Cone bit and unibit

Status
Not open for further replies.
P

powerplay

Senior Member
Location
In front of a computer.
JJWalecka said:
Does anyone own a cone bit? Is there an advantage to the regular step bits?
Click to expand...

It looks to me like an step bit would leave an even hole in the #12 gauge metal it drills through... this cone bit looks like it would leave an sharp angled cut which may cut someone installing the connector. I've never seen one with no ridges...where did you get it, or was it grinded down?
 
F

fmtjfw

Senior Member
Location
Fairmont, WV, USA
A Step bit allows you to make a hole with a definite diameter easier. The cone bit would make that difficult to do free hand. It might work ok in a drill press with a fixed stop. The cone bit would also make a hole with different diameters inside and outside in any material with some thickness to it.
 
GUNNING

GUNNING

Senior Member
Location
Gainesville, Florida
Hoarding

Hoarding

I bought 2 unibits 20 years ago. Burned em up within several days . Being a pack rat I still have one of them on the van because I can not bring myself to throw a $50 ruined bit away.:slaphead:
 
J

jusme123

Senior Member
Location
NY
Occupation
JW
powerplay said:
It looks to me like an step bit would leave an even hole in the #12 gauge metal it drills through... this cone bit looks like it would leave an sharp angled cut which may cut someone installing the connector. I've never seen one with no ridges...where did you get it, or was it grinded down?
Click to expand...

...not impossible, but almost impossible to be cut installing a connector on sharp edger metal from hole, any hole saw leaves a sharp edge.
 
JJWalecka

JJWalecka

Senior Member
Location
New England
GUNNING said:
I bought 2 unibits 20 years ago. Burned em up within several days . Being a pack rat I still have one of them on the van because I can not bring myself to throw a $50 ruined bit away.:slaphead:
Click to expand...

I find that there is always one spot on the larger unibit that gets dull. Wondered if the cone bit would eliminate that. Guess ill have to get one and find out.
 
kwired

kwired

Electron manager
Location
NE Nebraska
GUNNING said:
I bought 2 unibits 20 years ago. Burned em up within several days . Being a pack rat I still have one of them on the van because I can not bring myself to throw a $50 ruined bit away.:slaphead:
Click to expand...

I hate to accuse you of wrongdoing, but how? As with any drill bit in metal, excess speed makes more heat and damages the bit as well as hardens the material being drilled - making it even harder to drill. Other than running too fast these bits generally are not that easy to damage that quickly.

I find them to be great for enlarging an existing hole, but never did like them for drilling a new hole.
 
renosteinke

renosteinke

Senior Member
Location
NE Arkansas
I have never seen the 'cone bit.' I wonder if it drills at all, ot just reams the perimeter.

Drill bits have their tips ground at specific angles. For metal, this angle is around 132 degrees, and the 'steps' of the Unibit are at that angle.

I would have low expectations for the 'cone' bit ... unless I was using it to remove pipe-cutter burrs from conduit.
 
GeorgeB

GeorgeB

ElectroHydraulics engineer (retired)
Location
Greenville SC
Occupation
Retired
JJWalecka said:
Does anyone own a cone bit? Is there an advantage to the regular step bits?
Click to expand...
I've used the single flute countersinks for years, most of which are the same concept. As a bit, the tapered hole would seem to be a disadvantage ... but what do I know?
 
renosteinke

renosteinke

Senior Member
Location
NE Arkansas
You 'sharpen' a Unibit by grinding away at the long 'trough' that creates the cutting edge. You don't touch the tapered faces of the bit at all.

Naturally, you cannot replace the TiN coating.
 
Status
Not open for further replies.
Top