Counterboring titanium?

K

Kahr9mm

Joined
Oct 22, 2011
Messages
28
Hi all,

I apologize in advance if this has already been posted. I am trying to find a good way to effectively counterbore .288 pivot screws into .138 thick titanium handle scales and bolsters on my folder. Before I plunk down the cash for some decent HSS counterbores, I wanted to check with you guys first because I'm leery that the Ti may eat the CB's up. I've read and heard that you can counterbore larger diameter holes in titanium using standard HSS counterbores, going *very slowly,* and using very low RPM's on a drill press or mill. FWIW, I will be using a basic drill press for this task. I just don't want to spend a lot of cash on basic HSS counterbores and end up ruining them and the handles/bolsters if there is a more effective (and accurate) way to do this.

P.S. It's kind of crude, but I have actually counterbored using a standard drill bit. Obviously it's not as accurate because there isn't a pilot and the bit has a tendency to "wander" off center.

P.P.S. Are cobalt drill bits more effective in drilling titanium than say HSS or black oxide bits?

Sorry for the ramblings. Just hoping you guys/gals might be able to give some sage advice on this.

Thanks much,

Michael
 
We recommend using an end mill and a rotary table rather than a counterbore. We've found counterbores to be inaccurate. If your mill head is not square, the hole and recessed area will not be square to the scale. Using a rotary table eliminates this potential problem. Use a smaller end mill than the pivot head and rotate the table to make any size hole or recess you need.

Chuck
 
Chuck, sure glad you put that last sentence in your post. I was trying to figure what purpose the rotary table served with a mill and endmill. Question: "IF" you have the size endmill required for counterbore, would this work as well? OR - is it preferred to use a smaller size endmill and rotary table?

Maybe this is the excuse I've been looking for to order a rotary table {g}

Ken
 
Chuck and Ken,

Thank you for the replies. Chuck, I think I understand what you are saying about using an end mill and rotary table in lieu of the counterbores on Ti. Unfortunately, I don't have access to an end mill--I just have a drill press to use (nothing fancy). Is there any way to accomplish what you are describing by using the drill press? I know it's probably a long shot. :)
 
As Frank says, with a drill press a counter bore is your best bet. I suspect many makers with milling machine and end mills use counter bore.

Ken H>
 
I'd like to use a counterbore, but do you think it will cut through titanium without too much issue?
 
Titanium is no problem for an HSS counterbore but, as Chuck said, squaring could be. Use a pilot if you can, too.

Mark
 
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Kahr9mm said:
I'd like to use a counterbore, but do you think it will cut through titanium without too much issue?
Click to expand...

I've used a counterbore with pilot many times and used the same one many times on titanium. It's starting to get dull now but thats after several knives. If you don't have a pilot on the counterbore you can also use a countersink to widen the hole you want to counterbore to the width of your counterbore so it doesn't slip around and stays centered. This is a very primitive way of doing it compared to what Chuck recommends and not the easiest way but, in a pinch I've done it with success. I've since invested in a mill and rotary table but everyone has to start some place so I understand exactly where you are coming from.
 
Thank you, guys! I think I'm going to try the counterbore with a pilot route and see what I can do. My pivot hole is 3/16" and I'll be basically counterboring to 5/16". Through this process of learning, I've discovered mini-mills (such as the Micro-Mill, Grizzly, and Harbor Freight models).

I've read that buying a decent milling machine is a better investment than buying a bigger drill press. Any thoughts on this? Thanks again, guys!
 
A milling machine is a totally different tool than a drill press, no matter how large the drill press is. I put off buying a mill for a couple yrs, just didn't think I'd have "that" much use for it. Now I got a mill, it's just like the lathe, how did I get by without it?

Ken H>
 
Kahr9mm said:
Thank you, guys! I think I'm going to try the counterbore with a pilot route and see what I can do. My pivot hole is 3/16" and I'll be basically counterboring to 5/16". Through this process of learning, I've discovered mini-mills (such as the Micro-Mill, Grizzly, and Harbor Freight models).

I've read that buying a decent milling machine is a better investment than buying a bigger drill press. Any thoughts on this? Thanks again, guys!
Click to expand...

I have found in the last 6mos I've been making and selling knives just because I have a mini-mill doesn't mean I don't need a drill press. My original thought before purchasing my mill was, I would get one and it would illiminate the need for a drill press. Boy was I wrong!!! My mill was converted to CNC by the previous owner and I set it up the same way so it's not like i can manually drill something easily. I've burned up more drill bits than I care to remember trying to use the mill as a drill!!! So, I just recently purchased a new drill press which I've been real happy with so far. If your in need of a decent drill press and don't want to spend $1000, check out Steel City. They have a 13in with digital speed and depth readout which I've added a keyless chuck too. Great little press for under $400.
 
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