# Bench Dog Hole Bit: 3/4" plunge (long)???



## BigJimAK (Mar 13, 2009)

I've been keeping my eyes out for a 3/4" plunge bit for starting bench dog holes. Ideally it'd be 1/2"SH and 4" long or so.

I've seen plenty of 3/4" bits but none labeled as plunge. I know I could use a forestner but a plunge router seems like the ideal way to drill a perfectly perpendicualr hole (yes, that's what I need).

It seems like my On-Point laser base, router and 3/4" plunge bit would be a perfect apporach for dog holes! <ruff>


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## jschaben (Jun 21, 2009)

BigJimAK said:


> I've been keeping my eyes out for a 3/4" plunge bit for starting bench dog holes. Ideally it'd be 1/2"SH and 4" long or so.
> 
> I've seen plenty of 3/4" bits but none labeled as plunge. I know I could use a forestner but a plunge router seems like the ideal way to drill a perfectly perpendicualr hole (yes, that's what I need).
> 
> It seems like my On-Point laser base, router and 3/4" plunge bit would be a perfect apporach for dog holes! <ruff>


MLCS Plunge Cutting Straight Router Bits

I dunno where to get one 4" long though. I'm guessing your bench is 2-3"?

This may work better than my first link though
http://www.mlcswoodworking.com/shop...arthtml/pages/bt_solid.html#spiral_hss_anchor


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## bobj3 (Jan 17, 2006)

Hi Jim

The router is a great tool but not always the right tool,you can make a jig to hold your drill motor and drill a strait hole and use the bit below..or if want a real clean hole use the 5/8" auger bit and than use your new longer router bits and template to clean the holes out to a true 3/4" hole with your router for the dogs..

By the way if you grind off some of the lead thread on the drill bit it will cut a nice clean hole..the threads are in place to pull the drill bit in quick..

3/4 x 4-1/2 In. Solid Center Auger Bits

Irwin 49912 3/4 x 4-1/2 In. Solid Center Auger Bits

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BigJimAK said:


> I've been keeping my eyes out for a 3/4" plunge bit for starting bench dog holes. Ideally it'd be 1/2"SH and 4" long or so.
> 
> I've seen plenty of 3/4" bits but none labeled as plunge. I know I could use a forestner but a plunge router seems like the ideal way to drill a perfectly perpendicualr hole (yes, that's what I need).
> 
> It seems like my On-Point laser base, router and 3/4" plunge bit would be a perfect apporach for dog holes! <ruff>


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## BigJimAK (Mar 13, 2009)

jschaben said:


> MLCS Plunge Cutting Straight Router Bits
> 
> I dunno where to get one 4" long though. I'm guessing your bench is 2-3"?
> 
> ...


Thank you, John...

I'm just getting ready to glue up a working-prototype workbench top and, to be honest, I'm still vascillating on how thick to make it... but yes, it'll be thick. 

That's quite a choice there, John... I really like the spiral bit... it'd be good for my softwood prototype but I wonder if the HSS would hold up to ~35 plunges to full depth in hard maple??? Hmmmm.... I guess it probably should as long as you give time for cooling between cuts.


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## Ralph Barker (Dec 15, 2008)

Just another option:
Buy General Tools AccuDrill Precision Drill Guide, Model 36/37 at Woodcraft.com


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## BigJimAK (Mar 13, 2009)

bobj3 said:


> Hi Jim
> 
> The router is a great tool but not always the right tool,you can make a jig to hold your drill motor and drill a strait hole and use the bit below..or if want a real clean hole use the 5/8" auger bit and than use your new longer router bits and template to clean the holes out to a true 3/4" hole with your router for the dogs..
> 
> ...


Hi Bob,

Using an auger bit was already my back-up plan but I hadn't considered making it undersized and then cleaning it out with my new "George bits"... great idea!! Those bits, after getting lost by the USPS, are supposedly now in Anchrage and being delivered today. I was going to use the long ones to trim the bench-end perpendicular to the top of the bench anyway.

Although it wouldn't be an issue for my softwood top, would an auger bit hold up to drilling 8 - 10' total in hard maple? I've seen several advertisements cautioning about short bit life in wet or hardwood. Is there something special I should be looking for or is it just a matter of pausing regularly to keep the bit cool? I could always pause regularly and shoot a blast of air into the hole to clear the chips (and cool the bit).

Jim


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## Mike Wingate (Apr 26, 2009)

I use 3/4" square bench dogs on my benches. I route the grooves across the edges, and then put extra lengths alongside to the widen the bench on both sides. Thus I have square holes running 3" inside the edges of the bench. I have done this on a number of benches, both solid and manmade centres to the bench with solid dog areas. If you want round dogs, turn the tops round. My Rockler Bench Cookies fit in the dog holes on their extensions.


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## bobj3 (Jan 17, 2006)

Hi Jim

They are HSS and you can put a new edge on them very easy but just put some candle wax/paraffin (canning wax) on them and they will stay cool..  don't use water on them or any water base lube they will rust up in time.. I have many from 1/4" to 3" in diam. and from 4" to 20" long they do come in handy 

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BigJimAK said:


> Hi Bob,
> 
> Using an auger bit was already my back-up plan but I hadn't considered making it undersized and then cleaning it out with my new "George bits"... great idea!! Those bits, after getting lost by the USPS, are supposedly now in Anchrage and being delivered today. I was going to use the long ones to trim the bench-end perpendicular to the top of the bench anyway.
> 
> ...


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## Cherryville Chuck (Sep 28, 2010)

I drilled a hole with a drill press through a 4x4 and used it to start the holes straight.


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## Racer2007 (Nov 3, 2010)

Ralph, I bought one of thoes General guidess and am going to throw it in the trash. There is almost 1/4" of play in the chuck so that when I put a bit in it and try to drill I get a side to side motion along with the spinning motion . I thought it might have just been a bad one but took it back to the store and checked 3 more in the boxes and they all the same issue.


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## Phil P (Jul 25, 2010)

Cherryville Chuck said:


> I drilled a hole with a drill press through a 4x4 and used it to start the holes straight.


I'm with Chuck on this one. If you can't drill a hole dead vertical by eye then a home-made jig like Chuck suggests is just the ticket


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