[ejant]

I only have up cut spiral bits.

The down cut spiral bits are more for finish work.

Is there a noticable difference between the two and does it pay to have both.

 

[BobandRick]

Downcut spiral bits push the cuttings into the cavity or away from the table on a tablemounted external/internal routing. I don't own any. Maybe someone else can shed some light on the value of owning them.

 

[reible]

Down spiral has the "edge" on the top surface (router side) coming out nicer, less splinters (think thin veneer). I've used it only as a through cutter, when hand held it makes it easier to see what is happen as the chips are taken away from the router.

They also make a compression up and down spiral bit that cuts down from router and up from the bottom side...... I don't have one of these.........

Ed

 

[ejant]

I've been doing some reading on the spiral bits. The downcut bits are excellent for inlay work give a nice clean edge.

 

[viper1]

Also great for plywoods or any wood that splinters easy on the surface.