Router bits: 1/4" vs 8mm

[luvmytoolz]

It seems that it's really only Festool that is native to 8mm, here anyway.

Many smaller Virutex routers like the largish trimmer I bought come by default with an 8mm collet only, and the bigger tilting router came with 10mm and 12mm collets, 1 had to buy the 1/2" collet separately. The metric sizes seem to be more a European thing I've found. Although most of the Leigh dovetail bits come in 8mm too.

 

[Packard]

I have several routers.  My DeWalt gets a lot of use.  I have both a 1/4” and 1/2” collet for the DeWalt and also for my P-C 690.

A quick google search shows that 8mm collets and 1/2” to 8mm adapters are available for both.

I am unmotivated to make that change as I see no advantage in the 8mm shaft size.

For what it is worth, my Google search for the DeWalt is here:
https://www.google.com/search?q=8mm...router&ie=utf-8&oe=utf-8&client=firefox-b-1-m

 

[thudchkr]

...
The 8 mm is becoming (more) available in the Imperial lands. Where available, like in UK, it is actualy taking over.
  - 2x as strong as the "traditional" 1/4" and there is no wide availability of 5/16" to cover the middle ground

Don't know why I didn't think of this sooner. All we have to do to sell 8mm in the U.S. is quit calling it 8mm and call it 5/16". There's only .002" difference and there's no collet made that can't cover .002".  [big grin]

It is funny how all this stuff evolves. If I dug deep enough in my tool box, I'm pretty sure I could find some 3/8" shank router bits and a 3/8" x 1/2" adapter sleeve I used to use. I bet it would take a concerted effort to locate a 3/8" woodworking router bit for sale in the States today.

Funny thing is that the Standard bit set for the 2401 Keller Dovetail Jig uses 3/8" shank bits.  I ended up getting a 3/8" collet for my router so I wouldn't have to use the adapter sleeve they furnish with the jig package.

 

[Cheese]

I have several routers.  My DeWalt gets a lot of use.  I have both a 1/4” and 1/2” collet for the DeWalt and also for my P-C 690.

A quick google search shows that 8mm collets and 1/2” to 8mm adapters are available for both.

I am unmotivated to make that change as I see no advantage in the 8mm shaft size.

Router bushings & adapters are not a thing of beauty or joy...they just add additional total runout issues to the mix. If I had to make the decision of using a "naked" 1/4" diameter bit vs a 8 mm diameter bit with an adapter...I'd go with the "naked" 1/4" bit every time.

However, this discussion really centers around those routers that offer both 1/4" collets and 8 mm collets...and which way to go given the seemingly limited selection of 8 mm router bits. If that's the talking point, then it's 8 mm bits every time because of the significantly enhanced router bit shaft strength by a factor of 4x.
https://www.festoolownersgroup.com/...s/lee-valley-8mm-vs-whiteside-14-router-bits/

I was also a big supporter of 1/2" router bits when every router I owned used 1/2" diameter router bits (similar to that statement that everything looks like a nail when the only tool you own is a hammer), now...not so much.
Now, 1/2" Ø = big tough stuff, 1/4" Ø = small delicate stuff and 8 mm Ø = everything else between the 2 extremes. I wouldn't have made that statement 10 years ago though.  [smile]

 

[Cheese]

Funny thing is that the Standard bit set for the 2401 Keller Dovetail Jig uses 3/8" shank bits.  I ended up getting a 3/8" collet for my router so I wouldn't have to use the adapter sleeve they furnish with the jig package.

What is funny is that I believe that Milwaukee was one of the last manufacturers to offer 3/8" diameter collets for their routers and that was back in 1989...that was 35 years ago. I know because I owned one of those oddballs, a Milwaukee 5660. [smile]

[attachimg=1]

 

[Mini Me]

Not to mention how much quieter and smooth they are, and if its water cooled the dust extraction is so much better!

These days I tend to think of table mounted routers as ancient technology after using a spindle for so long. Noisy, limited speed control and marginal dust collection in most cases means I would never pick a router over a spindle.

 

[derekcohen]

Thanks for all the replies!

There are Famag bits from Germany, which may be the better quality than CMT, but appear quite expensive and require delivery from Germany. Still, good to know these options. It would be great if you, Jeff, get in on this size. It appears to be a significant gap in the market.

Arden are also known for being a decent Chinese producer. Their low price may bias some to think that they are less than they are ... but I suspect that they probably manufacture a lot of the bits sold by by others.

I do think that it is interesting that router users have not "discovered" 8mm bits to replace 1/4". At least, no one seems to be mentioning this, although several here have discovered their advantage. I have a large Elu 177e, which is a 1/2" machine. That is great for heavier stock removal. I also have a smaller Elu MOF97e, which has been used to date with 1/4" bits (it cannot use 1/2" bits). Now I want to use it with 8mm bits, and this could open up a new world, where the smaller, lighter router (it really is a beaut, although 20 years old) may be capable of most of which I previously used the 1/2" machine for. For much of the work we do outside a router table, do we need more than what the 8mm bit can offer?

Regards from Perth

Derek

 

[Packard]

Thanks for all the replies!

There are Famag bits from Germany, which may be the better quality than CMT, but appear quite expensive and require delivery from Germany. Still, good to know these options. It would be great if you, Jeff, get in on this size. It appears to be a significant gap in the market.

Arden are also known for being a decent Chinese producer. Their low price may bias some to think that they are less than they are ... but I suspect that they probably manufacture a lot of the bits sold by by others.

I do think that it is interesting that router users have not "discovered" 8mm bits to replace 1/4". At least, no one seems to be mentioning this, although several here have discovered their advantage. I have a large Elu 177e, which is a 1/2" machine. That is great for heavier stock removal. I also have a smaller Elu MOF97e, which has been used to date with 1/4" bits (it cannot use 1/2" bits). Now I want to use it with 8mm bits, and this could open up a new world, where the smaller, lighter router (it really is a beaut, although 20 years old) may be capable of most of which I previously used the 1/2" machine for. For much of the work we do outside a router table, do we need more than what the 8mm bit can offer?

Regards from Perth

Derek

None of which provides an overriding argument to switch.  (But this thread has been both interesting and entertaining.) [smile]

 

[jeffinsgf]

... Now I want to use it with 8mm bits, and this could open up a new world, where the smaller, lighter router (it really is a beaut, although 20 years old) may be capable of most of which I previously used the 1/2" machine for. For much of the work we do outside a router table, do we need more than what the 8mm bit can offer?

Regards from Perth

Derek

This is the application where I reach for the OF-1000 and use 8mm when I can.

 

[mino]

...
I do think that it is interesting that router users have not "discovered" 8mm bits to replace 1/4". At least, no one seems to be mentioning this, although several here have discovered their advantage. I have a large Elu 177e, which is a 1/2" machine. That is great for heavier stock removal. I also have a smaller Elu MOF97e, which has been used to date with 1/4" bits (it cannot use 1/2" bits). Now I want to use it with 8mm bits, and this could open up a new world, where the smaller, lighter router (it really is a beaut, although 20 years old) may be capable of most of which I previously used the 1/2" machine for. For much of the work we do outside a router table, do we need more than what the 8mm bit can offer?

...

I think you both raised the point and answered it well.

There is exactly zero technical reason to replace 1/4" bits one already possesses for tasks they work well for.

The "push" comes from the other side - replacing/avoiding the usage of a heavy 1/2" router (with a heavy strong shaft) and related bits for tasks where 1/4" does not cut it anymore but 8 mm still does. There are a lot of casual hand-routing tasks in this "zone". I would argue the majority of 1/2" uses in sheet goods cabinetry falls there.

 

[luvmytoolz]

Thanks for all the replies!

There are Famag bits from Germany, which may be the better quality than CMT, but appear quite expensive and require delivery from Germany. Still, good to know these options. It would be great if you, Jeff, get in on this size. It appears to be a significant gap in the market.

Arden are also known for being a decent Chinese producer. Their low price may bias some to think that they are less than they are ... but I suspect that they probably manufacture a lot of the bits sold by by others.

I do think that it is interesting that router users have not "discovered" 8mm bits to replace 1/4". At least, no one seems to be mentioning this, although several here have discovered their advantage. I have a large Elu 177e, which is a 1/2" machine. That is great for heavier stock removal. I also have a smaller Elu MOF97e, which has been used to date with 1/4" bits (it cannot use 1/2" bits). Now I want to use it with 8mm bits, and this could open up a new world, where the smaller, lighter router (it really is a beaut, although 20 years old) may be capable of most of which I previously used the 1/2" machine for. For much of the work we do outside a router table, do we need more than what the 8mm bit can offer?

Regards from Perth

Derek

For Australia specifically I'm not actually convinced the market for 8mm cutters is that great. We have cutters available generally in 1/4" and 1/2" across the full spectrum from ridiculously cheap via Asian suppliers, to incredibly expensive industry specific ones (that also for some reason seem to try and target hobbyists with) that tend to cater to most segments pretty comprehensively.

I think it would be a very hard sell to convince most people to spend on a single 8mm cutter the equivalent cost of one or two boxed sets of cutters for what is really a very niche product here, despite being superior to 1/4". I don't think the numbers would look at all attractive to suppliers. Especially if you also need to buy the collet to suit, for the 1400/2200 it's $140 or so.

 

[Packard]

Thanks for all the replies!

There are Famag bits from Germany, which may be the better quality than CMT, but appear quite expensive and require delivery from Germany. Still, good to know these options. It would be great if you, Jeff, get in on this size. It appears to be a significant gap in the market.

Arden are also known for being a decent Chinese producer. Their low price may bias some to think that they are less than they are ... but I suspect that they probably manufacture a lot of the bits sold by by others.

I do think that it is interesting that router users have not "discovered" 8mm bits to replace 1/4". At least, no one seems to be mentioning this, although several here have discovered their advantage. I have a large Elu 177e, which is a 1/2" machine. That is great for heavier stock removal. I also have a smaller Elu MOF97e, which has been used to date with 1/4" bits (it cannot use 1/2" bits). Now I want to use it with 8mm bits, and this could open up a new world, where the smaller, lighter router (it really is a beaut, although 20 years old) may be capable of most of which I previously used the 1/2" machine for. For much of the work we do outside a router table, do we need more than what the 8mm bit can offer?

Regards from Perth

Derek

For Australia specifically I'm not actually convinced the market for 8mm cutters is that great. We have cutters available generally in 1/4" and 1/2" across the full spectrum from ridiculously cheap via Asian suppliers, to incredibly expensive industry specific ones (that also for some reason seem to try and target hobbyists with) that tend to cater to most segments pretty comprehensively.

I think it would be a very hard sell to convince most people to spend on a single 8mm cutter the equivalent cost of one or two boxed sets of cutters for what is really a very niche product here, despite being superior to 1/4". I don't think the numbers would look at all attractive to suppliers. Especially if you also need to buy the collet to suit, for the 1400/2200 it's $140 or so.

The collet cost I see advertised for more popular routers runs from $25.00 and up.  Collet adapters are even cheaper.

But what would motivate me to invest in 8mm bits and collets?  I have both 1/2” and 1/4” collets and bits.

I have not seen anything that seems persuasive enough to jump ship.

 

[jeffinsgf]

The collet cost I see advertised for more popular routers runs from $25.00 and up.  Collet adapters are even cheaper.

But what would motivate me to invest in 8mm bits and collets?  I have both 1/2” and 1/4” collets and bits.

I have not seen anything that seems persuasive enough to jump ship.

On cuts that are at the upper limit of what 1/4" shank should do, the 8mm shank provides additional stability. Case in point is dovetail bits. A half-inch dovetail bit with 1/4" shank is a screamer in a dovetail jig. You can't overcome that by making multiple cuts...you have to cut to full depth in one pass or your dovetail is a Christmas tree. The same bit in 8mm is much stiffer, and vibrates far less, which means the dovetail cut is much more consistent.

Similarly, if you're rabbeting or grooving with a 1/4" shank, 1/2" diameter (or larger) straight bit, you have to take tiny bites to eliminate chatter. With an 8mm bit, you can take much deeper passes without chatter.

Nobody in this thread seems to be suggesting you throw out all your 1/4" bits and replace them with 8mm.  In fact, I don't think you could if you wanted to. At this point, there just isn't the variety of bits in 8mm to match 1/4".

What I'm doing is buying 8mm when the bit is available and the application makes it an advantage. Festool's bits are simply exceptional quality. I paid dearly for the 1.5mm radius replaceable blade round over bit. It is without question the smoothest round over bit I have ever used...and that's a lot of bits. The 4 edges on the inserts will more than likely outlive me. I've already forgotten what I paid for it. I remember it was expensive, but every time I use it I smile. So I don't care what I paid. Same with their dovetail bits. Their bits in a OF-1010 and a dovetail jig are fun and rewarding to use. It doesn't scream and chatter like a 1/4" bit in a 1-1/2HP Bosch, so that's what I use.

 

[Packard]

Whiteside is my preferred router bit source. 

I just looked, and it seems that they only have one (1) 8mm shaft bit. 

When Whiteside makes the change, I will consider it also.

I’ve also used Amana, CMT and Freud.  I think they are all about equal in quality. 

When I am looking for economy bits, I use “Roman” (made in China) brand for both forstner bits and router bits. They seem entirely satisfactory, though I only use them for infrequently used bits.  So I do not have a good feel for their durability.  But certainly a good value for less often used sizes or shapes.

As an aside: Freud has by far the nicest packaging.  Custom injection molded cases, especially nice for “sets”. But they seem like an extravagance.  They probably spend $50,000.00 for the molds on some of these.  So, an extravagance. 

Whiteside’s packaging uses blow molded and vacuum formed plastic packaging.  The cheap tooling is the selling point for those processes.  It does undermine the perception that Whiteside is a premium product. 

 

[Michael Kellough]

A 5/16” shank (8mm) is only 25% bigger than a 1/4” shank but has 50% more cross sectional area. A significant difference.

 

[mino]

A 5/16” shank (8mm) is only 25% bigger than a 1/4” shank but has 50% more cross sectional area. A significant difference.

.. and strength gets improved exactly twice: (8/6.35)^3=2.00 .. as it goes with the 3rd power of the cross section.

Similarly, 1/2" is 8x stronger than 1/4", which is a very big jump.

 

[Crazyraceguy]

Especially if you also need to buy the collet to suit, for the 1400/2200 it's $140 or so.

I don't know about the OF2200, but the 8mm collet comes with the OF1400 (in the US anyway)

Like Jeff said, I'm still fully on-board with 1/4" bits too. The 8mm comes into play above 1/4" cut diameter.

For me, the OF1010 truly hits the sweet-spot of a mid sized router. It feels far more robust in a lot of cases where I might have used a compact trimmer, and a unit in the 2hp+ range is simply over-kill.
Thus the 8mm bits, to fit that same range.

In the past, I would have purchased a 1/2" shank bit for most of those profiles, now some are 8mm instead.

 

[Packard]

I usually steer of generalized comments on “strength”, because there are so many factors involve.

Does that added strength mean that the torque will not twist off the shaft somewhere between the collet and the cutter?

Does it mean that everything remains on axis?

Does it mean you can stand twice as much weight on the shaft?

What does “twice as strong mean”.

I heard an argument saying that a 1/2” diameter wood dowel could support 500 pounds (if you could keep the dowel perfectly erect and could prevent it from bowing.  Wood has immense strength in axial-compressive loading.)

So, if my 1/4” shaft bit were to fail because it was not strong enough, how would that failure manifest itself?

 

[Michael Kellough]

[member=74278]Packard[/member] Jeff spelled it out above, “On cuts that are at the upper limit of what 1/4" shank should do, the 8mm shank provides additional stability. Case in point is dovetail bits. A half-inch dovetail bit with 1/4" shank is a screamer in a dovetail jig. You can't overcome that by making multiple cuts...you have to cut to full depth in one pass or your dovetail is a Christmas tree. The same bit in 8mm is much stiffer, and vibrates far less, which means the dovetail cut is much more consistent.”

 

[luvmytoolz]

Especially if you also need to buy the collet to suit, for the 1400/2200 it's $140 or so.

I don't know about the OF2200, but the 8mm collet comes with the OF1400 (in the US anyway)

On top of the higher cutter cost, here you'd have to actively search and pay extra for an 8mm collet option, I've had almost every brand router there is, and unless they've changed since, 8mm is not standard by any means except for the oddball Euro stuff I buy occasionally that's a direct import with the plug changed to our type. Some of the (grey market?) import Makita trimmer models come with an 8mm collet however I've found, but this is pretty much the exception.

And even for CNC spindles, the vast majority of machines in non-professional settings here would be 1.5kw or less, which means an ER11 collet and max shank of 7mm, so 1/8", 4mm, 6mm and 1/4" pretty much are the rule and are insanely cheap to buy. In a semi-full professional setting it's usually 2.2kw and above, so 1/2" shanks are generally the rule in my experience.