel can take over as much of the ground bevel that it likes until there is edge damage. Only with edge damage will the cutter revisit a grinder.

My plane irons have not visited a grinder in years.

[David Carroll]

I've had the old clamp on top veritas sharpening jig since they were first introduced, mine has the old block with different angles, before they switched to the hex (or is it Octagonal) wheel design.

I struggled for years with the jig trying to keep chisels, particularly narrower ones square. I had a tendency to favor one side, which would cause the blade to drift and pivot toward the right (in the jig). Once I realized this, the cure was to sort of pretend the jig wasn't there and use a light touch.
I keep my eyes and my focus on the edge being ground, keeping it square with my body and hand positioning and letting the jig set only the angle of the bevel. It isn't a mindless activity it requires a fair bit of attention. Eventually I got the hang of it, and retrained my body to apply even pressure.

I bought the new(er) Mark II jig, but it had way too much gizmosity (in my opinion) and used it once, then sold it.

I rarely use the old jig nowadays. The only time I use it regularly is with my LN No. 9 which I use for shooting. That iron wants to be dead square and with a very shallow grind and microbevel.

Jack Dover: I now use a very shallow angle (less than 20-degrees) and a convex bevel on a lot of my bench and paring chisels. I've been experimenting with this for years now, and so far I am convinced that there is some value there, when freehand sharpening. If you do dig out the Hasluck book (which one?) to find the article by J.D. I'd be interested to read his criticism of the technique.

DC

[Jack Dover]

Can't find where the book can be found in its proper form, but this is one of versions that has most images removed for copyright purposes: https://www.google.com/books/edition/Working_with_Hand_Tools/HyyCDwAAQBAJ

The chapter you're looking for is titled "How Chisel Edges Should be Shaped". It's supposed to have several pictures, but only one has particular interest, where a diagram of forces is shown. The premise of the chapter is that there's a geometry providing the least resistance to the wedging action and there's a geometry that has the longes edge life, so these two can be combined for an operator's benefits.

I used to use this book as a reference, but this chapter was always skipped ('cos I assumed I can sharpen already). Then David W. pointed to it in an unrelated post, I tried it and I'm pleasantly surprised. Especially about a recommendation to grind often to maintain a low main bevel angle - apparently it's just one light touch of a grinder wheel in the bevel's heel area.

[John C Cox]

There are plenty of good sharpening videos online. If you don't have much equipment, sandpaper can be a good place to start. A quality coarse/medium combination carborundum stone and a fine india stone works well too.

In general, the process is:
Grind to establish the bevel and remove damage. This can be done via power units, very coarse stones, or sandpaper.
Hone to refine the bevel.

Lots of people love stones. I ended up power sharpening with a Worksharp unit and buffing the final edge.

[Andrew Pitonyak]

All, I'm struggling to learn to sharpen my chisels.

Tim,

If you live near the center of Ohio and would you like a sharpening buddy shoot me a message and we can whip those chisels into shape at the angle you prefer. You will end up with a hollow grind because that is what my equipment generates (I start with a Tormek).

Andrew Pitonyak

[Luke Dupont]

Generally, when I get a new tool, I put it to my coarsest stone, holding it at the angle that my hand is used to (a tad less than 30 degrees. Maybe 28-29).

That's the "correct angle" for me. I ignore the factory grind and just grind till I get to the edge.

Everything else from there is preference. Do you use a microbevel? Full flat? Convex? Concave? It doesn't matter. There is no correct, right or wrong way.

I tend to prefer the simplest way, which is a simple flat, sometimes everso slightly convex bevel all the way to the edge. No microbevels. It's not wrong and it works just fine on both Western and Eastern tools.

Don't fret over the details. It's only a problem if, when you go to use the tool, you find it to be a problem.

[John C Cox]

Chisels often need to be tested in your own work cycle and on the wood you are working to determine what sharpening angles hold up well

For example, are you chopping with a mallet/hammer or are you pushing through a cut? Are your cuts heavier or lighter? Are you working hard, dense wood (like rosewood/bubinga) or soft wood (like cedar?). Are you working dirty wood or wood that contains natural silica, or fairly clean wood without silica? Plywood is a good example, as it is not particularly "hard," but the combination of alternating grain layers, glue, and a lot of included grit puts a massive beating on tool edges.

Another consideration is that the "perfection" of edges honed to specific angles in jigs often results in a lower edge life than the same bevel honed by hand. This is due to the natural imperfection in human motion leading to slightly rounded angles at the apex, which are considerably more durable.

So... Don't obsess too much. Try sharpening with the stuff you have.

If you feel like you need a jig, Veritas makes a very good one. All jigs, including theirs, have a learning curve to getting things set up right. If you go this route, I would recommend using it to grind out chips and edge damage on a coarse stone or sandpaper, but freehand hone your final edge on your finest stones.

[James Talbert]

Wabash Valley Tool Sharpening can professionally sharpen your wood chisels correcting the primary angle from 20 to 35 degrees your choice depending on what you are using your chisels for. Your chisels will come back very sharp with a straight / square edge. It will then be up to you to finish if needed with your stones and polish. When sending wood chisels just let us know what angle you want on them. We charge $4 a chisel. Just google Wabash Valley Tool Sharpening for our website and shipping information.

[James Talbert]

Wabash Valley Tool Sharpening can professionally sharpen your wood chisels correcting the primary angle from 20 to 35 degrees your choice depending on what you are using your chisels for. Your chisels will come back very sharp with a straight / square edge. It will then be up to you to finish if needed with your stones and polish. When sending wood chisels just let us know what angle you want on them. We charge $4 a chisel. Just google Wabash Valley Tool Sharpening for our website and shipping information.