I don't yet have the studs. I know they have a bit of a ridged shoulder where they press in. What size hole is that shoulder designed for?

Don't answer this... Because you don't know the answer.

Seriously, it is 'VERY' stud dependent. We have literally 4 different sizes that we drill hubs and rotors with... 5 now thanks to Peter Newman

Verbus is the most consistent.

Too tight and the splines on the stud will peel and leave an uneven mounting surface.

Too loose and, of course the stud will fall right through and then have to be welded into place... heaven forbid you want to add spacers and longer studs later.

So the answer is "I don't know." Take the studs and the hubs to a qualified machinest and have them drilled specifically for the stud you're going to use.

QUOTE (Eric_Shea @ Mar 8 2006, 05:54 PM)

Don't answer this... Because you don't know the answer. Seriously, it is 'VERY' stud dependent. We have literally 4 different sizes that we drill hubs and rotors with... 5 now thanks to Peter Newman Verbus is the most consistent. Too tight and the splines on the stud will peel and leave an uneven mounting surface. Too loose and, of course the stud will fall right through and then have to be welded into place... heaven forbid you want to add spacers and longer studs later. So the answer is "I don't know." Take the studs and the hubs to a qualified machinest and have them drilled specifically for the stud you're going to use.

Argh.. so if you buy a 911 hub they don't come pre-drilled? There has to be a size it is "supposed" to be.

I am the "qualified machinist" that will be drilling the hubs.. I'm trying to figure out what drill bit to buy.

Is it a 911 hub? It should have studs in it...

If it's a 914 hub you want to drill then you'll need to decide which stud to use.

If you want to go the 911/Porsche route, meause any Verbus stud, then make sure you use Verbus studs. They're $70 or more for a set of 10. Some can be over $10 and almost $20 each!

If not and you want to use another stud then hold off on your bit decision until you get the studs. 14x45mm is what is on a stock early 911 hub.

I believe the machinest uses a vertical mill as well...

QUOTE (Eric_Shea @ Mar 8 2006, 06:08 PM)

I believe the machinest uses a vertical mill as well...

I'll be using a bridgeport and a rotary table. I need to buy a 14mm drill bit to drill out some spacers, I'm just trying to figure out if it can do double duty for 914 hubs. If there's any chance it will, I might buy something better than the bottom of the line 14mm bit.

It's a 14mm stud, I think 14 might be too big

I'm not the machinest though... all I know id studs sizes vary wildly. Verbus is consistent.

they should be reamed to size...not drilled, small chamfer on both sides....did a set for Fiid a few months back... 14mm diameter for his hubs I believe....

QUOTE

It's a 14mm stud, I think 14 might be too big

how are you going to get a 14mm stud thru a "smaller" hole??

QUOTE (bondo @ Mar 8 2006, 08:51 PM)

QUOTE (Eric_Shea @ Mar 8 2006, 06:08 PM) I believe the machinest uses a vertical mill as well... I'll be using a bridgeport and a rotary table. I need to buy a 14mm drill bit to drill out some spacers, I'm just trying to figure out if it can do double duty for 914 hubs. If there's any chance it will, I might buy something better than the bottom of the line 14mm bit.

Old school. I did a set for my car (before I got the 914/6 rear hubs). I set them up in the mill and programmed the CNC to do the proper drill pattern. I still have the disk if anyone has access to a CNC machine that uses G code.

Digging up an old thread...

I got me some Verbus studs. Sounds like I should get a 14mm ream. How much under 14mm should I drill, before reaming to the final size? I'm doing this to a set of early hubs, so I don't want to screw them up.

We undersize by .002" I believe.

I would think a suitable hole diameter is .XXX amount less than the major diameter of the splines, rather than .XXX amount more than the threaded portion of the stud or based on the thread size.

Eric, since you've done a number of these, is there a "less than" number that you use? This way you'd only need to measure the spline and subtract .XXX. Afterall, it's simply a matter of metal displacement.

Andys

On a related note... Has anyone used this ream set? The price seems too good to be true.

Harbor Freight Ream Set

Uuuuuuuuuuuuuuuuuuh... read above?

Found the answer to my own question. Drill size should be .010" to .015" smaller than ream size. Apparently taking off to little with a ream dulls them. Who knew?

Don't buy a cheap reamer set. Go to MSC (www.mscdirect.com) and first get yourself a catalog, then order up a decimal size reamer. You can get anything you want and they aren't that expensive. Buy decent ones for the sizes you need and you'll have tools you want to use, not cheap ones that don't cut well and make wrong size holes.

And - drilling and reaming is not necessary. If your working with good drills, they can drill holes within .0005. That's more than close enough.