name that tool

[piman]

Hello Scott,

"Some do try to use them in pillar drills......... but really a bit of an pointless excercise."

Sorry but I have to disagree, they do give a more accurate start to a hole than going in straight with a twist drill. Also useful to start a drilling through a round bar.

Alec

 

[pidgeon chit welder]

Number 2 is an SDS (or maybe SDS+?) drill. Basically a proper hammer drill bit, that fits into a drill without a chuck

We need to see the end of this drill for I suspect that it may be an SDS star drill as used for cavity wall insulation work or rock drilling

 

[Hitch]

Did no1 have a hole through the centre...?

 

[pidgeon chit welder]

Hello Scott,

"Some do try to use them in pillar drills......... but really a bit of an pointless excercise."

Sorry but I have to disagree, they do give a more accurate start to a hole than going in straight with a twist drill. Also useful to start a drilling through a round bar.

Alec

Car thieves like them in battery drills as well for the door locks falls to bits PDQ had my BT van done & cleaned of all tools three times, all with centering bits in the locks back in 1994.

 

[brightspark]

the threaded milling cutters fit in an autolock chuck . they will fit in a drill chuck but will probably slip :due to the shank being hard

 

[breezer]

Did no1 have a hole through the centre...?

Ooops sorry forgot - will check

 

[hareng]

Them Clarkson cutters wont slip any more in a decent drill chuck than them crap ER collets and such like plus take an eternity to change over.

Centre drill or not depends upon whether decent drills and machine speed lus any flex. Usefull on round or tube as in a lathe. Looks like a BS4 by the way.

 

[pete23]

Hello Scott,

"Some do try to use them in pillar drills......... but really a bit of an pointless excercise."

Sorry but I have to disagree, they do give a more accurate start to a hole than going in straight with a twist drill. Also useful to start a drilling through a round bar.

Alec

must say, ive got to agree with you there, why are they called a centre drill??

 

[Pete.]

must say, ive got to agree with you there, why are they called a centre drill??

They are called a center drill because they were designed for drilling holes in the end of stock for turning between centers in a lathe. Te angled taper it creates locates on the lathe center, and the pip on the end is for making a tiny pocket to hold lubricating oil for the center.
They aren't intended as an acurate stating drill for a normal hole (even if they do a good enough job of it). For that, you would use a spotting drill or stub drill. Those have long shanks and short flutes so they stay rigid and a split-point grind so they don't wander.

 

[breezer]

Did no1 have a hole through the centre...?

Yes

 

[langy]

They also break easily

They are called a center drill because they were designed for drilling holes in the end of stock for turning between centers in a lathe. Te angled taper it creates locates on the lathe center, and the pip on the end is for making a tiny pocket to hold lubricating oil for the center.
They aren't intended as an acurate stating drill for a normal hole (even if they do a good enough job of it). For that, you would use a spotting drill or stub drill. Those have long shanks and short flutes so they stay rigid and a split-point grind so they don't wander.

 

[brightspark]

They also break easily

they only break if u force them all the way in without backing off every few seconds to clear the swarf away also best to use cutting fluid

 

[langy]

Thats what i meant, The inexperienced person would probably treat them like a drill.

they only break if u force them all the way in without backing off every few seconds to clear the swarf away also best to use cutting fluid