I'm sure I got a short.

[Curious Hound]

Those are pilot point bits. They have a pilot ground into their shape. They're supposed to be ok. If they work, that's awesome. I have a bunch of those in smaller sizes. But I dont like them for metal cutting. It's just a personal preference.

 

[alwaysFlOoReD]

Well I had to drop 1 of my classes before it started today.
Hopefully I will be able to take it next 1/4 or semester or whatever they call it.
I was able to start 1 of my classes today however so that is a good thing.

I was also able to take some pictures of 2 of my drill bits today as well.
I couldn't find the other 2 drill bits however.
My brother moved the tools I was using on my truck around so I will have to ask him where he put them.

So here is pictures of the 3/8 bit I've been using and the new 7/16 bit that I haven't used yet.
View attachment 128280View attachment 128281View attachment 128284
Notice the bottom of the package says COBALT on it.
From what I understand Cobalt is supposed to be the strongest steel that's made.
Also notice the tips are not like normal drill bits. It has a step down to it.

Cobalt is a harder steel. There are harder but not something you'll find at a lumberyard.
The tip has a pilot bit built in, so normally wouldn't need to drill a small hole with a pilot bit like we've said you should do.
I'm not sure why you would be dulling the bits, could be no cutting fluid, or not enough pressure, or too much pressure. The shwarf that comes out of the hole can take different forms depending what you're drilling. Regular mild steel should come out in one long curlicue similar to curled Xmas tinsel. You would pull back slightly while drilling every second or two to break the shwarf so it doesn't tangle up on something or cut your finger off.
Cast iron doesn't make the curlicue, it will already be small broken pieces.
If you're drilling into a bolt or stud, it could be a higher grade steel which may be why the bit dulls quick.
I learned a why heating a bolt or stud works for loosening a few weeks ago. When heated metal expands. The metal surrounding the hole doesn't expand. So the bolt can only expand in the direction of the opening. When it cools it shrinks in all directions, making it slightly smaller diameter than before. So now there is room and it will turn.

 

[ShhhhhDougsHere]

1st I was not using any kind of cutting fluid at all. So I didn't have anything to keep the bit cooled.

2nd I was keeping constant hard pressure and not letting up at all.

3rd I'm trying to drill out exhaust manifold to exhaust pipe bolts or studs which are a harder metal to start with. Beings they are bolts. And have been through many many many hot and cool cycles in their lifetime.

At this point I'm wondering if my bits really are dull or if I just think they are because the forward progress seems to have come to a halt.

They seemed to cut really well at the start and then it just seemed like I was not getting any more forward movement.

I was getting very very very fine metal shavings. Smaller than sand even. And then it was like the bit was just setting and spinning and not cutting.

Or maybe it was cutting and it was just so fine I couldn't tell the difference.

 

[Curious Hound]

They are probably dull. No cutting oil, plus continuous pushing without letting the bit cool, becomes a bad situation for cutting tools. Another factor is rotational speed. But at the size you are drilling, an average drill shouldn't be developing too much speed. If you get into a machining training class, you will learn about "feeds and speeds". That refers to how fast the cutting edges is moving and how fast you are "feeding" it or pushing it into the material. Important things to learn for drilling operations, lathe work and milling.

 

[alwaysFlOoReD]

They are probably dull. No cutting oil, plus continuous pushing without letting the bit cool, becomes a bad situation for cutting tools. Another factor is rotational speed. But at the size you are drilling, an average drill shouldn't be developing too much speed. If you get into a machining training class, you will learn about "feeds and speeds". That refers to how fast the cutting edges is moving and how fast you are "feeding" it or pushing it into the material. Important things to learn for drilling operations, lathe work and milling.

I agree on being dull.

 

[ShhhhhDougsHere]

Milling, drilling and lathing is the class I started today.
It's a 16 class course.
The title of the class is 25.SU.CAM1109.101 FUND OF TOOL & MACHINING.

^ that's a screenshot of the webpage I have to go to, to read the PowerPoints for the class.
To help me do some of the class work because I don't have a book yet.
I should get a book on Wednesday.

 

[ShhhhhDougsHere]

I know they make drill bit sharpeners.
But do they make drill bit sharpeners for the type of drill bits I have?

I paid almost $86.00 for the 4 bits I have I can't afford to just buy a new bit everytime I dull one.

 

[Curious Hound]

It's easier to just sharpen them to a normal point. Yes. All you need is a good bench grinder and some practice. A drill point gauge is helpful. There are videos teaching how to do it.

 

[ShhhhhDougsHere]

Okay thank you both @Curious Hound & @alwaysFlOoReD for the help and encouragement you have given me today.
And thanks to everyone else for the help and encouragement they have given me in the past as well.

I got to go home for tonight.
I'll check back in sometime tomorrow.
Thanks everyone.

 

[SenorNoob]

I've never been able to sharpen a drill bit. Never had one of those nifty gauges either. Any time I was able to get a bit sharp (even a veteran machinist said it looked good to him) it didn't last but a few seconds. No idea what I did wrong. It was used in a variable speed mag drill. So speed and feed should've been pretty consistent. Looking back maybe I got the bit too hot while sharpening?

 

[alwaysFlOoReD]

I found this on another forum. Maybe it works for you. I've never bought any of these...


6$ 16 pc (note; only the 1st row of bits is cobalt; also metric, vendor also has an 8$ metric w/steel index for 10% off when combined):

https://www.amazon.com/gp/product/B0DGS5D75H/?tag=atomicindus08-20
8$ 13 pc; imeprial:

https://www.amazon.com/gp/product/B0BDKR2KFZ/?tag=atomicindus08-20
9$ 13 pc ruggedized case:

https://www.amazon.com/gp/product/B0DHC23P4C/?tag=atomicindus08-20
another imperial:

https://www.amazon.com/gp/product/B0C4H5F2H7/?tag=atomicindus08-20
10$ 13 pc w/steel index & 10% coupon; imperial:

https://www.amazon.com/gp/product/B0DHD2SFK8/?tag=atomicindus08-20
Another imperial steel index:

https://www.amazon.com/gp/product/B0CSW66WHV/?tag=atomicindus08-20

 

[Curious Hound]

I found this on another forum. Maybe it works for you. I've never bought any of these...


6$ 16 pc (note; only the 1st row of bits is cobalt; also metric, vendor also has an 8$ metric w/steel index for 10% off when combined):

https://www.amazon.com/gp/product/B0DGS5D75H/?tag=atomicindus08-20
8$ 13 pc; imeprial:

https://www.amazon.com/gp/product/B0BDKR2KFZ/?tag=atomicindus08-20
9$ 13 pc ruggedized case:

https://www.amazon.com/gp/product/B0DHC23P4C/?tag=atomicindus08-20
another imperial:

https://www.amazon.com/gp/product/B0C4H5F2H7/?tag=atomicindus08-20
10$ 13 pc w/steel index & 10% coupon; imperial:

https://www.amazon.com/gp/product/B0DHD2SFK8/?tag=atomicindus08-20
Another imperial steel index:

https://www.amazon.com/gp/product/B0CSW66WHV/?tag=atomicindus08-20

Those look like some good, affordable ways to get started.

I finally got tired of my drills being scattered. I put them all in drawers, except for one travel set and my number and letter sets.

These empty indexes are available if anyone wants to pay shipping.

 

[ShhhhhDougsHere]

Thanks @alwaysFlOoReD for the drill bit look up.
Those do look like some good bits for some good prices.

I went to the all famous
" Harbor Freight "
and bought their $20.00 drill bit set.

I'm going to take the Cobalt bits I now have to class with me tomorrow.
And see if I can get the teacher/instructor to show me how to sharpen them properly.

The way I see it, the worst he can say is,
" I don't got time. ".
Or
" That ain't what this class is for. ".
Or some s*** like that.

 

[Curious Hound]

I got a cheap set of bits from Harbor Freight years ago and many of them were ground off-center. Points and cutting edges were centered. But the flutes/webs were off-center.

 

[ShhhhhDougsHere]

I truly believe that @Curious Hound .