Replies

1. 
   elmaduro | Nov 21, 2021 11:44pm | #1

   I'd go with the downcut bit. The chips will be pulled down and away from the work. If you happen to cut mortises by lowering the stile down on the bit, the benefit of the downcut becomes obvious.

1. 
   esch5995 | Nov 21, 2021 11:54pm | #2

   I think I need to correct you on this in a router table unless you are cutting through the stock you want to use an upcut bit to pull the chips out of the cut. Keep in mind this will actually result in the chips being moved downward. If you were to use a downspiral bit the chips would be pushed into the cut and build up, creating more heat, burning, and shorten bit life. If you are through cutting in a single pass in really doesn't matter much.

1. 
   elmaduro | Nov 22, 2021 01:04am | #3

   You are correct. Using an upcut bit in a router table will pull the chips down towards the shank. I had them flipped. Thanks.

2. 
   rob_ss | Nov 22, 2021 02:42am | #4

   As with all things woodworking, it depends.

   An upcut bit will clear chips most effectively from non-through cuts, and will reduce chipout on the uppermost surface of the work for through-cuts.
   A downcut bit will minimise chipout on the lowermost surface.

   For most case uses, a spiral upcut bit is preferred.

   A word to the wise though - I bought a 2 inch bit thinking that as I needed it for some deep mortises, it would be able to do shorter work too. This is in fact true, but it is not good at doing either - save for very light, or constrained plunge cuts, it is prone to vibration. Sure, with practice this is less of an issue, but there is not 'one bit to rule them all' as I had hoped. Unless you need do cut really deeply, buy a shorter bit!

3. 
   user-6851987 | Nov 22, 2021 07:22am | #5

   I appreciate all of you sharing your knowledge! It was just a bit (no pun intended,LOL) confusing to me as which to purchase! Thank You for sharing.

1. 
   esch5995 | Nov 22, 2021 07:46am | #6

   For the future the only time to use a downspiral bit is if you are through cutting in a single plunge usually with a hand held router although it is okay to do so in a router table if you are plunging through, but keep in mind that you will be fighting gravity. This is why upspiral bits are much more prevalent.

4. 
   user-6851987 | Nov 22, 2021 08:23am | #7

   I’m generally going to use the bit in a router table, routing dado’s. So you’re saying Upcut? But sometimes just using in a handheld router, so my best option?

1. 
   esch5995 | Nov 22, 2021 05:27pm | #10

   Regardless of whether you use it in a router table or handheld router buy an upspiral or up cut bit it is by far the more versatile bit. Down spirals have limited applications where they may have a slight advantage and you will probably never need one.

5. 
   jharveyb | Nov 22, 2021 09:56am | #8

   You want an up-cut bit for dados. The down-cut bit will drive the chips into the groove, and your dado will likely get shallower as you proceed. Plus you will be fighting to keep the board down on the router table against the push of the bit.
   The only situation that I know where a down spiral bit is far superior is when trimming plastic laminate or veneer with a flush trim bit. Here the down spiral bit prevents any chipping out upward of that delicate surface that will show.
   My first spiral router bits were steel, and didn't last. Now I buy the solid carbide ones. I use them for plunge routing, but generally use straight carbide tipped bits for dadoing and rabbeting.
   When I bought my first router in 1975, the guy handed it to me and said, "You just bought half a tool." Considering how much I've spent on routers (and I have at least 5) compared to router bits, he should have said "one fourth". I only buy them as needed.

6. 
   user-6851987 | Nov 22, 2021 11:37am | #9

   Awesome information, Thank You for taking your time to help and educaite. I appreciate it.

7. 
   [email protected] | Jan 02, 2022 01:38pm | #11

   I just used a solid carbide up cut router bit to create 56 mortices for floating tenons.I have a router driven mortising machine cobbled together from the mortising attachment from European multi function machines.That carbide bit did not dull or slow down one bit.The material was hard maple