PDA

View Full Version : What did I buy?



tylernt
02-18-2013, 06:06 PM
Was pawing through the used tool section of a local shop and found a little box of hand-ground HSS boring bars. Randomly mixed in was this item:

http://i664.photobucket.com/albums/vv3/tylernt/maybedeadcenter.jpg

Given the dark-gray appearance, heavy weight, and mirror-finish polished pointy end, I thought it might be a solid carbide dead center. It was individually marked $1 so I shrugged and bought it. When I got it home, I found it mildly magnetic, and the point was able to scratch steel very easily.

I know the above picture is the worst one in the world, but... what do you think? Dead center, or something else? If it is a dead center, can I just chuck it in my tailstock Jacobs chuck?

PixMan
02-18-2013, 06:10 PM
Hard to say because I can't see the end too clearly, but it closely resembles a diamond dresser for grinding wheels. Is there a dark thing brazed onto the end?

J. R. Williams
02-18-2013, 06:10 PM
Part of a broken carbide end mill.?

laddy
02-18-2013, 06:16 PM
Dead Center?

Mikey
02-18-2013, 06:27 PM
Punch for an optical center punch?

tylernt
02-18-2013, 06:30 PM
Hard to say because I can't see the end too clearly, but it closely resembles a diamond dresser for grinding wheels. Is there a dark thing brazed onto the end?

There is a second, more obtuse angle near the tip, but it's all one solid piece.

Come to think of it, the included angle is 90, not 60, so maybe it's not a dead center after all?

John Stevenson
02-18-2013, 06:52 PM
It's a left hand version of one of these.

http://www.stevenson-engineers.co.uk/files/maybedeadcenter1.jpg

Zero_Divide
02-18-2013, 06:59 PM
Tips for hardness tester?
Probably carbide as it is also mildly magnetic.
Either way dont use them as center punch.
They will shatter in your hand.

A.K. Boomer
02-18-2013, 07:03 PM
Must be my lucky day ------- SJ - forget the tool fool, i'll give you five pounds for that quarter you have...

can come up with the goods tomorrow morning (after I have my coffee)...

boslab
02-18-2013, 08:02 PM
It's an optical emission spectrometer electrode, should be 1/4" dia with a 90 degree inc point made of 99.99% Tungsten, looks like to me anyway!, mainly as I have a box of them that are too short to be used any more, it should feel quite weighty in your hand.
Mark

Bob Fisher
02-18-2013, 08:18 PM
I know what it isn't, a hardness testing indented. It does , however look like an punch from an optical center punch.Bob.

tylernt
02-18-2013, 08:28 PM
It's an optical emission spectrometer electrode, should be 1/4" dia with a 90 degree inc point made of 99.99% Tungsten, looks like to me anyway!, mainly as I have a box of them that are too short to be used any more, it should feel quite weighty in your hand.
It is quite hefty for something so small.

So, I got to thinking. Since the extreme tip has a slightly larger angle, the tip will not bottom out in a 90 hole. And, I also happen to already have a 90 spotting drill I can use to centerdrill stock. So even if this thing is properly a widget for some other application, I think I can still pervert it into use as a dead center.

It's too short to bottom out in my Jacobs chuck, though. I might need to drop a spacer into the bottom of my chuck to use it, as the steel chuck jaws probably won't be able to keep the carbide from slipping back under tool pressure.

Zero_Divide
02-18-2013, 09:07 PM
I ve heard somwhere regular jacobs chucks run out too much.
If you had one of them hi precission chuchs then that might habe veen a different story

KiddZimaHater
02-18-2013, 09:17 PM
Either way dont use them as center punch.
They will shatter in your hand.
A former co-worker was using an old socket handle, ground to a point, as a punch.
It shattered when he hit it, and he had to have surgery to remove the shrapnel from his hand.

darryl
02-18-2013, 10:25 PM
Looks like a piece of micro-grain carbide to me.

becksmachine
02-18-2013, 10:48 PM
Do they make grinding wheel dressing points without diamonds?

Dave

Dr Stan
02-18-2013, 11:02 PM
Do they make grinding wheel dressing points without diamonds?

Dave

No, but sometimes the diamond falls out or is knocked out.