box joints

underwater · Post by **underwater** » Fri Oct 07, 2011 8:21 pm

Is there a saw blade made to cut the teeth on box ends to join corners.

charlese · Post by **charlese** » Fri Oct 07, 2011 9:30 pm

underwater wrote:Is there a saw blade made to cut the teeth on box ends to join corners.

I assume you want to make box joints. Any dado blade that is adjustable down to 1/4" will work. If you google dado blades you will probably even find a special blade that is designed to make box joints. Better yet, googlebox joint dado blades.

pennview · Post by **pennview** » Fri Oct 07, 2011 10:23 pm

There are saw blade sets designed specifically for making box joints in 1/4" or 3/8" widths. They use two saw blades that fit together to cut the two sizes depending on which faces of the two blades you put together. Here are some examples -- http://www.amazon.com/s/?ie=UTF8&keywor ... do188vv7_b

dusty · Post by **dusty** » Sat Oct 08, 2011 7:04 am

Any dado blade that produces a flat bottomed dado will work but I prefer making box joints on the router table. On a router table it is imperative that you use a backer board to avoid tearout.

wurlitzerwilly · Post by **wurlitzerwilly** » Sat Oct 08, 2011 7:06 am

pennview wrote:There are saw blade sets designed specifically for making box joints in 1/4" or 3/8" widths. They use two saw blades that fit together to cut the two sizes depending on which faces of the two blades you put together. Here are some examples -- http://www.amazon.com/s/?ie=UTF8&keywords=box+joint+blade&tag=googhydr-20&index=tools&hvadid=6099055581&ref=pd_sl_6ddo188vv7_b

What's the difference in operation between those and Shopsmith's Dado Cutter set?
They look like what Norm Abram calls a "Stacked Dado Head Cutter".

pennview · Post by **pennview** » Sat Oct 08, 2011 8:28 am

The box joint set consists of only two blades and will only cut 1/4" or 3/8" slots depending on how you orient the two blades.

Stacked dado sets have two outer blades and five "chipper" blades, one of which is 1/16" thick and the others 1/8" thick. You place the chippers between the two outer blades in various combinations to cut dados between 1/4" and 13/16". Some dado sets come with shims to allow for fine tuning the width of the dados cut.

The box joint sets give you a perfectly square slot, similar to the slot made by a router bit.

The stacked dado set give you square sides and bottom, but the outer blades cut tiny wedges deeper than the bottom where the sides and bottom meet.

Here's a drawing of what a dado looks like using the stacked dado set.

[ATTACH]14443[/ATTACH]

dusty · Post by **dusty** » Sat Oct 08, 2011 8:37 am

Very good explanation. If square bottomed dadoes for important to a project, this is certainly a good solution.

This, used with an Incra fence (or anyone equally accurate), should give you "perfect" dadoes of any size.

I use the router table because it is always set up (convenient). I did not intend to imply (as I might have done) that routers are better than stacked dadoes.

charlese · Post by **charlese** » Sat Oct 08, 2011 7:44 pm

dusty wrote:Any dado blade that produces a flat bottomed dado will work but I prefer making box joints on the router table. On a router table it is imperative that you use a backer board to avoid tearout.

Actually, a backer board is necessary on any box joint cutting. Depending on your box joint jig, even 1/4" hardboard can be used.