5C Collets For Tap Shanks

[JoeLee]

Those tap shanks are all drill sized. You could have made a set of sleeves for them and have the job done by now! Bore the holes if you want to, or drill close and "ream" with a drill having the corners rounded and backed off a bit.

How do you figure the tap shanks are drill size?? They are close.
1/4" shank size is .2535 closest letter E or F drill
5/16' is .316 closest being letter O drill
3/8" is ..380 closest being letter V drill 3/8" drill being .375

Sure, the sleeve will expand a little but for that perfect fit it will have to be bored unless I order special size reamers. This is where the ERs come in handy.

The shank sizes may differ from one mfg. to the other. These measurements are taken from the ones that I need to point. The bushings would have to be thin walled as 5C collets don't have the squeeze power that a chuck has, but that's not an issue since I'll be lightly grinding the bevels.

JL.................

[thin-woodsman]

You can get a 5C to ER adapter and use ER collets. ER stands for Extended (grip) Range. ER collets can collapse as much as .030 in many cases.

That's a very good thing to know about. I have a 5C collet closer in my 14" lathe, and one of the problems I have is constantly having to put a chuck in to grip some stock that is more than 0.01" off nominal. I have a bunch of ER32 colletes for the mill just sitting there gathering dust - I found them more fiddly for tool changes than R8, and being on the tall side, working with the drawbar is easier for me than working with the spindle. An ER-32 for the lathe would give me a decent option for roughing the stock down to 5C size.

EDIT: Reortedly, a 31/32" 5C collet willl hold an R8 collet. Will have to set up my R8 ER32 chuck and see what the runout looks like. Might be a bit scary.

[JoeLee]

That's a very good thing to know about. I have a 5C collet closer in my 14" lathe, and one of the problems I have is constantly having to put a chuck in to grip some stock that is more than 0.01" off nominal. I have a bunch of ER32 colletes for the mill just sitting there gathering dust - I found them more fiddly for tool changes than R8, and being on the tall side, working with the drawbar is easier for me than working with the spindle. An ER-32 for the lathe would give me a decent option for roughing the stock down to 5C size.

EDIT: Reortedly, a 31/32" 5C collet willl hold an R8 collet. Will have to set up my R8 ER32 chuck and see what the runout looks like. Might be a bit scary.

How do you hold an R8 in a 5C collet?? What is going to close the R8 ?

A 31/32" R8 is not going to close up enough to grip the area between the taper and the end. Some R8's are rough turned between the taper and the end, others such as my Lyndex are ground slightly below the .950 end. My Lindex measure .945 between the taper and the end. And yet compressing the R8 in the center behind the taper wouldn't give sufficient clamping force to hold anything

Reportedly says it all.


JL............

[Toolguy]

I made a 5C to R8 adapter that has a 3/4" 7/16-20 socket head cap screw in the back to draw the R8 collet into the taper just like on a mill spindle. You put your part in the R8 and tighten it up, then put the whole works in the 5C chuck, spindle, collet block, or whatever. I agree that clamping on the middle of the R8 will not prove to work well.

[JoeLee]

I made a 5C to R8 adapter that has a 3/4" 7/16-20 socket head cap screw in the back to draw the R8 collet into the taper just like on a mill spindle. You put your part in the R8 and tighten it up, then put the whole works in the 5C chuck, spindle, collet block, or whatever. I agree that clamping on the middle of the R8 will not prove to work well.

That's the way to do it. Just like a 5C collet hex or square block.

But I have to question...... if you have 5C's why would you want to use an R8 in a holder ?

JL......................

[BCRider]

How do you figure the tap shanks are drill size?? They are close.
1/4" shank size is .2535 closest letter E or F drill
5/16' is .316 closest being letter O drill
3/8" is ..380 closest being letter V drill 3/8" drill being .375

Sure, the sleeve will expand a little but for that perfect fit it will have to be bored unless I order special size reamers. This is where the ERs come in handy.

The shank sizes may differ from one mfg. to the other. These measurements are taken from the ones that I need to point. The bushings would have to be thin walled as 5C collets don't have the squeeze power that a chuck has, but that's not an issue since I'll be lightly grinding the bevels.

JL.................

To be fair if you drilled 1/4" and with most drills tending to drill slightly over their nominal size chances are good that a split bush drilled to 1/4 would slide over the tap shank with a nice satisfying squeeze. But the odds of the drill wandering a hair are also good so it may not be totally centered. And that's where we come back to drilling 15/64 or a letter size that is a little under and skim out to size which also trues up any centering errors.

I was assuming that you already knew about ER collets due to all the mentions that they get here on the forum. But since that isn't the case I think you'll enjoy one of the ER chucks with the 5C shank to fit your present 5C tooling.

As for the taps what is wrong with the cone that is already on them? What you see is what the factory put there for centering up the tap for some of the operations during manufacturing. It just means you need a little bigger cup for the tapping guide. And if you did make the cones that are there already by the time they were sharp enough to fit a small center cone there won't be much or perhaps no square left. I'm thinking that what you need is either a bigger cup on your spring loaded guide or a new bigger guide suitable for the sizes that don't have the little center hole.

[thin-woodsman]

How do you hold an R8 in a 5C collet?? What is going to close the R8 ?

Well, the ER32 has an R8 shank, so there is no R8 collet involved.

I had come across the use of a 31/32 5C for machining a blank R8 collet. It might work to hold the ER32 chuck, it might not.

[BCRider]

I don't see much point in a 5C to R8 adapter unless we only have R8 collets. The 5C collets are not expensive and they come in a wider range of sizes and shapes by far than R8's. And they hold in the same manner with a short and focused grip area right at the nose.

And an R8 held in a 5C? "Reportedly" does not do justice to how sketchy that idea is. I can't imagine holding an R8 in a 5C collet and pressing in on the smaller diameter mid area is going to come to any good at all. Especially since many (all in my case) R8 collets and shanks on solid shank R8's are relieved in the middle to thin the walls for more flexibility and not ground in that area. It simply won't work in most cases at all. You'd never get the fat end to fit through the size of collet needed to fit the relieved middle portion.

[jimsehr]

Shars has 5c emergency collets for $7.50 . Buy a few and bore them to size. I don’t think you could hardly by the material to make bushings that cheap.

[J Tiers]

How do you figure the tap shanks are drill size?? They are close.
........

Sure, the sleeve will expand a little but for that perfect fit it will have to be bored unless I order special size reamers. This is where the ERs come in handy.

The shank sizes may differ from one mfg. to the other. These measurements are taken from the ones that I need to point. The bushings would have to be thin walled as 5C collets don't have the squeeze power that a chuck has, but that's not an issue since I'll be lightly grinding the bevels.

JL.................

I have a ton of taps from a wide range of manufacturers. I also have an old crappy Cedarberg tapping "machine" (frame that holds a tap driver at 90 deg to surface) that I got for a buck with no holders.

So I went through the taps, and found that essentially every one fell into one of six sizes. I made a holder for each size, and I have yet to find a tap that does not fit them. Each size was a drill size within close limits. I drilled and reamed with a modified drill for the sizes that I had no reamer (trick from an ancient toolmakers handbook).

You can do what you like, or put me on ignore. My rule in the shop for tools that I find I need, is generally that I only buy what I cannot make (or can get for less money than if I made it). It's not 100% followed, but usually so. (exception for things I find at tag sales that I can see wanting). I'm generally not a production house, so anything I make is good shop time.

[JoeLee]

I have a ton of taps from a wide range of manufacturers. I also have an old crappy Cedarberg tapping "machine" (frame that holds a tap driver at 90 deg to surface) that I got for a buck with no holders.

So I went through the taps, and found that essentially every one fell into one of six sizes. I made a holder for each size, and I have yet to find a tap that does not fit them. Each size was a drill size within close limits. I drilled and reamed with a modified drill for the sizes that I had no reamer (trick from an ancient toolmakers handbook).

You can do what you like, or put me on ignore. My rule in the shop for tools that I find I need, is generally that I only buy what I cannot make (or can get for less money than if I made it). It's not 100% followed, but usually so. (exception for things I find at tag sales that I can see wanting). I'm generally not a production house, so anything I make is good shop time.

That's about what I found also.
I started making a few collets for the taps. So far after drilling the tap doesn't fit the hole but after I slit it I'm sure it'll spring enough for a good fit.
I can get better concentricity than the .0004 that these ER's have.

JL..........

[JoeLee]

To be fair if you drilled 1/4" and with most drills tending to drill slightly over their nominal size chances are good that a split bush drilled to 1/4 would slide over the tap shank with a nice satisfying squeeze. But the odds of the drill wandering a hair are also good so it may not be totally centered. And that's where we come back to drilling 15/64 or a letter size that is a little under and skim out to size which also trues up any centering errors.

I was assuming that you already knew about ER collets due to all the mentions that they get here on the forum. But since that isn't the case I think you'll enjoy one of the ER chucks with the 5C shank to fit your present 5C tooling.

As for the taps what is wrong with the cone that is already on them? What you see is what the factory put there for centering up the tap for some of the operations during manufacturing. It just means you need a little bigger cup for the tapping guide. And if you did make the cones that are there already by the time they were sharp enough to fit a small center cone there won't be much or perhaps no square left. I'm thinking that what you need is either a bigger cup on your spring loaded guide or a new bigger guide suitable for the sizes that don't have the little center hole.

I knew they existed but like most things you never really pay attention to the details until you need one.

I've seen them advertised for years. There are quite a few brands out there. Who is good and who isn't?? ETM or TMX (Tool Mex) comes to mind.
Lots of other brands out there that I've never heard of. Are they all about the same ?? .0004 concentricity........ about as bad as a cheap 5C.

Cheaper to buy like an 11 pc set than individually.

JL.................

[Ian B]

Here's a table of ER collet sizes: https://community.carbide3d.com/t/er...ts-sizes/20664

Ian

[JoeLee]

That's a good chart to have ...... TNX......

JL.............

[JoeLee]

I got mine from ArcEurotrade. They are on eBay and Amazon, too. https://www.ebay.com/itm/Precision-C...EAAOSwk-Jd6b4-

Did you ever check the run out on this holder??
As I was looking at various brands of ER32's I see the TMX ToolMex / Bison ones say .0004 concentricity. Some say .0001. I always thought TMX was pretty good quality.
Are some brands more accurate than others?? There are quite a few out there, most I never heard of.

JL............