Drill bit problem

[HackMax]

I usually order a drill bit or 2 when I place an order with Enco so I got a drill bit from enco the other day and figured I'd use that instead of this cheap Chinese drill bit I have been using in the past. The drill bit is just a general porpose hss 3/16" bit. So I have my settings at peck drilling at .1" step down and z speed of 2" per minute. I had the spindle speed at around 1200 rpm. My Chinese drill bit is supposed to be HSS with cobalt plating. It goes through the 6061 aluminum like butter at this setting but this USA HSS drill bit didn't like it at all. Why not?

Thanks,

Rick

[John Welden]

Not sure what the problem is, but you should be able to go a lot faster than 2 ipm. You're doing a lot of rubbing at that slow of feed.

Think about getting stub length or sometimes called screw machine length drill bits. If you don't need the extra length of the jobber, the stubs will perform a lot better.

[HackMax]

Originally Posted by John Welden Not sure what the problem is, but you should be able to go a lot faster than 2 ipm. You're doing a lot of rubbing at that slow of feed. Think about getting stub length or sometimes called screw machine length drill bits. If you don't need the extra length of the jobber, the stubs will perform a lot better.

Thanks for the tip. I always find myself wanting a shorter bit for several reasons. I think I will order short ones next time. I just don't know what's up with this bit. It was very sharp when I chucked it up but it was going in the aluminum like the chisels on the tip weren't cut right - as if there was no lip angle. I'll have to get with Enco and see what the deal is. It was a cheap bit but my concern is I no longer have a backup bit and to get another I have to place an order.

Rick

[Bubba]

Not sure, maybe just lighting, but the bit on the right looks like the flue is the wrong way for the first turn and then the correct way the rest of the bit. In other words, it look like a left hand drill at the tip?

Maybe I am just crazy:})

[HackMax]

Originally Posted by Bubba Not sure, maybe just lighting, but the bit on the right looks like the flue is the wrong way for the first turn and then the correct way the rest of the bit. In other words, it look like a left hand drill at the tip? Maybe I am just crazy:})

LOL the one on the right is the one that actually looked like the one on the left before I used it. It had absolutely little or no cutting ability. That twisting is from the bit heating up and bending the other way.

Rick

[John Welden]

Originally Posted by Bubba Not sure, maybe just lighting, but the bit on the right looks like the flue is the wrong way for the first turn and then the correct way the rest of the bit. In other words, it look like a left hand drill at the tip? Maybe I am just crazy:})

I didn't really look at the bits the first time.

[John Welden]

This has got to be a joke.

[HackMax]

Originally Posted by John Welden This has got to be a joke.

Not a joke. This really happened today. I cant figure it myself which is why I posted it.

Rick

[Mcgyver]

unless you got it red hot, hardened HSS wouldn't twist like that - it would break. my guess is somehow that one didnt make through the heat treatment department which would explain both why it could be bent like that and why i didn't cut. you didnt notice any fault with cutting geometry?

[HackMax]

Originally Posted by Mcgyver unless you got it red hot, hardened HSS wouldn't twist like that - it would break. my guess is somehow that one didnt make through the heat treatment department which would explain both why it could be bent like that and why i didn't cut. you didnt notice any fault with cutting geometry?

No it looked fine to me and was sharp too.

[Matt@RFR]

Originally Posted by HackMax I got a drill bit from enco the other day and figured I'd use that instead of this cheap Chinese drill bit I have been using in the past.

Rick, you probably found the problem right there. You may have stepped up from Chinese junk to US junk. Buy a brand name drill and you'll be amazed at how well they work over what you're using now. It's worth the extra money.

[HackMax]

Originally Posted by Matt@RFR Rick, you probably found the problem right there. You may have stepped up from Chinese junk to US junk. Buy a brand name drill and you'll be amazed at how well they work over what you're using now. It's worth the extra money.

Actually this Chinese drill bit is pretty good cuts straight and fast. I just wanted a backup bit just in case i screw up. (been happening a lot lately) I just chucked in the new bit to see how it would do. I didn't expect any difference. I did contact Enco and they refunded my money. I ordered some better quality bits today, a short one and a jobber size. My bandsaw blade (more US junk) broke today too so I ordered 3 of those. This was a new blade also I think I got to use it 4 times in all. Things are just going the wrong way lately.

I always say if you can throw on a shirt in the dark and not have it on backwards then you are going to have good luck - my shirts have been backwards for a long time now.

Rick