Router Bit: Straight vs Spiral

[TealaG]

I have recently discovered the joy of a spiral router bit (it seems to cut smoother/easier than a straight bit).  Other than flush trimming, are there times when you'd prefer a straight bit over a spiral?  Or would you always use a spiral instead of a straight?

 

[epicxt]

I pretty much always prefer spiral. I do a lot of template/mortise/inlay work.

 

[aloysius]

Even flush cutters benefit from a slight helical offset in the direction of their bearing surface.  As with most edge tools, a "slicing" cut often provides more splinter & chatter free performance.

Nevertheless, straight cutters are often a much more economical alternative, made from TCT cutting edges brazed to a steel former.  The more radically helical edged cutters tend to be milled (expensively) from solid carbide.  Their curved edges simply can't be resharpened easily, let alone user honed.  Straight cutters are quickly, simply & easily honed by the user with a credit card sized diamond hone, prolonging their life all but indefinitely.

 

[Svar]

I use spiral whenever possible. Straight bits though come in greater variety of sizes.

 

[ear3]

Right -- you can't get spiral bits in >1/2 sizes (except for those monstrous compression bits that Whiteside has popularized).  And it gets expensive if you want to spiral at odd sizes under 1/2".

I use spiral whenever possible. Straight bits though come in greater variety of sizes.

 

[Cheese]

Right -- you can't get spiral bits in >1/2 sizes (except for those monstrous compression bits that Whiteside has popularized).  And it gets expensive if you want to spiral at odd sizes under 1/2".

For the path less traveled, try Onsrud.

Here's their selection of metric bits for wood, plastics & composites. Upcut & downcut in HSS and carbide.http://www.onsrud.com/files/pdf/2014LMTOnsrudMetricProductionCuttingTools.pdf

Here's their selection of imperial bits for wood, plastics, composites & foam.http://onsrud.us.com/assets/2017LMTOnsrudProductionCuttingToolsCatalog.pdf

I've also used SGS, OSG and other brands of carbide end mills made for machining aluminum and they work well on wood products. They're usually cheaper than the cutters marketed for woodworking.    [tongue]

 

[TealaG]

Thanks for the advice!  I had damaged a cheesy straight bit and had so much more success with the spiral bits!!!  I think I'll use the spiral bits first and only use the straight when I "need" to.  Of course, I bought nice Freud bits (spiral and straight) so it might be ok either way since they are better quality than the crap I had.