Sweet

Well done. Getting the drill started in hard stuff is not easy.
I drilled many in old British casings, but it was aluminium.
Also had friends at air New Zealand in the machine shop. Some good aluminium welders there. Probably long enough ago that no one will get in trouble.

All I did today was remove the two petcocks from the tank on Laramie. Larry had messed up the phillips head screws.

Unkle Crusty*

 

yes yes, finally learning something... get the start hole centered first... I find free handed, that the smaller the drill you start with, the easier it is to get centered. My problem is removing enough screw to get a small easyout in it. 6mm holes are very small!

 

Using a lefthanded drill bit will often remove the screw before you even have to resort to an extractor. Most industrial suppliers carry them and you only need one or two sizes, not a full set.

 

Those are used a lot South of the equator, right?
:wink:

 

That's good thinking Slum, and a great idea!

I would have likely turned a centering adapter of some sort on the lathe, and taken 12 times as long as I needed to get the job done.

 

Just don't break an extractor off in the hole, if you do then it gets 'interesting'

Been there WAY too many times.

 

The worst part of having a job shop is the endless opportunity of removing broken bolts AFTER someone else has botched the job first. :frown:

 

Actually I don't mind doing it for someone else. I hate doing my own cause I should know better. Know what I mean?

 

Yeah, I know what you mean... slapped myself many a time for breaking a tap because I got in a hurry.

The problem with doing it for customers is charging for the amount time it sometimes takes. Just a couple of days ago one came in... an aluminum block with a bolt broken down in the hole. They had tried to drill it and broke the bit off. The bit was half in the broken bolt and half in the block acting like a key locking the bolt so no chance of it turning. THEN they tried to weld onto the broken bolt and were unsuccessful other than in making the end of the bolt HARD. Got it out but it was a bear and took an hour and a half of shop time.

 

Sounds like something my cousins would do. Won't stop until it's nearly impossible. Stuff like that I wouldn't hesitate to charge triple your time. There isn't a glut of people that can salvage what idiots do. I'll work on it for others but only friends. And they know I won't charge but will expect a dinner for me and the wife. It might take me a week too. I just don't rush. I rush when it's my stuff. Stupid fool!!!

 

I never thought of using a masonry bit. I do use tons of little grinding stones. Do you put a more or less aggressive cutting edge on them? Not a lot of carbide to work with though in the bits I've seen. And with or without hammer mode if that plays a roll?

 

Hog, masonry bits don't have a sharp angle which gives them more strength for the job they are intended to do. Problem is they don't really have a sharp edge either because it won't last drilling concrete, so if they aren't sharpened they tend to skate rather than bite on steel. Keep the angle flat with just enough relief to let it cut and it will last much longer. Do NOT use hammer mode when drilling steel... that's only for bricks and concrete!

You're right about there not being much carbide to work with. I use 'em to drill hardened steel, like car springs, etc. but you have to be careful when going through. That's when the carbide will shatter if you let it grab. Power feed on a drill comes in real handy for that work!

The import masonry bits aren't much good either, tending to break off around the carbide tip. Use good quality USA made masonry bits... they are still much cheaper than carbide twist drills and work well.

 

Impressive descriptions, thank you guys for sharing.

 

Never thought of using masonry bits, great tip Doc.

 

As far as recommending a good quality masonry drill bit, Tapcon makes really good ones that seem to outlast all others in drilling masonry. Would that be your recommendation, Metaldoc?

 

Or Irwin. I do wonder if Tapcon isn't the true supplier for theirs though.

 

Funny, I thought of this thread today at work, and learned a new trick as well that I want to share.

I had to remove a broken bolt from a threaded hole today on one of our shop tools before we could use it, ( a bench mounted pipe vise, somehow 'the phantom' managed to break the bolts that hold the jaw on the base?), anyway I tried the 'centerpunch it around until it unscrews' method, that failed, my next trick was the 'drill it out with a left handed drill bit, maybe it will come right out'.

I was looking through the drawer of left handed bits to find an appropriate one when the guy I was working with said "wait, save those for when we really need them, I have an easier way for this".

He turned the piece over (the holes in the jaw were through tapped all the way), and said, just drill with a regular bit from that side! I was dumbfounded..so obvious, but it never occurred to me! A bonus was the nice smooth end of the bolt was easy to start drilling into instead of the broken, abused end. The bolt came out when I was less than 1/2 inch into it, and all was well, and I added something to my bag of tricks.

 

He turned the piece over (the holes in the jaw were through tapped all the way), and said, just drill with a regular bit from that side! I was dumbfounded..so obvious, but it never occurred to me! A bonus was the nice smooth end of the bolt was easy to start drilling into instead of the broken, abused end. The bolt came out when I was less than 1/2 inch into it, and all was well, and I added something to my bag of tricks.

Good for you! :thumbsup:

I've done that as well, even drilled in from the back side blind when it was possible to measure and lay out the hole accurately... then weld the hole closed.

Another trick... if you don't have a left handed drill bit, reverse grind the cutting edge so it will grab when running backwards. If the bolt doesn't come right out, you'll have to clean the hole more often since the flutes won't be feeding the chips out. Blowing some air in the hole will help clear the chips.

 

Mirror image.

One fly said to the other as they were walking across a mirror: Well that's one way of looking at it.

Unkle Crusty*