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Allied Spade Drill

Been using spades for at least 40 years in all kinds of material. 1.5 up to 3.25 dia. as much as 24 inches deep. Hardly ever drill a pilot hole. In manual lathes only, as I've never had a CNC lathe with enough balls to push a spade. Inserted drills work well in the cnc's.
 
I drill 4140 CDHT often but very little stainless, when I use my 1/2" x 9" deep AMEC (cobalt, tiny chip insert) I start with a stub drill for starting no center drill, and switch to the long drill to finish. High pressure coolant (mineral oil) never had any trouble.

But then the OP hasn't given hole tolerance either, if he's looking for +/- .001" straight and +/- .0005 bore diameter with no bell mouth at entrance that could (very likely) become a problem depending on many factors including his machine rigidity especially at 10" deep.
No tolerance on hole. Its simply for weight reduction there will be a plug welded into it. But it has to be 1.25" for the part to hit the required weight!
 
Been using spades for at least 40 years in all kinds of material. 1.5 up to 3.25 dia. as much as 24 inches deep. Hardly ever drill a pilot hole. In manual lathes only, as I've never had a CNC lathe with enough balls to push a spade. Inserted drills work well in the cnc's.
My old shop we had Doosan Machines and I used to use 2-9/16" drills into 4140 all the time. This is only my second time using a spade drill at this shop for holes. I ended up using my own money to buy a second shorter drill same company through coolant for the pilot. The company will buy it back from me. Thankfully this current order is only 10 pieces but next time they want 200 every year. Not an issue once Ive proven the process out.
 
No tolerance on hole. Its simply for weight reduction there will be a plug welded into it. But it has to be 1.25" for the part to hit the required weight!
Don't sweat it then, drill won't wander that much anyway. Play with your speeds and feeds to find the sweet spots and run with it.
 
Allied spade drills are awesome! Maybe not the fastest way to drill every hole, but certainly a reliable and cost-effective method of hole popping.

As said, spade drills do require a TON of thrust, and often your machine will not have the Z-axis power to run at the recommended feed per tooth. So I just find a FPT that the machine likes, although that can make for stringy chips.

Allied has some new spade drill insert geometries that promise to be way-better at chip breaking, so you may want to give them a call if you have issues.

ToolCat
 
Allied spade drills are awesome! Maybe not the fastest way to drill every hole, but certainly a reliable and cost-effective method of hole popping.

As said, spade drills do require a TON of thrust, and often your machine will not have the Z-axis power to run at the recommended feed per tooth. So I just find a FPT that the machine likes, although that can make for stringy chips.

Allied has some new spade drill insert geometries that promise to be way-better at chip breaking, so you may want to give them a call if you have issues.

ToolCat
Yeah. I just got to use the drill and only 1" into my drilling I get a SV0436 Soft Thermal Z error. So im guessing the machine cant handle the the thrust and I might need to find a slower feed.
I was shooting for 245RPM @.011IPR Might have to rethink that.
 
In manual lathes only, as I've never had a CNC lathe with enough balls to push a spade.
We gotta get you a cinturn. 12" chucker, 26,000 lbs, front bearings good for 16,000 lbs thrust, z with 10,000 lbs thrust.

Should be able to push a spade :)

Had no problems with 2 1/2" spades in 316 in an american tool panther, but that was a mere 25,000 lbs. Kind of a lightweight, considering the 15" chuck.

For raw metal removal, these modern chipmunk-type lathes seem kinda weak.
 
We gotta get you a cinturn. 12" chucker, 26,000 lbs, front bearings good for 16,000 lbs thrust, z with 10,000 lbs thrust.

Should be able to push a spade :)

Had no problems with 2 1/2" spades in 316 in an american tool panther, but that was a mere 25,000 lbs. Kind of a lightweight, considering the 15" chuck.

For raw metal removal, these modern chipmunk-type lathes seem kinda weak.

Two things:

1. Spade drills have such a narrow application window that they can effectively be considered obsolete. Ejector drills are far more effective for deep holes, and insert drills are far more effective for big holes. Spade drills are still around because they are a kind of easy to use, widely available compromise option for the gray area in between deep and big. That and people keep buying them, I suppose. Far better options exist for the specific hole that OP is trying to drill, but a spade drill is what he has.

2. You have got to get over this "modern lathes are crap" notion that you are stuck on. Heavy duty lathes are still made that will comfortably outperform anything made in the 80's in terms of metal removal.

As previously, I will concede that modern lathes tend to have less Z thrust, but that's because there are vanishingly few reasons to need massive Z thrust, and MTB's can make their machines much faster with the same power envelope instead, which is more desirable to most users. The big clue is that this argument really only ever rears it's head when someone starts talking about spade drills...

Spade drills are a good option for manual machines - I like to use them in my HBM, because it doesn't have the spindle speed or sufficient feedrate control for carbide. In my CNCs though, I use spade drills basically never.
 
2. You have got to get over this "modern lathes are crap" notion that you are stuck on. Heavy duty lathes are still made that will comfortably outperform anything made in the 80's in terms of metal removal.
Yeah right. I'm calling horseshit on this. In the eighties every US builder's lathes were brutes, and nothing today outperforms them.

For job shopping, spade drills are fine. Quick, easy, versatile, inexpensive. That's why they are still around.
 
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Yeah right. I'm calling horseshit on this. In the eighties every US builder's lathes were brutes, and nothing today outperforms them.

For job shopping, spade drills are fine. Quick, easy, versatile, inexpensive. That's why they are still around.

Show me your data on this, otherwise you can call horseshit til the cows come home for all I care.

And don't start spouting massive horsepower numbers, they are meaningless, for all the reasons we've already discussed prior.

I'm a job shop, and I have insert drills in 1mm increments from 14 to 50mm and then in odd increments up to 100mm. I will run circles around anyone using spade drills for holes up to 5xD. I use replaceable tip drills wherever possible up to 8xD, and I use gundrills or solid carbide drills for smaller holes beyond 8xD.

I use spade drills for whatever is left, but it's not much and I use them rarely. I used them a lot when I was making large manifolds, but I don't do much of that anymore. Spade drills are great if you need to make like a 2" hole 40" deep or the like.
Like I said, I like them in the manuals.

Some day, maybe, I might set up an ejector drill system. I've toyed with the idea on and off for years but never really had enough suitable work to justify it.

I would note as well that spade drills are not inexpensive, and they are definitely not quick. But they are easy and versatile, I will grant you that.
 
A Sandvik DS20 7xD would poke most of that hole say, say 9" of it anyway, in less than 2 minutes.
Too bad they don't make a 8xD insert drill but maybe someone else does.

Most cnc lathes have a huge lack of Z thrust, sadly they try to go for fast rapids rather than something that's actually useful.... though low RPM torque to run a cobalt tripped spade is pretty shit as well.
 
I dont understand why people are so against spade drills here? I like them. I use Sandvik 880 and 870 drills a fair bit too, and sure they are faster no doubt. But it still amazes me how fast you can go with an allied drill using HSS insert. Hard to believe its HSS performing that well.

And the AM200 grades last a long time too. Inserts are cheap, only need a few drills on hand since each one takes a large size range. The HSS is tougher then carbide. They still have a lot of advantages. If i get a job for small run of parts 50-100pcs id much rather buy an allied insert for less then $100 vs buying an 870 drill body+insert for close to $1000
 
If i get a job for small run of parts 50-100pcs id much rather buy an allied insert for less then $100 vs buying an 870 drill body+insert for close to $1000
Yes but then you'd have that drill body for other jobs and it would pay for itself in no time.
Not to mention that 50-100 pc job would get done a lot faster and you could be running a different job in the meantime.
 
Yes but then you'd have that drill body for other jobs and it would pay for itself in no time.
Not to mention that 50-100 pc job would get done a lot faster and you could be running a different job in the meantime.
This is true. However...

Spade drills are the most forgiving indexable drilling system avaliable. Why does "forgiving" matter? Well, most cnc lathes have had their share of a bump or two, and thus the turret's effective drilling centerline is never perfect...often far from perfect.

Go stabbing a high-dollar drill system into a part where the tool and part aren't lined up pretty darn close on centerline, and you're asking for trouble.

Spade drills seem to drill just fine regardless of machine alignments. They may make an ugly hole, or sound rough doing it, but the drill lives to see another hole.

In machining there's really no limit as to the availability of "high-end, high-dollar" tools, but it's up to each user/buyer to determine the cost-versus-value tradeoff.

We can't spend the absolute most possible on every tool we buy...

ToolCat
 
Yes but then you'd have that drill body for other jobs and it would pay for itself in no time.
At a thousand bucks, no, it's not going to pay for itself in no time ... if it was that easy to make money, everybody would be doing it.

Not to mention that 50-100 pc job would get done a lot faster and you could be running a different job in the meantime.
In my experience this is not how it works. I get more throughput with slower cycle times. Running parts that take one minute, all I can do is stand there and change pieces. Running parts that take five or ten minutes, I can run two, three, even four machines and keep them all fed. So while one job is going slower, I've got three others running simultaneously. Ends up with more done at the end of the day.

Manufacturing ain't no cookie-cutter recipe book :)

mmurray70 said:
I don't understand why people are so against spade drills here? I like them.
Yeah, me too. Given the choice between an insert drill and a spade for the same job if both are sitting on the shelf I'd take the insert, sure, but if it's a small run of parts and I have to buy something, one spade body will do a bunch of different size holes, they work fine, they cost less, okay by me. Guess I'm too pragmatic for this crew :)

gregormarwick said:
Show me your data on this, otherwise you can call horseshit til the cows come home for all I care.
Without spending a year on a detailed study, let's pick a few elderly lathes and a few decent-quality new ones so as not to be accused of cherry-picking. Cincinnati, American Tool, Warner-Swasey, Jones & Lamson, Monarch, maybe Lodge & Shipley were all pretty much equivalent. Choose a size, 10" chucker. Cincinnati 10CC, 25,000 lbs, 30 or 40 hp, three gear ranges, I did find the thrust at 10,000 lbs for z.

Now go look for a modern lathe, Mazak quickturn, go to mazak site, can't even get that info, site totally sucks, information is shit, look at some used places, 6,000 lbs. Okay so that's a lightweight for little parts, let's try okuma. Okuma site also sucks, I closed their pages in disgust no I am not going to register to see how much your lathes weigh and what hp they have but a used LB3000 with similar specs to the cinturn is 15,000 lbs, about 10,000 light. 2 speeds, that's good at least but still. Not as heavily built. Look at dmg, alas, "register to download a brochure" suck my cock dmg ... SL403 looks like it might be competitive but I sure as hell am not going to open myself up to a lifetime of sales crap just to find out what it weighs and how many ponies and what kind of gearbox it has. Looked in several places, don't see that information anywhere, are they ashamed to describe the actual working parts of their machines ? Do see a lot of sales crap about how it will make my life wonderful, reserve me a cabana at club med, and give me ten free beads for before-dinner drinks but that's not much use here. Okuma Genos, similar size work envelope but again, register to find out. Fuck off, okuma. Used LB15, 1990. 9,000 lbs, about 15,000 short. Doosan Lynx, well thought of, people like them, similar envelope, 13,000 lbs. Better than okuma :) but still 10,000 lbs shy. How about a Hwacheon Hi-Tech 400, about the same envelope as my Panther was ? Not so bad, about 18,000 lbs. 7,000 shy (and 10 hp shy and I don't know how many gear ranges. Panther had 3, full 40 hp available at 50 rpm in low. And that's machine tool duty rated, actually you can run 150% overload for 15 minutes/hr without hurting anything. Gettys drives, George Foreman Edition, so when you need it you can pull 60 hp on a 40 hp machine. Panther had 2 1/2" ballscrew on z, I think ?) There's even a couple of threads here about the WSU12 https://www.practicalmachinist.com/...niversal-turning-machine-introduction.131158/ as another example ...

Spend ten minutes looking around, there's no way that newer lathes are as heavily built. Heavy = big forces. Cutting and drilling. Sorry, you are mistaken. They don't build anything but hobbers as heavy as in the past. Hobbers and shapers tho, are actually beefier :) Mass actually does matter, depending on what you are doing. Drilling holes is one of those places.
 
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At a thousand bucks, no, it's not going to pay for itself in no time ... if it was that easy to make money, everybody would be doing it.


In my experience this is not how it works. I get more throughput with slower cycle times. Running parts that take one minute, all I can do is stand there and change pieces. Running parts that take five or ten minutes, I can run two, three, even four machines and keep them all fed. So while one job is going slower, I've got three others running simultaneously. Ends up with more done at the end of the day.

Manufacturing ain't no cookie-cutter recipe book :)

I was looking at it from my perspective here at where I work.
8 lathes, 8 operators. The faster they can complete a job, the faster they can move on to the next one.
100pcs drilling.... 6" deep with a spade drill vs an indexable drill is a no brainer as to the cycle time difference I think we can all agree on that one.

1" deep... yeah cycle time difference is negligible.

In your scenario where you're running 4 machines that's a different story altogether and you're right, you could be doing more while other machines are still running.

One example here, we have a repeat job of 1,000 (4340pht?) gear blanks about 5 times yearly, they used to use a 25mm spade drill for a thru hole on a part that is about 2-1/2" oal.
I suggested a Sandvik 870 25mm drill and the total run time is night and day.
1 machine, 1 operator for that operation.
 
One example here, we have a repeat job of 1,000 (4340pht?) gear blanks
Well duh, a thousand pieces :D

(btw, want to buy a hobber ? then you could do teeth, too !)

But okay, here's another place where the spade wins : had a bunch of aluminum parts, got a 2" hole about 12" deep. With a spade drill I was already close to maxing the machine out, do they even make good inserts for aluminum drilling ? And if they did, what would it give me ? Couldn't push the machine any faster, so what do I get for a bunch more expense ?

I think you really have to take this stuff on a case by case basis.
 
Well duh, a thousand pieces :D

(btw, want to buy a hobber ? then you could do teeth, too !)

But okay, here's another place where the spade wins : had a bunch of aluminum parts, got a 2" hole about 12" deep. With a spade drill I was already close to maxing the machine out, do they even make good inserts for aluminum drilling ? And if they did, what would it give me ? Couldn't push the machine any faster, so what do I get for a bunch more expense ?

I think you really have to take this stuff on a case by case basis.

Our main customer is a gear house lol. We'll never be cutting gear teeth.

Yeah 12" deep for a 2" indexable won't be cheap.
Sandvik's DS-20 line for 2" drills only goes to about 10" cutting length.
But for 6061 they recommend 907sfpm (1730rpm) and .0061 IPR for a 10" deep hole taking 57 seconds per hole.
Not too shabby, but is the $1100 list price tag worth it?
 








 
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