### Where to buy "Counterbore" tool. ###

[5150bronco]

Okay Offroader. I used caliper and the 3mm cap measured 5.34mm.

So, I think the guy gave me the wrong part number, but now thanks to you I know exactly what I am looking for in terms of hole size.

Thanks.

[5150bronco]

Originally Posted by DarkSoul

A "counterbore" tool is just an endmill. They are not something that can just be thrown in a drill press and used. The part needs to be securely fastened down in a vice or clamped, and them the tool running at a pretty decent speed, usually over 1200rpm for aluminum and fed into the part very slowly.

If you are not careful, it will grab the part and royally damage it.

So for alum you want to put part in vise and than drill in it?
I am more focusing on delrin now. I see and thanks for letting me know with alum this process is a little more delicate i guess.

Thanks for the part number and helping me find this hard tool....lol.

Originally Posted by Mayhem Eng.

Step drills work great.

Can you explain what a step drill is and the use. Thanks.

Originally Posted by 62PYRO

Sorry.Wasn't trying to flame you.Those tools aren't my preferred method either but,not everyone has access to a mill.And yes,you're correct,it would be a good idea to clamp the part down.It doesn't feel good if it spins.

I dont have mill, I was going to use drill press and a flat vise to secure the part, preferable delrin I am experienting with and than I want to try alum.

So about 1200 rpms for alum than and should this work for delrin, what i said above.

THANKS A LOT FOR THE ADVICE. Trying to learn and do this stuff on my own.

[Joat]

Any material can bite you back, safer to clamp whatever it is down

Unibits are teh best, dont buy knock offs ,they dont spin true or cut as well as a "Unibit", get the ti ones or for steel get the cobalt ones, and they even make metric ones, but harder to find

1200 rpms and not clamped down is asking for a big hurting, more like 500 rpms, you dont want speed for delrin without coolant.
Oh and my set is from m3 to m12 ,m3 and so on will do any type of socket cap , so if you are using a m3 bolt you use a m3 counterbore.

[5150bronco]

Originally Posted by Joat

Any material can bite you back, safer to clamp whatever it is down

Unibits are teh best, dont buy knock offs ,they dont spin true or cut as well as a "Unibit", get the ti ones or for steel get the cobalt ones, and they even make metric ones, but harder to find

1200 rpms and not clamped down is asking for a big hurting, more like 500 rpms, you dont want speed for delrin without coolant.
Oh and my set is from m3 to m12 ,m3 and so on will do any type of socket cap , so if you are using a m3 bolt you use a m3 counterbore.

Where can I get unibit?

what do you mean by coolant for delrin?

So, you mean clamp down the material you are going to drill, right?

Thanks for the help!

[Joat]

Originally Posted by 5150bronco

Where can I get unibit?

what do you mean by coolant for delrin?

So, you mean clamp down the material you are going to drill, right?

Thanks for the help!

Just about anywhere, though ebay is the cheapest for me, go with the ti coated ones

http://cgi.ebay.com/Irwin-Unibit-Ste...QQcmdZViewItem

If your gonna try to cut delrin at 1200 rpms you may want to use a cutting coolant

http://littlemachineshop.com/product...=2236&category= this is just an example, not sure if this could be used on delrin, I dont see why not but have not tried ?

You would need a flood or mister
http://littlemachineshop.com/product...=2725&category

http://littlemachineshop.com/product...=3521&category=

[binaryterror]

Why not countersink?

The purpose of countersinking is to make the head flush while removing less material and allowing the screw head to actually strengthen the piece with the removed material.

[Mayhem Eng.]

Countersink aka c'sink will not give you a flat bottom, counterbore aka c'bore will give you a flat bottom. Depending on what type of screws you are using would dictate what tool to use.

A step drill is a drill that has lets say a .250 dia pilot and .375 dia drill, The .250 pilot drills through the material and the .375 creates a .375 c'bore x what every depth you want.

Kinda hard to describe, I will post up a pic of a step drill later. C'sinks come in different angles 82 deg's 90 deg's 120 deg's included angle meaning both sides add up. So a 90 deg tool will cut 45 on each side 45 + 45 = 90 included angle.

Originally Posted by binaryterror

Why not countersink?

The purpose of countersinking is to make the head flush while removing less material and allowing the screw head to actually strengthen the piece with the removed material.

[binaryterror]

I understand Mayhem...my point was to the original poster.

I'm a huge fan of C'sink over counterbores. Trying to figure out why he's stuck with CounterBoring...unless like you he has a mill.

Mayhem, something I've always wanted to ask you...why don't you use c'sink screws? They'd be flatter on the face. Only problem might be your ring design that helps with the bead. I know I've not tried countersinking my Mayhems, but every other Beadlock I've bought is countersunk with strong black oxide screws.

[Mayhem Eng.]

I understand.

As far as c'boring my rings it was just the way we headed. We ordered screws with the flat backside and that lead to the c'bore. We buy screws 15000 at a time and get a good price on them I would hate to change and the price of screws goes up......I will take a better look and see if there is any benefit to switching. The black oxide screws cost more and we will provide them if the customer wants them they just need to ask.

Originally Posted by binaryterror

I understand Mayhem...my point was to the original poster.

I'm a huge fan of C'sink over counterbores. Trying to figure out why he's stuck with CounterBoring...unless like you he has a mill.

Mayhem, something I've always wanted to ask you...why don't you use c'sink screws? They'd be flatter on the face. Only problem might be your ring design that helps with the bead. I know I've not tried countersinking my Mayhems, but every other Beadlock I've bought is countersunk with strong black oxide screws.

[binaryterror]

Ok makes good sense, I was just checking to see if you've noticed a problem in c'sinks or their screws. I know it does get iffy with the angles...I bought the wrong c'sink bit once...LOL

[5150bronco]

Originally Posted by Mayhem Eng.

Countersink aka c'sink will not give you a flat bottom, counterbore aka c'bore will give you a flat bottom. Depending on what type of screws you are using would dictate what tool to use.

A step drill is a drill that has lets say a .250 dia pilot and .375 dia drill, The .250 pilot drills through the material and the .375 creates a .375 c'bore x what every depth you want.

Kinda hard to describe, I will post up a pic of a step drill later. C'sinks come in different angles 82 deg's 90 deg's 120 deg's included angle meaning both sides add up. So a 90 deg tool will cut 45 on each side 45 + 45 = 90 included angle.

Thanks May! That is why I want c'bore and not c'sink.......

It is just really hard to find this tool. Only place I found is rutlandtool with part #11673500.

Please post pic. As of now I just bought a drill press to do this. Any suggestions welcomed.

Originally Posted by Joat

Just about anywhere, though ebay is the cheapest for me, go with the ti coated ones

http://cgi.ebay.com/Irwin-Unibit-Ste...QQcmdZViewItem

If your gonna try to cut delrin at 1200 rpms you may want to use a cutting coolant

http://littlemachineshop.com/product...=2236&category= this is just an example, not sure if this could be used on delrin, I dont see why not but have not tried ?

You would need a flood or mister
http://littlemachineshop.com/product...=2725&category

http://littlemachineshop.com/product...=3521&category=

Thanks for the websites. Perfect.

[Mayhem Eng.]

Step Drill



c'bore I use this tool for my vise jaws.

[Joat]

Kinda pricey for me

http://cgi.ebay.com/3-0-MM-Cap-Screw...QQcmdZViewItem

[5150bronco]

Originally Posted by Mayhem Eng.

Step Drill
Attachment 89081


c'bore I use this tool for my vise jaws.
Attachment 89082

Thank you mayhem! Where can I get one of those?????

I think that tool "step drill" may be better for plastic than "C'bore"

Thanks joat for the ebay url!

Cant wait to get this going.......



FYI.......the counterbore tool part #11673500 I listed below is only good for metal....NOT PLASTIC OR DELRIN according to rutlandtool expert........

[Joat]

Originally Posted by 5150bronco

Thank you mayhem! Where can I get one of those?????

I think that tool "step drill" may be better for plastic than "C'bore"

Thanks joat for the ebay url!

Cant wait to get this going.......



FYI.......the counterbore tool part #11673500 I listed below is only good for metal....NOT PLASTIC OR DELRIN according to rutlandtool expert........

I always use metal cutting tools on delrin , I never had problem using mt cbores on delrin? cuts clean and smooth, I know plexi requires a special drill bit and saw blade if cutting on table saw dont think delrin is nearly as finiky?

[C*H*U*D]

Originally Posted by binaryterror

Why not countersink?

The purpose of countersinking is to make the head flush while removing less material and allowing the screw head to actually strengthen the piece with the removed material.

I know the original point of this post was to locate the tool needed, and I don't want to keep going in different directions, but there is more to countersinking vs. counterboring than just sitting flush to the surface.

One is overconstraining when using countersinks. This is especially true as more and more parts are bolted together in an assembly. A counterbore has more side to side movement. As you tighten a countersink, the angles meeting together is what locates the part.....even with clearance on the shaft, the head determines the location. As tolerance stackups add up, this can be a problem.

Another is the hoop stress that is generated when using countersinks. Torquing can split the material that the countersink is exerting force into......you've probably seen this if you've ever overtightened a countersink into a plastic part. Counterbore load is axial.....force is only applied straight down on the flat surface.

Don't get me wrong......I like both and they each have their place. It's just that aesthetics shouldn't be the only consideration.

[5150bronco]

Thanks CHUD. That is right. I want to concentrate the force applied and I want a flat surface to for the bolt.

Still trying to find the tool, but will post pics soon, when I figure out how to resize the pics.

This is mainly for the skid plate and mounting the tranny up. This is what I am trying to do now and I want to do it right.

[5150bronco]

So, I just ordered and found a step drill for 3mm cap screw at Michigan drill part #371M for 13.95 shipped.

We will see.

[Joat]

Originally Posted by 5150bronco

So, I just ordered and found a step drill for 3mm cap screw at Michigan drill part #371M for 13.95 shipped.

We will see.

Glad your getting somewhere

[5150bronco]

Originally Posted by Joat

Glad your getting somewhere

Yea, I just hope it is the right one. Will let you know. lol.