# countersinks in oak



## rstermer (Apr 22, 2008)

I'm building a bracket out of oak for a folding workbench I'm making. I tried to countersink a hole in the bracket so a screw would go in flush but the countersink chattered on me and left a really ugly looking countersink. What adjustments do I need to make to get it to come out smooth. Also, in general, when going from softwoods to hardwoods, what changes should one make in tool speed, etc. pretty much everything I've worked on heretofore has been made out of pine.
Thanks for your assistance.

rstermer


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## bobj3 (Jan 17, 2006)

HI rstermer

Speed is the key the norm,,,do you have a small palm router ? if so chuck up the counter sink and use the router like a drill motor..with a light touch.

They make counter sinks types 1 cutter ,2 cutters,3 cutters ,6 cutters, the one that works best in wood/plastic is the 6 cutter type,it takes less of a bite but put in a very fine counter sink hole ,but the router will do a fine job with the standard counter sink because of the speed of the tool spinning at high speed..

Once you have it chuck up use some scrap stock to get the fell of it..


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rstermer said:


> I'm building a bracket out of oak for a folding workbench I'm making. I tried to countersink a hole in the bracket so a screw would go in flush but the countersink chattered on me and left a really ugly looking countersink. What adjustments do I need to make to get it to come out smooth. Also, in general, when going from softwoods to hardwoods, what changes should one make in tool speed, etc. pretty much everything I've worked on heretofore has been made out of pine.
> Thanks for your assistance.
> 
> rstermer


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## rstermer (Apr 22, 2008)

Hi Bob- Thanks for your reply. I found a set of 6 flute countersinks on the Grizzly site for not much money. 

Just want to make sure I understand the adjustments to make for hardwood. When working hardwoods tool speed should go up, not down? Router on highest speed, drill press at the top of the range for the drill size being used, etc?

Also, will feedrates change a lot?

Thanks for the clarification.
rstermer 




bobj3 said:


> HI rstermer
> 
> Speed is the key the norm,,,do you have a small palm router ? if so chuck up the counter sink and use the router like a drill motor..with a light touch.
> 
> ...


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## HDS (Jun 3, 2009)

Hi RStermer,
BobJ is spot on, as a general rule, the harder the material the higher the cutting speed.
That's why your dentists drill sounds like a wailing banshee.
This is why woodsaws have only 6 teeth per inch whilst hacksaw blades for cutting steel have tiny 25-40 tpi.
Router speeds for soft pine should be set to minimum to reduce burn and keep the tool cool, however for a fine finish on hardwoods like Oak, Mahog, etc should be at the upper reaches of your routers speed.
Another deciding factor for tool speed is the physical size of the bit.
Small tools require higher operating speeds and lighter cuts to reduce bit loads.
Larger tools need lower speeds and light cuts will reduce tool stress.

Best regards,
Henry.


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