Thread: Morse taper drill recommendations

Yeah i guess it depends on the hand drill. My cordless Protool will happily go 10mm pilot then 1" through cast iron or ally without breaking sweat. I recently holesaw'd a 44mm hole through 3/4" of cast iron with it, that was hard work...

Im glad i was persuaded to go reduced shank over MT, as i can use them in any of my tools (big mill, little mill, hand drill, lathe, drill press -and i dont have to muck around freeing the MT chuck from the drill press every time)
I have a 32mm 1/2" shank drill which i thought might be pushing things, but it goes ok. I use a 10mm pilot then straight out to 32 in alloy, in a 16mm chuck in the tailstock. Maybe add a ~22mm step if drilling steel.

FWIW i was told not to open up the hole sizes in small steps, the pilot should be 1/3-1/2 dia of the next drill. Once switching to this method i found i needed to sharpen the drills a lot less as the tips werent getting knocked off anymore.
Even in smaller lathes try bigger steps, just drop the speed and/or feed to reduce chatter.

Needed a 1" drill and a couple of other sizes so held my breath and ordered the Ozmestore set for $50. They arrived promptly, post free and were put aside
till needed. In light of others reports thought I had better check them out so chucked each one in the 3MT drill press and looked for obvious runout. All seemed OK. Had a piece of square trailer axle to hand so put the 9/16" drill into it firmly at 500rpm with a few drops of oil and it seemed to cut well and evenly. Mounted the 1" drill and set it over the 9/16" hole and fed it firmly at 250rpm. Again seemed to cut well , so added some oil and pushed it beyond the bottom of the 9/16" hole, (no pilot hole) and it still made fair progress. Wiped both drills clean and looked at flutes and cutting edges, found no sign of dull edges or chips. Realise this was a quick and crude test but for my purposes they will serve to make holes in mild steel and rough out bores in the lathe.
Maybe they really are some grade of HSS as advertised? time will tell. Combustor.

Originally Posted by Ueee

Hi Rob,
How are taper shank drills restrictive?

Ew

You can't use them in standard chucks on other equipment.

Rob

Originally Posted by nearnexus

I can't see the point of buying morse taper drills.

I use an E32 collet in the tailstock.

That way you can use the drills in other equipment.

I used to use a Metabo key chuck on a morse arbor, but the ER is way better accuracy wise and also it does not allow the drills to slip.

Just another option to think about.

Rob

Dito mate , have an ER 32 and 40 collet chuck with MT3 . If I think the drilling job is too hard for the Jacobs chuck or the drill don't fit , then I have the collet chuck option . Generally what gets people into trouble is heat build up and hardening of the steel as they drill . A lot of hobbyists , me included use a lot of scrap unknown steels and some harden up as quick as lightning right at the cutting surface as the drill goes along . Not good .

Originally Posted by nearnexus

You can't use them in standard chucks on other equipment.

Rob

Well, duh, that's kind of the point..... they're meant for the bigger jobs. I admit that I rarely bother with TS drills less than 12mm dia because there's no real point for what I do.

TS drills *usually* are longer than straight shank ones, they go *much* bigger in diameter and - if driven properly - they do not slip.

You may claim that a straight shank drill won't slip in an ER32 collet, and you may well be right - for the force that you've applied. HOWEVER, the *only* thing stopping the *collet chuck* taper from spinning in a tailstock is the friction fit because it has no tang and you can't use a draw bar. So basically you've just moved the possible point of movement to, IMO, a worse one in terms of damage, than spinning a drill in a chuck. Now if you've mounted a collet chuck to a tanged shank, *and* your TS has a tang recess, then maybe you can transfer a significant amount of force. But somehow I doubt this applies. If you did this, then you could no longer use it as a milling chuck (with any degree of safety) as you wouldn't have the ability to use a drawbar.

I would like to see you put a 40mm reduced shank bit held in an ER32 collet held by a 3MT shank (or worse, a 2MT) into a 12mm dia pilot hole through 125mm of A36 plate.

Frankly I think you don't have a use for TS drills because your equipment lacks the power, rigidity & design to use them to their proper capacity. That may make them useless for you, but that's a lot different from there being no point in them existing.

FWIW I have quite a lot of drill chucks from 6mm capacity to 20mm capacity, mix of keyless ones and Jacobs keyed chucks. Pick the best tool for the job at hand.....

PDW

Now if you've mounted a collet chuck to a tanged shank, *and* your TS has a tang recess, .............. If you did this, then you could no longer use it as a milling chuck (with any degree of safety) as you wouldn't have the ability to use a drawbar.

Alternatively you fit it to a threaded shank so it can be used in the mill and make a screw-in tang for use in the lathe tail-stock.

[QUOTE=PDW;1739738]Well, duh, that's kind of the point..... they're meant for the bigger jobs

I would like to see you put a 40mm reduced shank bit held in an ER32 collet held by a 3MT shank (or worse, a 2MT) into a 12mm dia pilot hole through 125mm of A36 plate.

Frankly I think you don't have a use for TS drills because your equipment lacks the power, rigidity & design to use them to their proper capacity. That may make them useless for you, but that's a lot different from there being no point in them existing.

[end quote]


The discussion by the OP was for morse drills up to 25 mm.

The alternative in that size range is reduced shank drills. It's another option, as I said. The benefit is that you can use them in other equipment.

Show me where I said there is no point for taper drills existing ?

Rob

Greetings,

So, first up I have a pretty good range of Cobalt MT1 imperial drills that I bought for my little Sherline Mill. There is a reasonable range of MT drills available if you don't need it right now and can sit on ebay or the like for awhile. My drills came from the US, 5 of each size in a package. I simply sold off two of each size on ebay to get my costs back down.

Drills have a manufacturing tolerance, possible something like "H5" stamped on them or the container they come in. This is one of those things you pay for. Drill chucks and ER chucks also have runout. As has the arbors they mount on. Thus the more interfaces the more runout. Drills are often for roughing out holes, as has been pointed out, so a bit of runout generally isn't that much of an issue. They don't have to be just roughing, a lot depends on your techniques and the drills etc. Runout also shortens the life of the cutting edges as it does with all tools. To get your runout down on straight shank drills you will need to buy a high quality drill chuck. The prices on, say, an Albrecht chuck will make almost any set of Taper shank drills look cheap! And of course your nice expensive drill chuck runs in the same taper as the taper shank drill would have.

Another often overlooked aspect of this argument is how much axis you have available on your machine compared to your job requirements. By this I mean that a drill chuck and straight shank drill have a certian length which is likely to be more than say a taper shank drill inserted direct into the machines taper. That distance maybe just more than will allow you to fit your job under the drill's point. You don't need to play with miniature machines to discover that! Sure you can use shorter straight shank drills.

You can move taper shank drills readily between machines. I have adapters for 40 taper and 5c collet.

I'm not arguing for one drill style or the other, there is a place for both, should your budget allow.

Cheers

The Beryl Bloke

Originally Posted by PDW

Well, duh, that's kind of the point..... they're meant for the bigger jobs. I admit that I rarely bother with TS drills less than 12mm dia because there's no real point for what I do.

TS drills *usually* are longer than straight shank ones, they go *much* bigger in diameter and - if driven properly - they do not slip.

You may claim that a straight shank drill won't slip in an ER32 collet, and you may well be right - for the force that you've applied. HOWEVER, the *only* thing stopping the *collet chuck* taper from spinning in a tailstock is the friction fit because it has no tang and you can't use a draw bar. So basically you've just moved the possible point of movement to, IMO, a worse one in terms of damage, than spinning a drill in a chuck. Now if you've mounted a collet chuck to a tanged shank, *and* your TS has a tang recess, then maybe you can transfer a significant amount of force. But somehow I doubt this applies. If you did this, then you could no longer use it as a milling chuck (with any degree of safety) as you wouldn't have the ability to use a drawbar.

I would like to see you put a 40mm reduced shank bit held in an ER32 collet held by a 3MT shank (or worse, a 2MT) into a 12mm dia pilot hole through 125mm of A36 plate.

Frankly I think you don't have a use for TS drills because your equipment lacks the power, rigidity & design to use them to their proper capacity. That may make them useless for you, but that's a lot different from there being no point in them existing.

FWIW I have quite a lot of drill chucks from 6mm capacity to 20mm capacity, mix of keyless ones and Jacobs keyed chucks. Pick the best tool for the job at hand.....

PDW

That is correct about the collet chuck but an ER40 collet will hold better than many TS chucks will at the collet jaws . If they have the same tab at the end they hold the same as a MT drill will in the MT socket because they have the same tab . With a MT drills grip you are only considering the socket. With a drill chuck with MT arbour you have to consider three areas of grip. The jaws , the Jacobs taper and the Morse taper . In my experiece the most likely area of slip is the short Jacobs taper . I have a Jacobs super chuck and on hard drilling jobs it wil give up at the jacobs taper first , no matter how I degrease it or how hard I hammer it together . It's just the point of least grip . A Collet chuck with a normal MT locking tab does not have that third weak spot . There is nothing wrong or incorrect about using MT drills if that is what you want or need. However hobbyists with limited funds should not plunge into buying just MT drills only because at some point you will need a tail stock chuck anyway and most hole drilling will be small stuff and you need something to hold center drills anyway . Buy the MT drills as you need them for a specific job not drop a small fortune on a whole set.

Originally Posted by Retromilling

That is correct about the collet chuck but an ER40 collet will hold better than many TS chucks will at the collet jaws . If they have the same tab at the end they hold the same as a MT drill will in the MT socket because they have the same tab . With a MT drills grip you are only considering the socket. With a drill chuck with MT arbour you have to consider three areas of grip. The jaws , the Jacobs taper and the Morse taper . In my experiece the most likely area of slip is the short Jacobs taper . I have a Jacobs super chuck and on hard drilling jobs it wil give up at the jacobs taper first , no matter how I degrease it or how hard I hammer it together . It's just the point of least grip . A Collet chuck with a normal MT locking tab does not have that third weak spot .

I don't think anyone is disputing the weaknesses of using a drill chuck with an MT arbor.
I thought the discussion is between
a) TS drill in an tanged or untanged MT sockets
and
b) RS drill in a collet holder in a tanged or untanged MT Socket

The way I understand it is, in terms of strength, a) should be stronger than b) because b) includes a), and because a RS bit is simply not as strong as a TS bit.
From an accuracy point of view, a) uses one component, so if all things are equal a) should be more accurate than b)
In practice since TS drills are longer than RS bits and because collets are likely to introduce very runout then b) may indeed be more accurate than a)
Not that accuracy really matters for drilling since it is usually used for approximate work.

The post precise drill would be using a stubby drill TS bit. I have noticed quite a few of these in the bit collection of the workshop where I used to work.

Interested to hear that a Jacobs taper will let go. May depend how it's fitted. Recently put one, 3MT, into a mount for a 80mm rock coring drill. Put the taper arbor in the freezer overnight and poured a jug of boiling water over the female arbor. Just bumped it in firmly and the guy is coring rock with it on a No 5MT radial drill. Will let you know if it ever slips, Combustor.

I was opening up a hole yesterday with a 9/16" drill in the lathe. 5/8 keyless chuck with a B18 MT4 arbor. I had a bite and pulled the chuck off the arbor. The chuck is also now so tight i can't get the drill out. Need to take to it with a strap wrench. I just hope the chuck is ok from being overtightened. Give me a MT drill any day.....

Ew

You've given me plenty to think about. Appreciate all the discussion.

Thanks,
Joe

If you're interested I may have a set of P&N taper shank drills to sell, 9/16-1" by 16ths. And I believe the 7/8 is missing.