metric counter bore setups?

[BigSki]

I've used aircraft style counter bores for years, the straight shaft style w/ interchangeable pilots. I need a source for the exact style of counter bore, only in metric. I've done a few hours of searching, all I can come with are one piece CB's that are made to specifically make pockets for cap head screws, this won't work for me. I need a 9mm pilot and a 11mm counter bore.

I went as far to reach out to Generis, figuring that they are a full blow fab shop in a country where metric is used, they would know where to buy. Nope, he told me that they have to have custom ground set ups made when the need arrives. Custom ground is out of my price range and abilities!

Can anyone offer a source for what I'm looking for, or 'hook a bruther up' with some custom grinding?

Thanks for any help.

[Aussie Nerd]

Will a standard slot drill work as a replacement? Drill your 9mm pilot, then drill again with the slot drill to the desired depth.

Another option may be to get a M6 counter bore (11mm diameter) and make a sleeve that press fits over the 6mm pilot that takes it up too 9mm? Something like in the link below should be able to take a sleeve alright. Not sure if that would work for you, but may be worth a shot if all else fails.

HSS M6 / 6mm Counterbore 11mm Cutter Dia Plain Shank | eBay

Best of luck
Kieren

[Etype R]

7/16 is pretty close to 11mm, it seems this style counterbore is only available in standard from what I can find.

Interchangeable-Pilot Counterbores | MSCDirect.com

At work we have bought standard sizes and had them custom ground by a local tooling place.

[SlickRockSpider]

Originally Posted by BigSki

I've used aircraft style counter bores for years, the straight shaft style w/ interchangeable pilots. I need a source for the exact style of counter bore, only in metric. I've done a few hours of searching, all I can come with are one piece CB's that are made to specifically make pockets for cap head screws, this won't work for me. I need a 9mm pilot and a 11mm counter bore.

I went as far to reach out to Generis, figuring that they are a full blow fab shop in a country where metric is used, they would know where to buy. Nope, he told me that they have to have custom ground set ups made when the need arrives. Custom ground is out of my price range and abilities!

Can anyone offer a source for what I'm looking for, or 'hook a bruther up' with some custom grinding?

Thanks for any help.

Generis can call me when the need a metric counter bores ground . How about this bruther McMaster Carr

McMaster-Carr

When I need machine tools. I first go to Mc Master Carr they rock

Edit: After looking around you are looking for more than a standard C'bore mm or not. I have all of the metric C'bores from 3 to 12. For all of the metric hard ware. No 11. If you need the pilot then you are not working on a milling machine. (?) Do you have a lathe? I have turned down shcs heads for custom stuff.

After reading SMR 510RR post he's is right. A boring head (or reamer) would keep the size of hole tight for bearings .




Evan

[SMR 510RR]

I would contact a local machine tool supplier in your area and have them look for you. They will be able to get it for you if someone makes them.

If not, why not just use a typical end mill to do the counterbore? If you are working on a mill then you shouldnt have any problem getting the counterbore centered on the hole.

What exactly are you trying to do? If this is for a bearing pocket and you have a mill I would buy a boring head, you will have way more control over the finished size and one boring head will do a very large range of counterbore sizes.

[BigSki]

A milling operation is out of the question. I need to counterbore the narrowed axle tube on my Wraith axles for the bearing to have a place to seat. I've seen the SAE sizes, and there are a few that are close, but I just dont have the funds for a custom ground counterbore, especially when I'm only doing 2 holes.

My lathe is too small for the axle housing to pass through the jaws or it would be a simple lathe operation to make the pockets.

Aussie Nerds' idea is the one that I had when I first realized that ( it seems) that no one does makes what I am after. It might be the way I have to go.

[SMR 510RR]

Originally Posted by BigSki

A milling operation is out of the question. I need to counterbore the narrowed axle tube on my Wraith axles for the bearing to have a place to seat. I've seen the SAE sizes, and there are a few that are close, but I just dont have the funds for a custom ground counterbore, especially when I'm only doing 2 holes.

My lathe is too small for the axle housing to pass through the jaws or it would be a simple lathe operation to make the pockets.

Aussie Nerds' idea is the one that I had when I first realized that ( it seems) that no one does makes what I am after. It might be the way I have to go.

So what are you doing it in? Drill press?

[BigSki]

Originally Posted by SMR 510RR

So what are you doing it in? Drill press?

I need to do it by hand, hence the straight shaft counter bore. I tried using a big lathe at work today but the diffy housing still couldn't center itself inside of the jaw ( on a 12x34 lathe) so I need to come up with a plan 'C' .

I'm either going to get a small piece of oil slinthered bronze and make a rigid bearing or just setup a SAE CB and be done with it, I'll just have to run an odd-ball bearing on 1 side per axle. It's not the clean professional way to do it, but I'm not going to spend $$ on a custom cutter, it's just a damn toy after all.

[Charlie-III]

Originally Posted by BigSki

I need to do it by hand, hence the straight shaft counter bore. I tried using a big lathe at work today but the diff housing still couldn't center itself inside of the jaw (on a 12x34 lathe) so I need to come up with a plan 'C' .

I'm either going to get a small piece of oil sintered bronze and make a rigid bearing or just setup a SAE CB and be done with it, I'll just have to run an odd-ball bearing on 1 side per axle. It's not the clean professional way to do it, but I'm not going to spend $$ on a custom cutter, it's just a damn toy after all.

If it was me, I would get one that it a tad bigger than needed, then (by hand) grind it down to the correct diameter on a bench grinder. Since it's a hard steel, it takes a bit to remove material.

[chevellian]

Hey Walt, you could chuck up an 11mm drill in your lathe and carefully grind the tip down to 9mm with a dremmel.

Throw a rag over the ways, you dont want the grindings getting in there.