How does LN sharpen at factory?

[Craig Regan]

Does anyone know what methods Lie Nielson uses to sharpen their blades? Do the workers use the LN honing guide? Their blades are so perfect, it makes wonder...

[Jim Koepke]

Does anyone know what methods Lie Nielson uses to sharpen their blades? Do the workers use the LN honing guide? Their blades are so perfect, it makes wonder...

My first question would be whether they are hollow ground or do they come with a flat bevel?

If they are hollow ground that would indicate they do not use a honing guide for at least part of the process.

When it comes to finish honing they likely have something set up for speed of production.

Maybe someone who has taken a shop tour will chime in.

jtk

[Craig Regan]

Might be inefficient for a factory worker to use little honing guides on a production line?

[Mike Brady]

My impression from the Lie-Nielsen blades that I have is that the blades themselves are completely the product of CNC machinery, with the exception of a final step where some polishing of the blade back appears to have taken place. The result is a blade that could be used out-of-the-box ; but requires some polishing of the bevel (or establishing a secondary bevel, in my case) to delivery peak results. My Lie-Nielsen tools date back a bit, so I can't honestly speak of current production. The last time I was at the factory the presense of CNC machinery was very impressive. Clearly it is devoted to production since nothing new has sprung from the loins of Lie-Nielsen in quite a while.

[Tom Blank]

I have purchased both LN bevel up and bevel down replacement blades in the last year or so and both were flat ground. Nicely done too.

A few years back I called in to see what grit wheels they recommended for an 8" slow speed bench grinder when regrinding a primary bevel. The answer: don't use a grinder, do it by hand.

TAB

[Rob Luter]

I'm planning on being up there for the open house this year. Hoping I can get a peek at the process and report back.

[Craig Regan]

Also, Veritas? Their blades are nice out of the box. Maybe they have a production method that could be helpful to some of us?

[David Bassett]

Also, Veritas? Their blades are nice out of the box. Maybe they have a production method that could be helpful to some of us?

It's been previously reported LV surface grinds the backs of the Veritas irons. I can't imagine they don't also have an automated way to grind the bevel. (I don't think LN is as big, but I've got to believe they're big enough they too use at least semi-automated processes.)

I also can't imagine there's much involved in grinding dozens, perhaps hundreds, of irons every day that scales to a hobbyist who needs to regrind a profile infrequently. (When making a significant change or after a drop or unfortunate collision, e.g. with a knot, a nail, or a planing stop.) Small knife makers, with much lower volume than LV or LN, seem to rely on belt grinders. I'm not sure even that is practical equipment for a hobbyist woodworker.

[Doug Dawson]

It's been previously reported LV surface grinds the backs of the Veritas irons. I can't imagine they don't also have an automated way to grind the bevel. (I don't think LN is as big, but I've got to believe they're big enough they too use at least semi-automated processes.)

I also can't imagine there's much involved in grinding dozens, perhaps hundreds, of irons every day that scales to a hobbyist who needs to regrind a profile infrequently. (When making a significant change or after a drop or unfortunate collision, e.g. with a knot, a nail, or a planing stop.) Small knife makers, with much lower volume than LV or LN, seem to rely on belt grinders. I'm not sure even that is practical equipment for a hobbyist woodworker.

There's a LN factory shop tour on Youtube somewhere, which covers some of their sharpening IIRC. I seem to recall a belt grinder being used.

[Derek Cohen]

I visited the LV factory in 2013 and observed the special rotary grinders preparing the backs of the blades. They end up exceptionally flat, and the bevels are prepared with to an equivalence of 4000 grit. It should take seconds to polish to 8000 grit.

Regards from Perth

Derek

[lowell holmes]

Check this site. They really work well if you use a diamond hone.

https://www.lie-nielsen.com/products/honing-guide-bladesstandard

[Jim Koepke]

Check this site. They really work well if you use a diamond hone.

https://www.lie-nielsen.com/products/honing-guide-bladesstandard

Would you want to hone hundreds of blades every day using one of those?

Back in my days of buying a lot of rusty blades 10 or 15 blades was enough to make me want to do something else for a while. This was with the Veritas Mk.II Power Sharpening System (https://www.leevalley.com/en-us/shop/tools/sharpening/power-systems/48435-veritas-mk-ii-power-sharpening-system) and five blade holders. With five blade holders when the blade got hot, it could be set aside. After working four more blades the first one would be cool enough to put back to the grinder.

jtk

[lowell holmes]

No I would not. :)

Here is a low price version of one.

https://www.amazon.com/s?k=honing+guide&hvadid=77859219277124&hvbmt=be&hvdev=c&hvqmt=e&tag=mh0b-20&ref=pd_sl_3rivnxqcxb_e

Actually, I sharpen on diamond hones and it is not that difficult.

[Jack Frederick]

I never did the shop tour, but Maine was my biggest market for heating equipment for the 25 yrs I lived in New England. It really isn't fair how they treat you at LN. You walk into the show room and ALL of the tools are hung on the wall or sitting on the benches with assorted pieces of wood to choose from. They greet you at the door and then they leave you alone with all the tools, the wood. I got so I wouldn't take the Coast Road so I didn't have to drive by the place. it just isn't fair the way they treat you. Maine is great country and Mainers are the best. Rob, you will have a great time downeast.
I can't imagine that the blades aren't CNC'd. I follow their instructions for sharpening and a new blade takes very little to get ready to go. They do require honing. All the years I've had them only last year did I finally buy their Honing Guide. My blades and therefore my work are much better with it.

[Tony Zaffuto]

I own a powder metal parts manufacturing plant, and one of our products are high precision washers. We make between 26 and 28 million of these per year, and all are precision ground to within .0004" total tolerance range, including parallelism. They are done on three double disc grinders, with a finish at least equal to the back of any factory plane blade I've seen.

I doubt that any modern plane maker is doing that many blades, so here are my two cents: First, I would guess that each blade is roughed out with a partial bevel, and through hole, prior to heat treating. After heat treating, I would suspect the blades are then ground, both sides. After this grinding, I would guess the bevel honing occurs in a gang fixture on a surface grinder, and possibly a second bevel honing, again in a gang fixture, with a very fine wheel. Bevel grinding would probably occur with some sort of air cooling (for some of our operations, we use compressed air as a coolant), so as to prevent rust.

I doubt any linishing is done on the blades, mainly because the fineness of grit required would be extremely difficult to control over heating on the bevel. Equipment does not have to be ultra high tech CNC for these operations, but it absolutely does need to be tight to hold tolerances.

[Mike Brady]

Tony is not only well-informed, but also most likely correct. The Lie-Nielsen irons are very nicely machined, but look exactly as he describes.

[Bob Jones 5443]

Not sure if the resolution will be high enough to read the fine print, but here is a photo I took at a recent Lie-Nielsen Hand Tool Event describing the creation of their plane irons. I hope this adds to the conversation.

421956

[Tony Zaffuto]

Not sure if the resolution will be high enough to read the fine print, but here is a photo I took at a recent Lie-Nielsen Hand Tool Event describing the creation of their plane irons. I hope this adds to the conversation.

421956

Had to put several pairs of reading glasses on, but pretty similar to what I posted yesterday, though a bit more labor intensive with the individual bevel work.

[Mike Brady]

Very helpful. Looks as if there is a honing step by hand to refine the bevel, although most purchasers will go to their stones or whatever to get a cutting edge. I liked the answer from LN about (re-)grinding: "don't do it"