Drill Bits????????????????

[mototraxtech]

I am looking at getting some new drill bits for aluminum. I currently am using some value cobalt bits from MSC. Its a 29pc 135 degree set. Now I must say they cut through stainless like butter(so to speak) and do a really good job but when I put them up to some 6061 aluminum they are terrible. They cut slow and always get built up and I have to pull the entire bit out and clean it about 10 times on a 2" hole. So I figured I would get some HSS 118 degree bits for aluminum which is MOST of what I bore into.

Now the first question to you experts is am I looking for the right cure. Is my drill bit figuring correctly in that I need the sharper angle for the softer material.

Also which bits to buy. I have searched high and low to find them and they range from $40 for 115pc china set to $800 for the same kit made but a top dog american company. So what ones to buy. Currently I have my eyes set on a 29pc set made by hertel that is like $90 but that seems like alot of cash for drill bits. So any ideas on some decent bits.


Oh and just so you know I am thinking about keeping the lathe(for now at least) but remember it is ALWAYS for sale. As with anything I own its all for sale for the right price!


Thanks!

 

[mossyoak]

Don't bother with new drill bits. Just flood the hole with oil. Or peck drill faster

 

[mototraxtech]

well I use alot of fluid and I cant peck very fast at all because my tail stock does not have a plunge lever on it. You can only turn the handle.

 

[65535]

Just go back and forth with the wheel as you drill, don't need to pull it all the way out as long as lubricant is still reaching the cutting face and chips are coming out and not binding.

Also sharpen your bits, that is always helpful.

 

[precisionworks]

You may want to try a parabolic fluted drill, like the Guhring GT50: http://www.guhring.com/PS/Tools.aspx?Type=GT50

More flute clearance for chips (to help eliminate packing), less flute contact to keep down the buildup of heat. Usually not available in sets, but worth the money if you need just a few specific sizes.

a 29pc set made by hertel

Hertel drill bits are a great buy, especially when "sale" priced (which happens frequently). Made in the USA, nicely ground, resharpen well, etc. My letter-number-fraction set cost only $120 & gets frequent use ... and I have no complaints. But don't expect them to give performance comparable to the parabolic, which is designed especially for gummy materials like aluminum.

 

[mototraxtech]

those bits look pretty nice but I count find prices or sizes. I clicked on the lower link and and pdf came up and everything was in mm. If the price was right they would work well as I only need 6 or so different bits everything else I could just use the cobalt.

 

[precisionworks]

I could not find prices or sizes

MSC is a stocking distributor.

Guhring GT50:

Item #85772168, 1/4", $21.85

Item #85772242, 3/8", $38.09

Most fractional, letter, number & metric sizes are available from Guhring.

MSC also sells their AccuPro line & claims good results. Pricing is quite a bit less

AccuPro parabolic for non ferrous:

Item 02372159, 1/4", $10.99

Item 02372720, 3/8", $14.99

 

[precisionworks]

The AccuPro drills are listed on the bottom of page 80 of the new MSC online catalog. They show fractional only.http://www1.mscdirect.com/CGI/NNPDF...522372&PMITEM=85744167&PMCTLG=00&PMT4TP=*LTIP

 

[bstrickler]

I had great luck with 118 degree bits on aluminum. Those were cutting through aluminum like butter. Didn't even bother with lube. Wasn't even a quality bit. Was just a rusty one laying around in the tool box. A 90 degree bit would probably be your best bet for drilling right through aluminum.

~Brian

 

[combinatorix]

For the small-time machinist, I don't think aluminum should ever be forcing you to buying specialty tooling. Try a 118 degree (standard) bit first. Any sharp, decent quality HSS bit should be perfectly satisfactory. If you're still having problems, try varying your spindle speed.

Lastly - if the bits are dull or cut slowly - this can sometimes be solved with some aggressiveness and elbow grease. A dull bit will usually go through a part better if you drill faster and don't let it rub for so long (generating heat and your built up edge). It won't give you comfortable feeling, but if your machine has the horsepower, you will probably spin the piece or the drill bit before anything breaks (unless it's a tiny drill bit, which are always easy to break).

 

[Bruceter]

I like bright finish bits for aluminum as opposed to cobalt or black oxide bits.
It sounds to me like your speed may be off, what size hole are you drilling and how fast are you turning the part? In a lathe where the drill is horizontal, a slower spiral bit will get the chips out of the hole faster than a faster spiral bit.

Bruceter

 

[Rothrandir]

I purchased sets of Precision Twist drill bits (letter, number, and fractional sizes) years ago from J&L industrial and what used to be their overstock zone. Very good price on the sets (over half off if I recall) and they are nice drills. All screw machine type (135degree split point, short)
From then on I've always purchased Precision Twist any time I needed bits, but last week I ordered about $150 worth of bits (several bits each in several different sizes for a titanium job), and some of the bits came with a very poor edge. One of them had a chattery, uneven surface on the front, and several others had chips in the actual cutting edge. They required about 10-20% greater force to push through the material than the previous bits I was using (according to the loadmeter on my lathe). I would have sent them back, except it was a real rush job and that wasn't an option.
I seem to recall something about Precision Twist moving production to China recently, can anyone confirm that?

 

[Bruceter]

Precision Twist brand drills are no longer made in the US. They have one factory in France and another in Brazil.

Bruceter

 

[mototraxtech]

Thats good to know because they are still the highest cost bits on the market and they dont even make them here. So I think I will either go with the hertel or made in usa. I have tried MANY different speeds and amount of force and some work better But not nearly enough. The cobalt bits seem to be to sticky for the aluminum to come out very well and so I think I will get some bright finish screw length bits.



EDIT: Note the highest but up there!

 

[mototraxtech]

Ok so I am pretty sure i will be getting some HSS bright finish bits so now I need to decide between jobber and screw machine. Im thing screw machine as they would be more rigid and the only time I need anything very long is when I am going to use a boring bar. Which I could just use the cobalt jobbers I have now.

What do you guys use!

 

[wquiles]

I purchased sets of Precision Twist drill bits (letter, number, and fractional sizes) years ago from J&L industrial and what used to be their overstock zone. Very good price on the sets (over half off if I recall) and they are nice drills. All screw machine type (135degree split point, short)
From then on I've always purchased Precision Twist any time I needed bits, but last week I ordered about $150 worth of bits (several bits each in several different sizes for a titanium job), and some of the bits came with a very poor edge. One of them had a chattery, uneven surface on the front, and several others had chips in the actual cutting edge. They required about 10-20% greater force to push through the material than the previous bits I was using (according to the loadmeter on my lathe). I would have sent them back, except it was a real rush job and that wasn't an option.
I seem to recall something about Precision Twist moving production to China recently, can anyone confirm that?

Good information to have - thanks. I too have been using PT drills, but so far they have been the good/old type.

 

[RADDWURX]

I have been using a set from -don't laugh- harbor freight, a 118 bit set 135deg. split point coated they were on sale for 39.00 or so. I've had no problem with them for most jobs - they are jobber length- if i need something stubby i usually get cobalt.

I will for sure buy another set of harbor freight when the time comes they have worked fine for me