General question...
What kind of bits do you guys use when drilling out steel bolts?
I don't do a lot of drilling, but my 27" breaker bar has been known to snap a bolt or two.
I use regular HSS bits from crappy tire. They can take quite a while and wander as they start.
Do you guys use titanium coated bits? Cobalt bits? carbide tipped?
I'm pretty sure the coatings just increase the lubricity and thus the life of the bit.
Carbide tipped bits are pricey, but seem like they're made for the job.
What's the best hard steel bit for your money?
I use cobalt or masonry bits. Masonry bits are cheap and work quite well. I am considering investing in a bit sharpener as I go through quite a few bits.
I sell many drill bits. Unless you are work hardening the part your drilling by going too fast for the pressure applied I don't go with the cobalt or carbide. Drilling just steel I like what Drillco has called NITRO mechanics length they are black and bronze with a split point. The split point is great for non pilot hole drilling. If you are drilling a pilot hole with the bits smaller than 1/8" they won't walk all over either as they are split points as well. The only downside to the NITRO is the black tends to be sticky with Aluminum. For all around drill bits that will do Al as well as steel I like the Split point bright finish HSS. They aren't sticky with Al.
To make all drills last I like Tap Magic X-TRA thick. You can dip the bit into the sludge and usually drill about 5 holes before the stuff runs off or is gone. Everybody probably has something similar to it but I like the Tap Magic brand. They also have the runny stuff, but you use 20x as much since it runs off as fast as you pour it on.
You need to punch the center of the bolt and make a little dimple in the metal so the bit doesn't wander
I have a set of left-handed drill bits that I use for broken bolts. Every now and then I get lucky and the drill bit will catch the bolt and spin it out. Also if the bolt is in tight I put a little heat around the broken bolt and then drip some candle wax into the threads. This helps to lube the threads.
All good stuff guys.
I do use cutting oil, but it can be messy. I like the sound of that Tap Magic X-TRA thick. I'll look into that.
I always punch to make a starting dimple, but I find it still wanders on the hardened bolts. Maybe I'm not punching enough, or my bits are too dull
I suspect you get what you pay for...$40 for 100 HSS bits at Tire vs $40 for 13 nitride coated premium grade molybdenum HSS bits.
Perhaps it's time to invest in some serious bits now that I'm getting more adventuresome.
I do have some of those left-handed bolt-out things from Mastercraft. I break them every time I use them though. They might be okay in the wood-shop, but they're not meant for the 18 year old OEM bolts on
my car
I am considering investing in a bit sharpener as I go through quite a few bits.
You don't need a bit sharpener. Bits can be sharpened quite nicely freehand on a bench grinder.
I am considering investing in a bit sharpener as I go through quite a few bits.
You don't need a bit sharpener. Bits can be sharpened quite nicely freehand on a bench grinder.
I've ruined quite a few trying that, but I've also got it perfect and they cut better than new. I guess it takes practice.
I've ruined quite a few trying that, but I've also got it perfect and they cut better than new. I guess it takes practice.
It most certainly does. I was lucky enough to learn how from a machinist with 30+ years of experience. After learning how to properly sharpen bits and knowing what they drill like there are very few things more frustrating than using dull bits.