180 Degree drill bits

[zorrox]

I picked up these drill bits for pretty cheap at a garage sale, but I have never seen bits that are completely flat tipped like this. What are these used for? It seems like the bit would slide around a lot before starting to drill.

 

[ocloc24]

Same concept as a blind tap. For instance so you can drill into an object and the bottom of the hole can be flat. Then you can thread the entire depth of the hole with a blind tap. Ideally you wouldn't be starting a hole you're drilling with this type of bit. You would use a normal drill bit and a depth guide and drill just up to where to want the bottom of the hole to be, then finish with this bit.

 

[Sticky Grips]

Never seen a bit like that before. They probably drill similarly to an end mill when you do a plunge cut....or someone just went crazy with a grinder.

 

[rlitman]

I can't say I've seen that either. It looks awfully like an end mill, but longer like a drill bit.

Once a hole is established, I could see this boring better than a regular bit. The straight across tip has shorter cutting edges than an angled tip, so it will require less torque to cut.

 

[DavidB]

ocloc has it correct. They're for flattening the bottom of a hole you drilled with a regular (pointed) drill bit.

 

[Roberts210]

Ditto Ocloc.

 

[zorrox]

Cool, thanks guys!

 

[Mohawk Dave]

If you want to sell them I may be interested in buying