What did I do wrong? David D. The most obvious possibility is that you hit a piece of rebar, or reinforcing steel. Or maybe you found a cast-iron drainpipe.
If you see a pipe exiting the floor at any point, assume that that's what you're hitting and drill elsewhere. You might think that a bit strong enough to drill through concrete could also handle steel, but a masonry bit's tip and flute geometry are completely different—thicker and blunter, meant to pulverize.
Also, the hammer drill was probably in percussion mode, which simultaneously pounds and drills through concrete, stone, or asphalt. That percussive action broke the bit when you hit steel. Even if you'd switched to rotary mode, it wouldn't have helped. Note this warranty does not cover damage due to misuse, among other things. So, if you want to make sure you can the right tool for the job, let us know and we can help you. Customer Service.
Company Info. News Room. Stay Connected. Broken Bit? Have a Broken Bit? No one means to break the tool, but doing things quickly can often be the culprit. So here are a few things to look for when it comes to broken drill bits. Also by the sound if you drop both on a hard surface - they sound quite different. Even good quality carbon drills are not bad if handled carefully, but HSS is a lot better. For twist drills try a professional tool room supplies place, and as the guys say expect to pay potentially quite a bit more.
Better quality drills tend to be far more precisely sharpened, and to cut much more cleanly. For brad point bits more or less the same applies. Avoid the box stores for anything except rough work although Bosch DIY product while not great is often not too bad , and go specialist for the good stuff. I have one of standard twist drills with the gold coating bought in the UK. Be aware that titanium nitride gold is just a low friction coating.
It's quite likely not even what it claims to be. It's well worth buying a few samples of a premium quality drill, especially in brad point. Just to place yourself in the delicious dilemma of realising just how good and clean cutting a drill bit can be, and why before long you will probably be prepared to pay x5 the price of cheap drills.
I can completely agree with Ian Mayberry on every point he makes. Most of the brands will be garbage but then they go and have Milwaukee, Bosch, and even Dewalt Rotary Hammer Bits that work very well. Hurry up and buy some as Stanley Black and Decker will find a way to screw it up eventually. When you find something they sell that is excellent, they will always turn it into acceptable on the way to turning it into garbage.
If you want a good set of premium grade HSS bits for general use including steel drilling, go to carbideprocessors. Call them if you want to describe your needs and they will bend over backwards to help you out. I always keep a pack on hand and buy them when they sell them for virtually nothing.
Originally Posted by Greg R Bradley. This is the second post I have seen this discussion. I buy Fisch drill bits. Their forstner wave bits are the best out there IMHO. If you want good drill bits, you'll have to pay for them. It all depends what you're cutting with them.
Brad point bits are generally better for woodworking than twist bits. If you're looking for drilling metal, then you'll need a good set of twist drill bits. It is so nice using quality drill bits. You can tell just by looking at them that they're going to drill better. Straight, nice clean edges on the sides as well as the tip , and no burrs. I've seen so many Import drill bits that were full of chips, burrs, and bends -- and they were brand new.
Even the grind on some of them wasn't even centered or symmetrical, so the point was closer to one edge than the other. I'm a big fan of cobalt drill bits. They're a little harder and more heat resistant than regular HSS bits, and do a much better job on tougher metals.
There is a tradeoff between hardness and brittleness, though. Harder bits drill harder metals, but they're more prone to breakage if misused. Low carbon steel bits are less likely to break, but they don't work at all on harder metals, and they are prone to bending. To me, a bent bit is about as useful as a broken one.
My go-to twist drill set I keep in the woodshop toolbox is a Milwaukee Piece cobalt jobber set It's an awesome set, but they don't make it anymore. They're probably outsourcing everything these days too, so I can't really vouch for the new ones.
In my machine shop, I use Precision Twist cobalt drill bits. They're good quality US-made bits.
0コメント