As The Saw Blade Turns

[Knottscott]

Last November I posted a blade comparison chart of 30 various blades. This is an update to that list that's more user friendly. It includes at least 4 new blades, but more importantly, it includes separate charts for the general purpose, crosscut blades, and rip blades. In the initial chart all blades were rated the same way, which made it somewhere between difficult and useless to compare different types of blades. In the revised list, general purpose blades are grouped and compared to each other based on cut quality in various materials with different types of cuts, feedrate, and their ability to do many things well. The crosscut blades were judged more on cut performance and freedom from tearout than versatility or feedrate. Inversely, the bulk rippers were evaluated more on feedrate and ability to chomp through thick material than cut quality or versatility. The charts for each type of blade show the same parameters, but the emphasis changes for each, and the overall ratings were derived differently for each category because the criteria was different. It's possible to draw some conclusions of individual cutting characteristics across charts, but the "Overall Task Ratings" are only relevant within each of the three classification charts.

Disclaimer - This is by no means intended to be a scientific or comprehensive blade review. It's just some guy playing with saw blades in his garage on an average saw tuned by an amateur, and documenting some observations. Some of the ratings are just opinion and some are subject to several sources of variability, though I've tried to reduce those as much as possible and employ a logical method. There are undoubtedly flaws in my evaluation method as well as my approach to the documention. Even a slight change to the criteria and calculations impacts the results. Note that most of the blades are excellent performers for their respective tasks that I'd expect very good results from regardless of their relative ratings.

My saw is a 1-3/4hp hybrid, and I tend to favor good quality 3/32" thin kerf blades for the faster feedrate and lower strain on the motor. Faster feedrate gives me more control over the speed and the ability to handle thicker materials. Note that I've never had an issue with deflection with high quality TK blades, and the cut quality has been comparable to that of a full kerf blade...even without a stabilizer. I'll emphasize the importance of high quality with that statement. Some of you will prefer full kerfs for your own reasons, and if you've got a full 3hp+ cabinet saw, there's less reason to consider the TK's. Modern highend TK's have excellent alloys, construction, and precision. In every case when I compared a comparable high quality full kerf to a thin kerf, the TK had a noticeably faster feedrate, which inherently leads to lower burn rate and the ability to rip thicker stock with a smaller saw. The ratings reflect this and should be considered when comparing blades, especially if you have a saw with a larger motor.

One valuable lesson I've taken from experimenting with various blades, is that similar designs made to similar quality levels tend to have similar performance. The cuts from blades like the 40T WWII, TS2000, DW7657, and Gold Medal are nearly indistinguishable from each other, though feedrates vary due to kerf width. I'd expect similar cut performance from the similar Freud F410 or Infinity Super General. Provided that the initial quality level is at a high enough level, choosing the correct blade for the task makes more difference than brand, model, or price. Interestly, some of the best examples of the more value oriented blades aren't too far behind the top dogs. There are differences mind you, but the results from some of the better bargains leave acceptable cuts for most given applications. Don't confuse the "better bargains" with the cheap, low quality blades that are waste of money. There are some excellent $45 blades on the market that I consider to be bargains, but unfortunately, there are also alot of poorly made blades that cost too much regardless of price. The examples of poor performers that were included in this comparison were published primarily as a reference, and as a reminder of hard learned lesson that it's often more expensive in the long run to spend too little.

The charts and spreadsheets are posted below in 3 separate responses.

[Knottscott]

General Purpose/Combo Blades

GP/Combo blades:

This chart includes blades intended for general or multi purpose use. They typically range from 40 to 50 teeth, but there are a few exceptions. The Freud LU88 is listed as a 60T "crosscut" blade but it features a 15 degree hook that helps it rip well, thus it's very capable of GP type work. The Freud LU82 is a 60T TCG blade billed as multipurpose blade. And tbe 30T Forrest WWII is simply a lower tooth count GP blade with the same geometry as the 40T version. These blades are designed to be versatile and rip and crosscut well in alot of different materials. The have a very broad operating range, but tend to not excel in any one particular area. The better examples will give glue line cuts in the vast majority of situations, and are suitable for most circumstances. My ratings emphasized their versatility, feedrate, and cut quality. On the whole, the full kerf blades suffered slower feedrates on my saw....a non issue for saws with larger motors, but a reasonable concern for more modest saws. As you can see the differences between the top 5 are essentially numeric "decimal dust", and even the next 3 were merely victims of my weaker saw, and still have excellent cutting characteristics. Any of the top 14 are well suited for the task of general purpose use.




Individual comments:

The LU88 is a 60T ATB TK with a 15 degree hook and a Permashield coating. It quickly earned it's way toward the top of my list. True to it's categorization as a crosscut blade, it offers a very clean cut that's very low in tearout and swirl marks, and tends to be a better choice in sheetgoods and crosscuts compared to most general purpose blades. As mentioned earlier, it also rips very respectably with a good feedrate in materials up to ~ 6/4" without burning, making it an excellent lower cost choice for many applications. An excellent compliment to a good 24T ripper.

The 30T Forrest WWII has different strengths than the LU88, but is equally versatile and capable in a different range that leans toward thicker woods. It employs the same geometry as its more popular sibling, the 40T WWII, with an ATB grind, and 20 degree hook. This "GP" blade will hang with many of the 24T rippers in thick stock, while offering a significantly cleaner cut. The cut quality is remarkably close to the 40T and 50T GP blades. Since the cut quality of GP and combo blades is a compromise by design and not intended as a finished edge, IMHO the 30T WWII makes alot of sense as a primary blade and a beneficial alternative to the 40T WWII because of its wider operating range. This is about the closest you can get to a single blade that will do it all. An excellent compliment to an 80T Hi-ATB crosscut blade.

The 40T Forrest WWII is the industry gold standard by which most other GP/combo blades are measured. Versatile, clean cutting, very well made, and always a pleasure to use. You'll rarely encounter a situation where this blade is out of place.

The 50T Infinity Combomax proved to be the best overall 50 tooth combination blade I've tried to date. This is an extraordinarily well made blade that uses a unique ATB/R configuration that features a chamfered raker instead of the traditional flat top raker. It has very low tearout for this class of blade, and is particularly good in sheetgoods, while maintaining good ripping abilities due to it's 12 degree hook. Another top shelf well made blade that's a product of US engineering and Italian manufacturing.

The Ridge Carbide TS2000 proves to be every bit the equal of the vaunted 40T WWII, and is the closest in geometry and workmanship IMHO. Like the WWII, it's American made and is available in two kerf widths in the 10" diameter. It sports teeth that the manufacture claims are 35% thicker than their competition...a claim I can confirm to be true.

The Tenryu Gold Medal is another top shelf 40T GP blade made to world class Japanese standards. It's only available in one unique kerf width of 0.111", vs 0.98" for most TK's and 0.125" for most full kerfs. A very nice blade that suffered slightly slower feedrates than it's TK counterparts on my saw.

The DeWalt DW7657 is a relatively low cost dark horse in this group. At < $50, this British made precision GP blade offers similar geometry and performance as the WWII. Cutting performance was on par with the other top contenders. It too suffered slower feedrates than it's TK counterparts on my saw, but remains an excellent budget conscious choice for larger saws. Note that this blade was part of the DW series 60 line, but is now also available as the Delta 35-7657...often seen in the $40 range (or less!) A terrific bang for the buck in the full kerf GP class.

The Tenryu RS25550 is another relatively low cost top tier performer. This well made Asian blade features a fairly traditional 50T ATB/R combination configuration with a 15 degree rake, in a 0.126" full kerf width. It's about half the cost of it's more expensive "Gold Medal" sibling but offers well more than half the performance.

The LU86R010 40T TK is perhaps my favorite of the bargain blades. It's readily available shipped for ~ $35, with sale prices dipping into the $25 range. It has much in common with the higher tooth count LU88's geometry and features. It doesn't perform quite to same level as the LU88 and other $100 performers, but considering the entire class of GP and combo blades is a design compromise, it's hard to ask for more performance for the price, and not likely that you'll actually need more. An unsong hero for sure!

The German made Irwin Woodworker 50T combo by Leitz is essentially the same blade as the H.O. Schumacher & Sohn TK combo blade. It's not readily available anymore with the Irwin logo, but can be purchased under the Schumacher logo in the $65 range. It features a variable pitch teeth to reduce noise, in a 50T ATB/R configuration. A very good blade to be sure, but the other stellar performers make for some stout competition in this price range.

The Tenryu RS25540 is an Asian made 40T GP blade that offers an unusual tooth grind...an alternating top bevel alternating face (ATAF), with a 15 degree hook. The ATAF is an interesting approach that is essentially an ATB grind with alternating angled faces. It offers very good performance at the very low asking price of ~ $30 shipped from select dealers.

The Chinese made Leitz 40T is the stock blade that came on my 22124. Nice stock blade as stock blades go, but there's not much incentive to choose it over any of the other high performing low cost blades here.

The LU84R011 is traditional 50T combo blade in an ATB/R configuration, and perennial popular choice. This is the full kerf version, which like the other full kerfs, didn't feed fast enough for my liking. The performance is very good nonetheless, though not quite on par with the WWII and it's elite competitors. It's available as a TK in the LU83, which would likely be a better choice for me and others with typical home shop saws.

The Porter Cable Razor 100VT50 is a 50T ATB/R configuration with staggered teeth to help reduce noise. It doesn't shout high quality like the Infinity and Ridge Carbide do, but its available anywhere, costs ~ $30 and its performance is "good enough" for glueline rips and typical GP applications.

The LU82M010 from Freud's Industrial line is a departure from the design of most of the other GP and combo blades in this group. It's a 60T TCG configuration in a full kerf width. It's well made, but offers little over the impressive competition in this group, thought it's quite possible that the triple chip tooth grind will hold up better to hard use than the others, which would make it an excellent choice for laminates and manmade sheetgoods that are well known blade killers.

This Skil 36T full kerf GP blade had an unusual tooth grind that appeared to have a concave face. I didn't like it much, can't even recall the model number. The two TS blades I've used from Skil so far are the types of blades that prompted my search for higher quality and better performance. Move along...nothing to see here.

The 36T Delta Sidekick that came with my first Delta 36-600 TS is pretty much a waste of carbide and is a dent in Delta's armor. Even as newbie I could easily tell that it wasn't good enough.

[Knottscott]

Crosscut Blades

The same parameters were evaluated and charted for the crosscut blades, but the emphasis was placed more on cut quality and performance in sheetgoods than versatility and feedrate.

The 80 tooth blades appeared to clearly outperform the 60T blades at the task of crosscutting. Since the purpose of a dedicated crosscutter is typically to make an ultra clean cut in hardwoods or sheetgoods, I don't see much need for a 60 tooth version unless you need to crosscut very dense thick material that tends to be scorched by the 80 toothers.




The Freud F810 has since been replaced by the LU80R010. It's the same 80T full kerf Hi-ATB grind with a near zero degree hook, but now has a Permashield coating. This is simply the cleanest cutting blade I've tried to date. In fairness I don't spin a crosscutter very often and haven't tried the comparable models from companies like Forrest, Infinity, or Ridge Carbide. This model is also available as a TK in the LU79R010.

The DeWalt DW3218 is an 80T TK ATB design with a 5 degree positive hook. It also did a super job for me in those rare occurrences that I use a dedicated crosscut blade. It's nicely made and sports nice big teeth. The DW3218 is from DW's upper series 40, and is made in the UK. (Since B&D's purchase of Pentair (Delta and friends), it appears to me that the series 40 line has been revamped as the "Precision Trim" (PT), and now sports a yellow coating....I'm not positive that this is the case, but it appears the series 60 is becoming the Delta Industrial line.

The LU74R010 is an 80T TK ATB design with a slightly positive hook. It's basically the TK equivalent of the popular LU85. It also did a super job for me in those rare occurrences that I use a dedicated crosscut blade. Like other Freud Industrial blades, it's top quality and is made in Italy.

The DeWalt DW7647 is an 80T full kerf ATB configuration with a negative 5 degree hook. It's from DW's top series 60, which is morfing (or at least expanding) into the Delta Industrial line..the DW7647 is available as a Delta 35-7647. It's a nicely made blade from the UK, and did a superb job. The negative hook makes it especially void of tearout.

The German made Leitz Pro 80 has a similar geometry to the DW7647, but is a TK. It currently resides in my CMS for fine crosscuts but is equally adept at plywood and sheetgoods where an ultrafine edge is needed.

The Ridgid R1060C is made by Freud in Italy and appears to be made to similar standards as their Diablo and Avanti line. It's a 60T TK ATB configuration with a titanium coating and a positive 15 degree hook. The 1060 cuts cleanly and offers a more versatility than most of the other crosscutters, with better ripping ability than the others. It's configuration is similar to the LU88 that I listed in the GP chart. The kerf width is given as 0.090" which makes it the thinnest of all the TK's in this group...as stated earlier, I've never had a deflection issue but I wouldn't want to push it either. Nonetheless it's a really nice balde and a solid performer that's not outrageously priced. If you've got one enjoy, if you don't, I think one of the 80T choices would make a better dedicated crosscutter, and the 60T LU88 seems to overshadow this one a bit with tighter tolerances and bigger sharper teeth for about equal money.

The German made Leitz/Irwin 60T variable pitch ATB blade is not currently available under the Irwin name, but an identical blade can be found under the HO Schumacher & Sohn name. Cut quality was good, but this full kerf higher tooth count blade bogged too much for my taste on my saw. A better choice for a full 3hp saw if you need some ripping ability and a clean cut, but IMHO it doesn't outperform most of the better 40T and 50T blades that offer comparable cut quality and better ripping efficiency.

The DeWalt DW7646 is another very nice 60T ATB configuration with a midsize kerf of 0.118" (it's mislabeled as a full kerf in the chart). Like the Leitz/Irwin 60T, this is a fine blade that'd likely not see much action for the same reasons stated above...YMMV. It's also now available as a Delta 35-7646.

The Oldham 60T Industrial Finishing blade has to be one of the most disappointing blades I've used. I was new to woodworking when I shelled out $20 for what I thought would be a really nice highend "carbide" blade. It never did cut very well, fed slowly, wouldn't handle thick material well, and dulled way too soon. It could be argued that a rookie abused it, but I've abused a few dozen others in a similar fashion since. Spend the $20 on an enjoyable lunch instead.

[Knottscott]

Bulk Ripping Blades

The dedicated rippers were also subject to the same parameters as the other blades, but again the emphasis changed. This time feedrate and ripping efficiency were king, but with some consideration for cut quality, and versatility was heavily discounted. Even though I primarily spin a good GP or combo blade, I do frequently use a bulk ripper for heavy work. IMHO there should be at least one in every woodworker's inventory. They can spare your good blade from the bulk work, and tend to be kinder on your saw's motor. Since feedrate was a big factor, the kerf width also plays a bigger factor. The good TK's enjoyed a noticeable advantage in speed over the comparable full kerfs on my smallish saw. In my relatively limited experience with dedicated rippers, the 24 toothers seem to be the happy medium between bulk and acceptable cut quality. The cut quality on the better 24 tooth blades are just barely acceptable for a glue joint, and definitely fall short on an exposed edge.




The German made Leitz/Irwin 24T variable pitch FTG TK is usually my "go to" ripper. As bulk rippers go, it's got what I want...an excellent feedrate, reasonable cut, and never seems to bog the saw. Most cuts are glueable as-is for edge joining. It's cut to full blade height in some tough stuff...most recently it chomped through several linear feet of 12/4 quartersawn wine vat white oak without a whimper. The real kicker is that it's been being clearanced for ~ $10, so I've got a couple of them. Nicely made with enough carbide to last several sharpenings. Unfortunately it's in limited supply under the Irwin Woodworking series name but should be available as an HO Schumacher & Sohn for ~ $45.

The DeWalt DW7124TK is every bit the equal of the Leitz/Irwin ripper, but without the variable pitch. It has very similar geometry otherwise, and very similar performance. It's also gone through everything I thrown at it with an acceptably clean cut by ripper standards. These UK made blades are getting hard to come by as the DW series 40....as mentioned earlier, I strongly suspect the new DW "Precision Trim" series is replacing the series 40. Both versions go on sale at very reasonable prices.

The German made Leitz/Delta Industrial 10T ripper was purchased mainly as a novelty just to see what it'd do....a clearance price of $15 seemed like a bargain to me. It's a full kerf that's got huge flat top teeth at a steep 20 degree hook and huge gullets. It feeds comparably to my top two 24T TK rippers but the cut suffers in comparison...it's predictably rough. On a 3hp+ industrial saw, this blade would go to town on the thickest densest material you've got. Leitz is no longer making these blades for Delta.

The Italian made Freud LM72R010x was my first high quality ripper. It has a standard full kerf ripper format of 24 FTG teeth at a 20 degree hook with a Permashield coating. Even though it was full kerf and had a lower tooth count, it had a better feedrate and cleaner cut than my Vermont American and Skil 28T blades. Being full kerf it still bogged my saw down when I'd feed it things like 10/4" hard maple, but it's a still a top shelf ripper that's nicely suited for a 3hp+ cabinet saw.

The Leitz Pro 30T ripper with a negative hook was also an impulse buy based primarily on price and curiosity. It's a full kerf that deviates from standard rippers in that it has ATB teeth and a negative hook angle. As a result it cut's a bit cleaner than most rippers but doesn't feed as fast. It's really designed for use on RAS, but it functions reasonably well as an inexpensive glueline ripper (GLR).

The Vermont American 28T ATB ripper was another disappointment to me. Even in a TK configuration with ATB teeth, it neither cut well or aggressively. The icing on the cake was it's rapid dulling. Highly recommended for that pesky neighbor you dislike!

The Skil 28T ATB ripper is identical to the Vermont American version as best I can tell. It was clearanced for $7 so I gave it another shot. This one was sharper than the VA ripper, and performed better for a short while before dulling prematurely. What can I say? ...these aren't very good blades...

[lcm1947]

Hey this is great. It looks like you really put some effort into these tests and they are terribly interesting. I appreciate you doing all this and sharing it. Well, since I'm a one blade kinda guy it looks to me that the Freud LU88 is clearly the winner if you factor in price too. I currently have the 40 tooth TK WWll that I paid $89.00 for and am very happy with it so was going to be buying another one just as soon as I could afford it but I am now thinking about trying the Freud LU 88 blade. Again thanks for sharing. Very interesting and fun to see these results.

[sparkeyjames]

What no low end Freud Avanti blades? I have the 50 tooth thin kerf combo and it has the same gullet pattern and hook angle as the Freud 50 tooth combo. It seems to work well gives fairly clean rip edges and crosscuts are not bad. Does a fair job on laminated sheet goods (plywood) as well. It differs from the (red) Freud 50 tooth combo blade in that there are no laser cut expansion slots and all teeth ether have a left or right cant where as the Freud blade the 5th tooth, as counted from one large gullet to another, is a flat raker. The main body of the blade may or may not be the same type/grade of steel as the Freud but I am not sure of this. I am not using it in a production environment so as a hobby blade where cost is an issue and you dont care about cutting flat bottomed slots or flat bottomed cheap and quick dado cuts with the blade then it might be a decent choice.

Oh yeah and good work on those charts and reviews. Plenty of info to help make a choice for my next blade purchase.

sparkeyjames

[Knottscott]

Hey Sparky - No Diablo or Avanti blades in the lineup. I've been tempted by a few sale prices but the Industrial line on sale is often really close in price (or even lower), and is considered a step up in performance. Amazon seems to put the Industrial line on sale alot so that's where the deals have been.

[Knottscott]

Hey this is great. It looks like you really put some effort into these tests and they are terribly interesting. I appreciate you doing all this and sharing it. Well, since I'm a one blade kinda guy it looks to me that the Freud LU88 is clearly the winner if you factor in price too. I currently have the 40 tooth TK WWll that I paid $89.00 for and am very happy with it so was going to be buying another one just as soon as I could afford it but I am now thinking about trying the Freud LU 88 blade. Again thanks for sharing. Very interesting and fun to see these results.

Hard to go wrong with the LU88 if you're looking for a backup with some different strengths from your WWII....heck, it's a great primary blade! It's really been a nice blade for me.

[jackellis]

Would you say all but the last two or three blades in each category of your lineup do a respectable enough job based on the overall scores? I have not studied the charts in too much detail but it seems if I avoid the last two or three blades in each group, I'll get at least satisfactory results for the listed purpose.

[leehljp]

If you decide to do another update later, I would love to see the kerf thickness listed. If I remember correctly, there are different thicknesses listed as TK, and this has played a big part in my choice of blades in the past. Being in Japan now, I don't get to see the US choices as much but all blades here list the thickness in tenths of MM, and each mfg has several thickness for each blade. I will be retiring in the next 3 to 4 years and will be returning to the States, at which time I will be checking kerf thicknesses when purchasing there. More than likely, I will be settling on the WW11 TK as the standard, but would use another if it gave quality cuts with thinner kerfs.

I know purist who never consider kerfs other than the regular kerf chosen by the manufacturer. You mentioned the thin kerfs as allowing faster feed rate on lower powered saws. This, for me, was never a consideration.
With the cost of lumber since the '70s, with the decrease in availability of good lumber readily available even from saw mills, - thin kerf with quality cut has been my number 1 priority in choosing a blade since then.

Thin kerfs allow me to get a LOT more out of a board than regular kerfs do. The idea that it allows faster cuts on lower powered saws never enters into the equation for me in buying a blade. But kerf thickness or thinness + quality of cut does.

The cost of good lumber and eliminating as much waste as possible should be driving the need for thin kerf, not feed speed rate. I can't tell you the number of times I figured the kerf thickness in with ripping boards for a project in order to determine which board to use - so that I could waste the least wood. I do this even on plywood.

1/8 and even 1/16 inch too narrow of a board or plywood will force the use of another board or sheet of plywood. Thin kerfs and kerf thickness considerations make ALL the difference in the world in allowing more choices in which board or piece of ply to use. Feed RATE plays far less importance in furniture crafting than wood usage.

I don't expect your chart to be updated for me, but if it is available in the future, I will definitely use it. That chart is great! I missed it the first time around and I am putting this link in my "special links" folder.

[cabinetman]

Anybody know where to get some sawblade information?

[Knottscott]

Would you say all but the last two or three blades in each category of your lineup do a respectable enough job based on the overall scores? I have not studied the charts in too much detail but it seems if I avoid the last two or three blades in each group, I'll get at least satisfactory results for the listed purpose.

Hi Jack - Yes, that'd more or less be my conclusion, especially in the first chart where any of the top 14 performed at what I'd consider an acceptable level for general purp use. High quality doesn't necessarily have to be high cost, but be aware that some of the lower grade cutters work pretty well for a while....then fade quickly leaving you needing a replacement or a sharpening. All of those at the top end of my charts should perform well for a reasonable length of time between sharpenings...depending a lot on usage.

[Knottscott]

... I will be retiring in the next 3 to 4 years and will be returning to the States, at which time I will be checking kerf thicknesses when purchasing there. More than likely, I will be settling on the WW11 TK as the standard, but would use another if it gave quality cuts with thinner kerfs.

Hi Hank - I'm actually more concerend with cut quality than with speed in most cases, but I do find that the potential for a faster feedrate gives me more control and flexibility with wood thickness, and is always more desirable to me than being a forced by a slower feedrate. My project rate is small enough, and I'm in the NE where wood is plentiful, so I suppose I'm less concerned with waste at this point. Most of the TK's I used ranged from 0.094" to 0.100".

I understand that Tenryu has some ultra TK's, and I've read about a very thin Matsushita 7=1/4" 40T ultra TK that's supposedly pretty impressive. Do you hear more about those blades than we do?

...speaking of wood waste...testing saw blades tends to waste quite a bit!

[leehljp]

I understand that Tenryu has some ultra TK's, and I've read about a very thin Matsushita 7=1/4" 40T ultra TK that's supposedly pretty impressive. Do you hear more about those blades than we do?

...speaking of wood waste...testing saw blades tends to waste quite a bit!

I have access to the Tenryu blades here, but they all are made for the metric arbors. Believe it or not, Tenryu are not as big a deal here as they are in the States. They are sold and used here, but so are other quality brands. The Tenryu brand is regarded as a very good quality blade, but so are some other brands. Same for TOOL brand respect. Here, Hitachi is regarded as the defacto standard for quality and toughness. I would have thought Makita, from my experience with Japanese tools in the States.

They make lots of TK quality cutting blades here. The arbors here are metric and the metric sizes usually have smaller arbor holes than the comparable US diameter blades, making arbor adapters for US saws a moot point.

On the smaller blades, 6 in, 7 1/2 inch size, I use a 1.3 and 1.5 mm kerf for fine cutting and of course thicker kerfs for general cutting. I bought a 7 1/2 equivalent (190 mm) Makita saw and made a "table saw" out of it to cut pen blanks. I am still working on it and am on the second table. I use the 1.3 mm blade and will use a 1 mm blade if I can find one. When I get this perfected (hopefully finish in August) I will post a picture of it here.

The thin blades help in making fine slits, segments, kerfs and inlays in pens, as well as wasting less wood. This is specially important when there is barely enough wood for two pens if the right kerf is used. Specialty band saw blades aren't much thinner but leave rougher cuts, which are not conducive to segmenting and nice inlays in kerfs.

In pens making, there is one procedure often referred to as celtic knot, where the kerf thickness is critical to making a good "knot". The procedure requires the segment to be the precise thickness of the blade kerf (minus the expected glue thickness) for proper alignment.

In this link, you can see how matching or MISmatching kerf thickness with the segment affects the outcome. Scroll down and see several different ones.