drill bits

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Greetings,
Mr. ps. I tend to agree with the view of the "machinists" as I've never had much, if any success with Easy-Outs. Haven't used them that much so I guess that's why I can't recall ever breaking one. Just the fear of such a breakage keeps me shy of them.

There are a bunch of different techniques to remove a broken stud/bolt but the usual awkward location in an ER usually limits what one is able to employ. Given the sometimes limited space to swing a hammer to center punch, limited visibility (NOT helped at all by failing eyesight) and small selection of the "best" tools makes a simple repair turn into an OMG! crapshoot. BIG difference between working on a well lit bench and hanging upside down while trying to prevent oneself from falling into the bilge while wielding a hammer/punch/drill AND holding a light in your teeth.

The BEST, by far, technique for extraction of broken/seized bits is heat via a torch but again, if you're working with a casting (block/pump housing) you are limited by the damage that excessive heat can do to above mentioned block/pump housing etc.

I feel for ya brother...

giphy.gif
 
psneeld said:
Sheer torque reversing the bolt...

Many posts from machinists are not favorable to easy outs....they are saying if a left handed drill doesn't do it, chances are it's not coming out with an easy out either.
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They are correct. Have never used an easy out for your application. Drill 50% of the center out and then switch to a left hand twist at 75% size. If that don't do it either retap or helicoil as needed. Each job is a bit different.
 
I mostly use "triumph" brand HSS drill bits, even on Stainless. If I have to drill something that I know has been hardened, I will use a solid carbide drill bit. When drilling Stainless Steel it is most important to use lower speed and HIGH pressure as high speed will work harden the Stainless. Another option to a broken bolt that is proud or flush, is to plug weld a nut onto the broken bolt, let cool and back out with a wrench.
 
RT Firefly said:
Greetings,
Mr. ps. I tend to agree with the view of the "machinists" as I've never had much, if any success with Easy-Outs. Haven't used them that much so I guess that's why I can't recall ever breaking one. Just the fear of such a breakage keeps me shy of them.

There are a bunch of different techniques to remove a broken stud/bolt but the usual awkward location in an ER usually limits what one is able to employ. Given the sometimes limited space to swing a hammer to center punch, limited visibility (NOT helped at all by failing eyesight) and small selection of the "best" tools makes a simple repair turn into an OMG! crapshoot. BIG difference between working on a well lit bench and hanging upside down while trying to prevent oneself from falling into the bilge while wielding a hammer/punch/drill AND holding a light in your teeth.

The BEST, by far, technique for extraction of broken/seized bits is heat via a torch but again, if you're working with a casting (block/pump housing) you are limited by the damage that excessive heat can do to above mentioned block/pump housing etc.

I feel for ya brother...

giphy.gif
Click to expand...

Mr RTF one day I knew a women who... No ok just forget about that this is not the right place :rofl:
 
psneeld said:
Parks...got any left handed sets too?

Maybe when I stop long enough say at Ft Pierce I may be interested.....or when passing through your area in early march.
Click to expand...

They make left hand bits but I don't stock them. Maybe I should. They also make an interesting screw extractor that I recently put in stock but haven't tried yet.
Catalog
Page 113
 
RT Firefly said:
Greetings,
Mr. ps. I tend to agree with the view of the "machinists" as I've never had much, if any success with Easy-Outs. Haven't used them that much so I guess that's why I can't recall ever breaking one. Just the fear of such a breakage keeps me shy of them.

There are a bunch of different techniques to remove a broken stud/bolt but the usual awkward location in an ER usually limits what one is able to employ. Given the sometimes limited space to swing a hammer to center punch, limited visibility (NOT helped at all by failing eyesight) and small selection of the "best" tools makes a simple repair turn into an OMG! crapshoot. BIG difference between working on a well lit bench and hanging upside down while trying to prevent oneself from falling into the bilge while wielding a hammer/punch/drill AND holding a light in your teeth.

The BEST, by far, technique for extraction of broken/seized bits is heat via a torch but again, if you're working with a casting (block/pump housing) you are limited by the damage that excessive heat can do to above mentioned block/pump housing etc.

I feel for ya brother...

giphy.gif
Click to expand...



https://m.lowes.com/pd/BernzOmatic-..._clickID=ab65fba9-27c7-4678-8506-25b4351585dc

A friend of mine has had good luck with this torch at under $30
 
gaston said:
Lubrication Lubrication Lubrication Lubrication

The right Lubrication when drilling SS or any other metal is critical for both cooling and friction reduction. Dont just use any oil sitting around the workshop and expect it to cool and Lubricate the drill bit .
As RT would say the correct Lubrication is good for both man and machine :facepalm:

$_57.JPG
Click to expand...

I added a stiffening base to my davits. I tried all different bits, but when I added a good quality lube, the hardness of the bit no longer made a lot of difference. With proper lube, the task went from impossible to cutting like through butter. This was through 1/4" SS plate.
 
Funny timing on this thread, having just broken off a 5/16" tap on a piece of 1/2" 316 stainless plate I was tapping for my down riggers. The u-tube videos I could find recommended tungsten bits, I tried cobalt and it wouldn't touch the core of the tap. The video had a guy drilling holes right through a HSS hardened drill bit all up and down the bit length.

I got mine out by having a welder TIG a stud onto the broken tap and then rocked it out with a pair of needle nosed vise grips. The welder cost me $20, a tungsten bit was estimated at $30 and not available locally. My other option was to punch it out and help coil it back down to 5/16" after re-tapping, not my first choice.

I lubed with LPS Tricut, which was recommended by my fabricator, neither HSS or cobalt moved any metal on the tap.
 
My experience:

Drill-doctor highly recommended. Does a good job of sharpening twist drill bits.

Using plenty of oil to take the heat away is essential.

When drilling stainless, always use a sharp bit and push hard enough to keep the chip going. Too light and the bit will stop cutting and start heating. The work piece will then harden.

A center punched dimple or pilot hole is essential to start the hole in the right place.

Drilling a big hole by going up in one-drill-size increments tends to make the drill "chatter" (walk around in the hole) because only the corners of the cutting edges are touching the work piece - nothing to keep it centered. This is a recipe for breaking bits and chewing up the hole. Drill (say) a 1/8" pilot hole then use significantly larger bit - the final size if possible. This way most of the drill is cutting metal, not just the corners. Poor explanation, but hope the gist is clear.

If drilling thin plate results in somewhat "square " holes, then drill through four thicknesses of denim or other hard cloth. Here is a link to a YouTube video https://youtu.be/4HOxfZKIZQk
 
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[QUOTEWhen drilling stainless, always use a sharp bit and push hard enough to keep the chip going. Too light and the bit will stop cutting and start heating. The work piece will then harden.
][/QUOTE]

Yes it's the chip that should be taking the heat away.
You want good sized chips, not dust.

Re easy outs....I have a friend who has probably 95% success with easy outs. He was a factory maintenance foreman in his career. He had lots of practice (and patience).
 
Lou_tribal said:
About drilling a metal, younstart small and increase the size of your bit all the way till your desired sized. A good way for drilling metal plates are staged bits don't exactly know the name in English but these are conical bits that increase hole diameter with depth.
Fot extracting a stuck or broken bolt, you first drill a hole in your bolt that you stuck your LH bits in it with one or two hammer stoke then use ur drill.
I never ckecked for any documentation about it just learned that from elders that knew what they were doing. As an example when my father was at school, at that time they were learning things ranging from electricity to forging and working with metals. This was a time when working experience was more valuable than reading books.
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What you refer to staged bits, I've heard called step bits.
 
A couple thoughts:

If you are going to try an easy out, do NOT break it off. Might be too late for that advice. Carbide bit is harder than the HSS easy out, but centering will be tough. No fun recovering from that.

Cutting fluid like tapmagic is a necessity. I keep a shot glass of the stuff and an acid brush. Keep bit damp with it, if you see vapor back off, you are cutting to fast or too hard or too dull.

I do not buy expensive bits. TiN coating seems like BS to me, never seen any better cutting performance with that. I think they sell because of the pretty shiny color. Standard HSS, but I try to buy them from an industrial supply house instead of Home Depot. A little more bucks, but quality is better. Especially taps. Cheap taps are evil and gets you in the same situation as busted easy outs.

There should be no stainless bolts holding engine structure, especially something that vibes like an alternator bracket. SS is low strength compared to normal SAE grade 5 or 8. SS can also set up galvanic activity in the threads that a gr5 or 8 would not.

SS bolts often referred to as "butter bolts".
 
I can't help but wonder if step bits are absolutely wrong for metals that work harden? I think each step would prepare the metal to be harder for the next step. They're probably dandy for ordinary, thin metals.
 
I have always used drill bits by Starrett, nothing else comes close ! Prefer the shorter ones ( jobber bits, as we call them in the trade )
For lube / tapping etc. nothing beats Croma Tap. Back in the day, they had Cromatap that was clear ( even smelled nice ) now they got the oily looking stuff but it still works great. Just my .02 CAD .... :) Frank B.
 
DHeckrotte said:
I can't help but wonder if step bits are absolutely wrong for metals that work harden? I think each step would prepare the metal to be harder for the next step. They're probably dandy for ordinary, thin metals.
Click to expand...


I totally agree with you on the step bits ....... but pricey ! FB
 
Back in the olden days, before I could afford a torque wrench, drill sharpener, or HS drill bits, I snapped my share of bolts, drill bits, EZ outs, etc. Now that I'm older and wiser, I know when to back off but dealing with a bolt that has been living in a salt environment for 30+ years and is just about welded into the block remains challenging.

I just keep going up in sizes until I hit the threads. Tap in a screwdriver and keep my fingers crossed. I now use 4 or 5 drops of 3-1 oil as cutting fluid instead of 2 or 3 :)
I may use a hair dryer to gently warm everything up and then drench the bolt in PB Blaster.

I am very generous with blue loctite during reassembly.
 
Good thread, learnt a lot.

I'm not a machinist but can appreciate the skills and tools needed.

I've had pretty good luck getting the job done, but limited experience with heavy stuff. As an aircraft mechanic, most of the stuff I do is small, 1/4 in sockets, small parts, sheet metal, etc. Rarely have an issue with a stuck bolt or screw and easy outs work 98% of the time... with perhaps a bit of heat or Kroil (great penetrant). For the big stuff, like engine bolts the same works but need to pull out the 3/8 to 1/2 in drives.

I appreciate the sources mentioned for drill bits... as I'm shopping.

Also working on IOs isn't hard, but did have a challenge with a 10-32 x .750 bolt holding on a tilt switch. Was painfully hard to get out, and let the Kroil soak in a few times. I worked the bolt back and forth with a vise grip and that worked, and then eased it out with a bit on a socket. My boat mechanic friend tried one with his hammer drill and snapped the bolt off......:bang head:

Need a diesel engine to practice on....
 
Lou_tribal said:
About drilling a metal, younstart small and increase the size of your bit all the way till your desired sized. A good way for drilling metal plates are staged bits don't exactly know the name in English but these are conical bits that increase hole diameter with depth.
............
Click to expand...

In the USA, these are called "unibits". They only work well in relatively thin metal, perhaps 1/8" thick or so.
unibit-cobalt-step-drill-483.jpg
 
Working on heavy equipment for over 30 years I've removed hundreds of broken bolts. I've blown some out with a torch and then dress the threads, welded nuts on them, drilled and used a easyout. On yours I think I would cut a slot in it with a die grinder and try a screw driver or new bit and wrench, a worn flat on a screw driver may ruin your 1 chance to remove it.
 
Just to let everyone know, the bolt was broken off half way into the threaded hole so cutting a slot in it would be tricky.

Either way the problem was temporarily resolved a 100 miles back.

I managed to drill enough out with Colbalt bits and a 18V drill, and stick a slightly smaller bolt all the way through with washers and a lock nut.

When I get to Ft Pierce for a month, I will dill it out proper and put a slightly larger, hardened through bolt in the hole.

If I can find a good welder for cheap, maybe I will fill in the hole and re tap....but in all honesty...not sure why through bolts aren't a better idea just because of what happened on the road.
 
Just my two cents...sorry for bumping...

igh speed steel is good for anything from wood to titanium, why titanium you ask...its beacuse the high speed steel takes te heat where carbide will cause work hardening and snap a drill very fast if the piece gets warm. Their are alot fo variables on this one but high speed steel is a great general purpose steel for drilling/milling


Cobalt~ cobalt is a very tough material but extremely brittle and when mixed with HSS it creates a very tough drill second only to carbide good for everything from wood to harder steels

Carbide~ there are many different types of carbide with micrograin carbide being the toughest and couple this with coarbonitrate titanium and other titanium coatings and you have a very formidable drill that is capable of drilling most any material, Concrete drills use carbide tips and hardened steel bodies with the carbide brazed on the body, this provides a very tough drill that can take the pounding and not chip out. Carbide drills are usually 3 times heavier than HSS

Diamond~ Diamond is used for cutting concrete and for holding tight tolerances in high speed machining of aluminum and softer metals, When i was at 3M they actually invented a machine that makes industrial grade diamonds, it was so efficient that GE asked them to stop producing diamonds. The Machine that looks like a alien bomb still sits in a dusty room to this day at 3M's center in Oakdale MN. Diamond or diabide is coated onto drills and adds a very thin layer of diamond buildup that last a long time in abrasive conditions. Diabide cannot take heat and the coating crumbles off when cutting harder metals.....its kind of a bummer we can use diamond on our cutters but cant cut anything hard. Also industrial diamonds are used on concrete blades and are visible by little black dots and raised dots on the blade.

Drills come in many different sizes and qualities with chinese drills leading the pack of cheap disposable drills that dont hold an edge very long, so is true for carbide and cobalt drills, you get what you pay for..usually if you go to JandLindustrial.com theylists all their tools as either import or domestic. Machinists know the difference between import and domestic tooling` Import tooling wears out too fast but is a great substitute when setting up a production job where you may break a tool or 2.

Also drill technology has come a long way, companies likeAllied offer a psade drill that takes a insert made out of micrograin carbide and coated for the application. these drills are sweet but arent for your average consumer. Here is a little info if you are going to sharpen your own drills at home

1. 118 degrees is your standard drill tip angle
2. 135 degrees is usually used on a split point drill where you are not using a center drill to start the hole.
3. Keep in mind the relief on the top of the drill and on the side!!
4. Drills usually are only sharpened 8-10 times in a machine shop as the inner web gets thicker and is tapered the drill looses alot of efficiency
5. Drills are also prone to the side flutes wearing, it is possible to resharpen a drill and it may look good but not leave a good finish in thehole or leave a galled or reduced diameter.
6. Remeber that you can sharpen a drill back to spec but if you spin the drill in your chuck youve probly damaged the shank and the drill will not hold a on center rotation with a damaged shank.

Personally i just use a squirt of WD40 and keep the cutting speeds low. If you can get a nice long spiral chip coming out, your doing well, and the drill is cutting good and you're applying good pressure with good speed. I aim for a 1 inch long chip or so, then back off, then reapply... ie Peck Drilling (making sure to clear chips in between)

good luck with your drills guys and if your hand drilling with a old drill make sure your bracing yourself or slow down at the end of the hole

Just some suggestions and one good video from Youtube, that I hope will help.

 
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same as Brian in post #38 Drill Doctor did work very well for me
 
Quelly, you are correct to refer to those spiral pointy things as drills, not bits. One inserts them in a motor drill or drill press chuck and makes holes.
 
Better yet, would be for you to get a machinist/millwight to show you how to sharpen a drill with just a bench grinder eliminating the fancy-shmansy thingy.
 
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