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1/2" Router Bit vs 1/4" Router Bit; Which To Use And When?

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Forum topic by LGLDSR73 posted 07-31-2021 05:16 PM 1309 views 0 times favorited 46 replies Add to Favorites Watch
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LGLDSR73

108 posts in 2983 days


07-31-2021 05:16 PM

Topic tags/keywords: router bit dovetail

Hi All,

I recently ordered a Porter Cable 4216 Dovetail Jig which will be arriving today. I have a question about Bits.

Freud has a 1/2”, 14 degree, 1/4” shank, P/N 22-104. They also have a 1/2”, 14 degree, 1/2” shank, P/N 22-112.

Other than the size of the shank, what is the difference between the two? Is it an application issue? I.e., drawers versus small boxes?

When would you choose a 1/4” Bit over a 1/2” Bit and vice-versa? I plan for now to be making boxes no larger than 6” x 6” with a Bosch 1617EV Router.

As always, many thanks.

Lyman

-- "For God so loved the world that he gave his one and only Son (Jesus), that whoever believes in him shall not perish but have eternal life." - JOHN 3:16


46 replies so far

View Fred Hargis's profile

Fred Hargis

7197 posts in 3709 days


#1 posted 07-31-2021 05:50 PM

I’m not familiar with the PC jig, but most of them require you to use bushings and the 1/2” shank bit make not work in all cases. That said, I’ll always use a larger shank bit versus a smaller one when I have a choice. I’ve bought some with 3/8” shanks (I have 3/8” collets for 2 brands of routers) just to avoid the smaller shanks.

-- Our village hasn't lost it's idiot, he was elected to congress.

View therealSteveN's profile

therealSteveN

8656 posts in 1790 days


#2 posted 07-31-2021 06:18 PM

I also stay away from 1/4” shanks if possible. The only time I will use them is if the application begs for use of a small hand held trim router, which are limited to 1/4” shanks. The 1/2” shanks have been available for industrial use for some time, but for hobbiest use and hand held routers are still not main stream. Evidenced by what you can run out and buy at the Big Box stores. As they become more the “norm” I expect even trimmers will allow for 1/2” shanks, or at least 8mm (appx 5/16) or 3/8”

Leigh is fond of the 8mm, otherwise in the US they aren’t real heavily used.

I have a PC 4212, and it came with bits. Not sure, but I’d get the jig, and see what they gave you.

-- Think safe, be safe

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LGLDSR73

108 posts in 2983 days


#3 posted 07-31-2021 07:13 PM

Many thanks to both of you for your input! The Porter-Cable 4216 arrived today and came with both 1/4 and 1/2”.

Again, thank you very much!

Best,

Lyman

-- "For God so loved the world that he gave his one and only Son (Jesus), that whoever believes in him shall not perish but have eternal life." - JOHN 3:16

View SMP's profile

SMP

4728 posts in 1121 days


#4 posted 07-31-2021 07:35 PM

Some people have snapped 1/4 bits. and a lot of larger cabinet door, panel bits , etc only come in 1/2”. i’ve never had that problem but i tend to buy decent quality and don’t go ape on my tools. that said, i tend to buy 1/2” shank bits when possible that way i don’t have to change the collet out(or find the other one) . as i tend to keep my router in the table for moulding, cabinet doors.

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splintergroup

5743 posts in 2438 days


#5 posted 07-31-2021 07:52 PM

Some DTs with narrow pins don’t have the clearance for the 1/2” shank to pass through when cutting, otherwise unless you need a small diameter cutter or on a budget, 1/2” is the way to go.

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LGLDSR73

108 posts in 2983 days


#6 posted 07-31-2021 08:07 PM



Some DTs with narrow pins don t have the clearance for the 1/2” shank to pass through when cutting, otherwise unless you need a small diameter cutter or on a budget, 1/2” is the way to go.

- splintergroup


Agreed. From 2004 through 2008 I had an extensive array of bits and virtually all of them were 1/2”. Then Life got in the way and everything had to be sold so given the time span between 2008 and now I really am playing catch up on a lot of this.

Thank you for taking the time to respond, I do appreciate it very much.

Best,

Lyman

-- "For God so loved the world that he gave his one and only Son (Jesus), that whoever believes in him shall not perish but have eternal life." - JOHN 3:16

View WoodenDreams's profile

WoodenDreams

1412 posts in 1127 days


#7 posted 07-31-2021 08:17 PM

+1 with the above. I have both 1/4” and 1/2” shaft bits. Never have a problem with 1/4” shafts yet. If the cutting portion of the bit is the same size, the cut is the same. The difference really is in the shafts’ strength. Routing the denser woods (such as hickory) the shaft could possibly bend with the 1/4” vs. 1/2” if taking too big of a cut, or when heating up the bit. The advantage to the 1/4” bit, is that it will also fit the ‘trim routers’.

View Rich's profile

Rich

7369 posts in 1805 days


#8 posted 07-31-2021 10:27 PM


Many thanks to both of you for your input! The Porter-Cable 4216 arrived today and came with both 1/4 and 1/2”.

- LGLDSR73

It’s not an either/or proposition. The reason you got bits with both 1/4” and 1/2” shanks is because the 4216 has templates for regular dovetails, and small dovetails. The 1/2” bits are sized for the large template, and the 1/4” for the small one. They are not interchangeable.

If you wish, both Whiteside and Freud make bits with 1/4” shanks that are compatible with the larger template. You will have to purchase them separately. Just match the specs of the ones you have—7º 17/32 inch dovetail and 13/32” for the straight bit.

Also, ignore the nonsense above regarding 1/4” shanks. For this application they will work just fine.

-- Half of what we read or hear about finishing is right. We just don’t know which half! — Bob Flexner

View Jimarco's profile

Jimarco

66 posts in 2323 days


#9 posted 07-31-2021 10:30 PM

Personal preference is 1/2” for strength/safety concerns. As you said Lyman the bits come with the jig. I have replaced the bits with PC bits and an off brand and all worked fine.

You may want to consider adding 2 items for your PC 42 jig, a second router to save time and aggravation changing bits and set up also consider Leigh’s VRS1200 Vacuum & Router Support for 4200 Series Porter-Cable Dovetail Jigs. It saves you from a chest and floor full of shavings plus gives the router support. Without the added support it’s easy to nick the template with the bit by having to remove the router after the cut… don’t ask

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LGLDSR73

108 posts in 2983 days


#10 posted 07-31-2021 10:32 PM

SMP, Splintergroup, WoodenDreams,

Hadn’t really considered the possibility of the 1/4” Bits snapping but I see your valid points – all good. Thanks for the heads up on that.

Always learn something here. Thanks guys.

Best,

Lyman

-- "For God so loved the world that he gave his one and only Son (Jesus), that whoever believes in him shall not perish but have eternal life." - JOHN 3:16

View Madmark2's profile

Madmark2

3063 posts in 1804 days


#11 posted 07-31-2021 10:49 PM

1/2” is 4x stronger than 1/4”. I push lots of hard hardwoods (jatoba, ipe, wenge, etc.) so carbide is the order of the day. Heat is the enemy of cutters. In addition to being 4x stronger, 1/2” bits also dissipate 4x the heat, not to mention the general heat mass increase of the bigger cutter and mount.

I use 1/4” bits with a 1/8” rounder in my trim router. The intermediate router is the PC plunger for template routing. Even the 1/4” shank bits are all carbide.

I don’t resharpen, I replace. Most of my patterns get occasional use, some get used to death. I buy as needed, no “collections”, but I do buy matched panel/rail/stile sets. I’ve prolly’ got well over a grand in bits plus that twice again in the wing, mount, inlay and pattern accessories.

The router, not the saw, is the most expensive tool in the shop. The saw gets its annual $75 blade. The router gets new patterns all the time. Even a lousy 1/4” shank solid carbide 1/8” inlay bit is $20. I have to inventory spares so a snapped bit doesn’t stop a project.

-- The hump with the stump and the pump!

View LGLDSR73's profile

LGLDSR73

108 posts in 2983 days


#12 posted 08-01-2021 12:37 AM

Many thanks to both of you for your input! The Porter-Cable 4216 arrived today and came with both 1/4 and 1/2”.

- LGLDSR73

It s not an either/or proposition. The reason you got bits with both 1/4” and 1/2” shanks is because the 4216 has templates for regular dovetails, and small dovetails. The 1/2” bits are sized for the large template, and the 1/4” for the small one. They are not interchangeable.

If you wish, both Whiteside and Freud make bits with 1/4” shanks that are compatible with the larger template. You will have to purchase them separately. Just match the specs of the ones you have—7º 17/32 inch dovetail and 13/32” for the straight bit.

Also, ignore the nonsense above regarding 1/4” shanks. For this application they will work just fine.

- Rich


Thanks Rich.” Just match the specs of the ones you have—7º 17/32 inch dovetail and 13/32” for the straight bit.” As I mentioned above the 4216 came with a 1/2”, 1/2” shank, 7 Degree and I just ordered a Freud 1/2” (Dia.) Dovetail Bit with 1/2” Shank (22-112) 14 Degree. This will work in the half-blind template, correct?

The bit I ordered is here

Many thanks,

Lyman

-- "For God so loved the world that he gave his one and only Son (Jesus), that whoever believes in him shall not perish but have eternal life." - JOHN 3:16

View LGLDSR73's profile

LGLDSR73

108 posts in 2983 days


#13 posted 08-01-2021 12:40 AM



1/2” is 4x stronger than 1/4”. I push lots of hard hardwoods (jatoba, ipe, wenge, etc.) so carbide is the order of the day. Heat is the enemy of cutters. In addition to being 4x stronger, 1/2” bits also dissipate 4x the heat, not to mention the general heat mass increase of the bigger cutter and mount.

I use 1/4” bits with a 1/8” rounder in my trim router. The intermediate router is the PC plunger for template routing. Even the 1/4” shank bits are all carbide.

I don t resharpen, I replace. Most of my patterns get occasional use, some get used to death. I buy as needed, no “collections”, but I do buy matched panel/rail/stile sets. I ve prolly got well over a grand in bits plus that twice again in the wing, mount, inlay and pattern accessories.

The router, not the saw, is the most expensive tool in the shop. The saw gets its annual $75 blade. The router gets new patterns all the time. Even a lousy 1/4” shank solid carbide 1/8” inlay bit is $20. I have to inventory spares so a snapped bit doesn t stop a project.

- Madmark2


Thanks for the valuable input! I did not know that 1/2” bits also dissipate 4x the heat as well as being 4X stronger. Much appreciated!

Best,

Lyman

-- "For God so loved the world that he gave his one and only Son (Jesus), that whoever believes in him shall not perish but have eternal life." - JOHN 3:16

View bigblockyeti's profile

bigblockyeti

7566 posts in 2936 days


#14 posted 08-01-2021 01:14 AM

A cutter with geometry the same in a 1/2” shaft bit as a 1/4” shaft bit will not dissipate 4 times the heat. Heat dissipation is a function of surface area and you simply don’t have 4× the surface area just because the shaft is double the diameter. You will have greater ability to absorb heat due to a greater thermal mass and the increased surface area of the shaft will dissipate more heat but the cutter, where the heat is being generated, will not.

The three main reasons for a 1/4” shaft bit are 1) cheaper 2) fits in smaller bushings 3) fits in trim routers.
The benefit of a 1/2” shaft is greater strength and a teeny tiny bit more heat dissipation.

-- "Lack of effort will result in failure with amazing predictability" - Me

View Rich's profile

Rich

7369 posts in 1805 days


#15 posted 08-01-2021 01:17 AM

I just ordered a Freud 1/2” (Dia.) Dovetail Bit with 1/2” Shank (22-112) 14 Degree. This will work in the half-blind template, correct?

- LGLDSR73

No, I’m afraid that won’t work with the PC jig. Your only choice is the 7º 17/32” bit for the large template.

Many other jigs, like the Leigh, use the 1/2” XXº bits, and 14º is.a common one. With the Leigh jig, you use different bits for half blinds, depending on the board thickness. Because they vary in length, but all have a 1/2” diameter cut at the tip, the angle varies, hence the XXº above.

-- Half of what we read or hear about finishing is right. We just don’t know which half! — Bob Flexner

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