Drill bits

I've been a machinist, toolmaker, moldmaker for 24yrs.. I bought 2 import drill indexes about 20 years ago, I took one home, I left one at work in my box.. I still have both, sure a few of the smaller drills broke and also went missing, but I still have quite a few of those drills still left.. they were good quality taiwan made drills, not near as good usa made drills, but they worked fine for the money..

When I need cobalt at home, which is usually not often, maybe half a dozen times, I borrow one from work :huh:

depending what you plan on doing at home, I'm with the others, buy a decent set of hss bits, and just individual cobalt drills as you might need them..
You might even buy a couple extra cobalt bits when you get the hss drill set, the cobalt drills you might need at some point in time, such as #7 drill for tapping 1/4-20 holes, F for tapping 5/16-18, 5/16 used to tap 3/8-16, 27/64 for 1/2-13, also get the 1/32 clearance sizes for common bolt sizes such as 9/32, 11/32,13/32,17/32 the 17/32 will also be drill size for 5/8-11 tap..

let us know what you decide..


also, you might look around for auctions, that is the place to buy tooling..
 
I'm weird about drill bits. I believe having the cheapest POS on earth in hand when you need it beats the snot out of plans to buy a good one. One of the indexes that sits out on the workbench is a chinese cheapy Alpha # fractional. Really I don't think I could have bought only the index holder for what I paid on sale. After several years it is amazing how many of the gold doodoo is still in there. Off the top OMH #7 (1/4 20) 1/4 5/16 (3/8 16) 3/8" 1/2" have been relaced, several others. Honest, drills aren't worth a childs ransom. I say buy a set in your budget and replace the drills you wear with better ones. Hopefully 10yrs from now you'll look in the index and be surprised how few you really used. Sure as you buy an expensive index today you'll get one for 25$ a a yard sale next week!

Steve
 
Ok, I am leaning a little more back to the HSS now. On the carbide processors website, I am undecided though on rather to get the Thunderbit HSS for $435.91 or still spend the little extra for the cobalt for $639.40.

http://www.carbideprocessors.com/tr...t-drill-sets/jobber-length-combination-sizes/

Or I am looking at the Norseman for $466.24.

http://www.fastenal.com/web/products/detail.ex?sku=0311269

I am not set on buying from any one company in particular, these are just for a reference.

One part that I know I will be making a few hundred of will require to hole to be drilled for a 5/16”-24 thread, which is a requires a “I” letter drill. The metal for that 5/16”-24 thread part will be mostly 440c and a few out of titanium. As far as most of the projects I will be doing will be out of AL, SS, and various types of steel, some hardened some not.

Also, I am looking for some drills that I can use to drill out broken bolts with. I will drill them on a drill press or a mill when possible, but what drills would be best for use in a hand drill for drilling out bolts?

Thanks,
Jonathan
 
One thing to note is avoid parabolic flutes if you intend to resharpen yourself as they are a pain.

Most of my indexes started out as medium quality and much used drills get replaced with cobalt.

For drilling out bolts/studs with a drill motor it is hard to beat L handed bits often they'll just back right out when you near the bottom.

Steve
 
swatson144 said:
One thing to note is avoid parabolic flutes if you intend to resharpen yourself as they are a pain.

Most of my indexes started out as medium quality and much used drills get replaced with cobalt.

For drilling out bolts/studs with a drill motor it is hard to beat L handed bits often they'll just back right out when you near the bottom.

Steve
Click to expand...


I have about left hand bits a few times for broken bolts. I will see about getting some LH drills for bolts.
 
Ok, I think I will save the money and get some larger taper drills with the money I save. If I need cobalt for some reason, I could just get the ones I need, so that way I don't have 115 cobalt and only use 10 of them.

Thanks for all yall help.
 
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