Centering Bit

[onewaywood]

Could someone tell me what number centering bit I should buy for pre-drillng.

 

[Glass Scratcher]

Could someone tell me what number centering bit I should buy for pre-drillng.

Check with JohnnyCNC, he sells them.

http://penturnersproducts.com/index.php?main_page=product_info&cPath=6&products_id=47

 

[JBCustomPens]

Could someone tell me what number centering bit I should buy for pre-drillng.

There is no number to use. All center drills drill a 60 degree hole and pre-drill just fine. I use a number 4 I got from JohnnyCNC. Again, he is a great guy to work with and I will always recommend him and his products.

 

[holmqer]

There is no number to use. All center drills drill a 60 degree hole and pre-drill just fine. I use a number 4 I got from JohnnyCNC. Again, he is a great guy to work with and I will always recommend him and his products.

Actually some center drills are 82 degrees and some are 90, for our use generally 60 degrees is good.

I tend to use a number 3 or 4. I use 3 on the smaller kits like 7mm and 4 on larger.

 

[rherrell]

They're so cheap I recommend you get the assortment pack, it's either 4 or 5 drills for just a few bucks. The tip of the drill bit should be equal to or smaller than the center bit.

 

[holmqer]

They're so cheap I recommend you get the assortment pack, it's either 4 or 5 drills for just a few bucks. The tip of the drill bit should be equal to or smaller than the center bit.

I quite agree, I have some by my metal lathe, milling machine, drill press and wood lathe

 

[onewaywood]

Thats great, thank you everyone for the info.

 

[wm460]

A set of 5 centre drills $5 from CDCO.