Sieg x2D making a hole in steel

[hman]

I've used hole saws in steel at various times. Do-able, but difficult. As you've noted, they love to load up with chips and get bogged down. I just recently "discovered" annular cutters. They're a real joy to use!!! The chips are efficiently removed by the flutes on the outside, the sharpness of the cutting teeth means less power is needed than for a hole saw, and the finish is very good. If you can afford one, you'll find it worth the cost.

I'm pretty sure this is the one I have ... $39 ... hold in a 3/4" collet, use lots of lubricant:

Amazon.com

 

[homebrewed]

Not sure why you guys think it will take a "zillion" passes to open up a hole. We're only talking about a 1-1/4" hole so the head is not going to be extended very far and balance issues should not be that big a deal. Therefore, you can keep speeds up a bit and the cut goes quicker. A boring head is capable of taking fairly big cuts, on the order of 0.025" or more with steel bars before deflection of the bar becomes an issue; you can go deeper with a carbide bar. I am referring to roughing cuts here but you will be reducing cuts to come in on size.

You need to see what the set up allows; each mill and head/bar combination is different for a given material. Set a depth of cut and speed and give it a try, then increase your depth of cut to see what the set up tolerates. It shouldn't take very long at all to bore out a small hole like that.

Starting from a 1/2 inch hole, the biggest drill the X2's chuck can accommodate, makes for a lot of passes. Perhaps I've been too conservative on the DOC I use? I know that my mill really notices anything much more than .01" at a time when using the boring head. Maybe it's the cutters I'm using, pretty vanilla brazed carbide boring bars.

 

[mikey]

Starting from a 1/2 inch hole, the biggest drill the X2's chuck can accommodate, makes for a lot of passes. Perhaps I've been too conservative on the DOC I use? I know that my mill really notices anything much more than .01" at a time when using the boring head. Maybe it's the cutters I'm using, pretty vanilla brazed carbide boring bars.

As I said, every mill and head combination is different. I also occasionally use those cheap Chinese boring bars to bore steel plate but mine have been honed and sharpened over a 30+ year period and cut well. I use a Borite cobalt set of bars for fine boring and they are hard to beat in a boring head. I own but rarely use inserted bars in a boring head.

I think the head also makes a difference in how well the set up works. For smaller holes, I prefer a Criterion S-1-1/2 head. It is small but has a relatively large dovetail bearing surface so it is very rigid for its size. It will take a 0.025" depth of cut in mild steel plate on a Sherline mill and more on my RF-31 using those brazed bits. My DBL202A or B head will go deeper. However, this is on my set up and yours will differ; you have to see what your limits are.

The depth of cut you can take accurately is different from the depth of cut you can take roughing. This has to do with the bar material, how sharp it is, and your cutting conditions. I find that with carbide bars, I have to run faster but there is a limit to how fast you can go because centripetal forces increase with speed; doubling the speed increases centripetal forces by a factor of 4 so balance becomes a real issue with speed. That's why I said you gotta' try it and see how big a cut you can take at what speed in order to see what you have to work with.

I also prefer boring heads that take lighter/smaller bars. I have two Criterion S-1-1/2 heads and two DBL-202 heads; one of each can take 3/8" or 1/2" shanked bars. If I have to go deeper, I use the 1/2" bars. If I have to go to a larger radius, I use the lighter 3/8" bars because mass also affects centripetal forces and that limits how big I can go with the speeds I have.

Boring gets complicated sometimes, especially if you have to be accurate. Boring a hole in a plate is usually no big thing but boring one in a casting to tight tolerances ... yeah, that can be a very big thing. To do that, you have to know your head, your bars, understand how centripetal and cutting forces work and how your mill handles all of it. Only then does accuracy become easier to achieve.

I did not mean to imply that you're taking wimpy cuts; far from it. I meant that in order to know what your mill and boring set up can do, you have to test it and see.

 

[homebrewed]

As I said, every mill and head combination is different. I also occasionally use those cheap Chinese boring bars to bore steel plate but mine have been honed and sharpened over a 30+ year period and cut well. I use a Borite cobalt set of bars for fine boring and they are hard to beat in a boring head. I own but rarely use inserted bars in a boring head.

I think the head also makes a difference in how well the set up works. For smaller holes, I prefer a Criterion S-1-1/2 head. It is small but has a relatively large dovetail bearing surface so it is very rigid for its size. It will take a 0.025" depth of cut in mild steel plate on a Sherline mill and more on my RF-31 using those brazed bits. My DBL202A or B head will go deeper. However, this is on my set up and yours will differ; you have to see what your limits are.

The depth of cut you can take accurately is different from the depth of cut you can take roughing. This has to do with the bar material, how sharp it is, and your cutting conditions. I find that with carbide bars, I have to run faster but there is a limit to how fast you can go because centripetal forces increase with speed; doubling the speed increases centripetal forces by a factor of 4 so balance becomes a real issue with speed. That's why I said you gotta' try it and see how big a cut you can take at what speed in order to see what you have to work with.

I also prefer boring heads that take lighter/smaller bars. I have two Criterion S-1-1/2 heads and two DBL-202 heads; one of each can take 3/8" or 1/2" shanked bars. If I have to go deeper, I use the 1/2" bars. If I have to go to a larger radius, I use the lighter 3/8" bars because mass also affects centripetal forces and that limits how big I can go with the speeds I have.

Boring gets complicated sometimes, especially if you have to be accurate. Boring a hole in a plate is usually no big thing but boring one in a casting to tight tolerances ... yeah, that can be a very big thing. To do that, you have to know your head, your bars, understand how centripetal and cutting forces work and how your mill handles all of it. Only then does accuracy become easier to achieve.

I did not mean to imply that you're taking wimpy cuts; far from it. I meant that in order to know what your mill and boring set up can do, you have to test it and see.

Good information on tooling, thank you!

 

[Weldingrod1]

The chip relief holes when hole sawing are a night and day change! I highly reccomend this trick!

The less material you convert to chips the faster you get to your finished part. Thus, the hole saw is attractive... annular cutters chip more metal but can do continous feed IF you've got the torque.


Sent from my SM-G892A using Tapatalk

 

[Ken from ontario]

I have used larger size silver and Deming bits (with 1/2" shank) to enlarge a hole in Aluminum, it gets me to the final diameter faster but I must admit never tried it on 5/8" steel plate.

 

[snorky]

I thank all of you for the great selection of answers. I tried a "no-name" boring set and proceeded to blow a fuse when the dial gauge couldn't decide to use the same measurements with a turn of the dial. Sometimes .008 turned into something must bigger. Gave up trying to figure it out. And I did know that it was radius not diameter and backlash was not an issue. On to something a bit better.

 

[ericc]

You're lucky you didn't strip a plastic gear. If you keep experimenting with a flaky boring head, it might be a good idea to replace that fuse with a much smaller one, preferably bought by the dozen. I hate stripping gears accidentally.

 

[snorky]

You're lucky you didn't strip a plastic gear. If you keep experimenting with a flaky boring head, it might be a good idea to replace that fuse with a much smaller one, preferably bought by the dozen. I hate stripping gears accidentally.

Amen to that. I got the right fuse and everything worked fine. God watch's over fools and idiots
I did discover that the bars were chipping and not being held securely in the head. Because I am EXTREMELY impatient, I put in one my my lathe 3/8 inch indexable boring bars and proceeded to continue. To my delight and surprise the machine acted like it liked it and I was able to get it close enough to call it quits. I would rather machine the shrinking collet going into the hole (I still need to finish the relief cut) than get the hole too big. It worked well. I didn't push it like Mikey suggests because I know that this was not the best thing to do. But I might get a 1/2 indexable boring bar and shorten it so as not to flex as much.
Thanks to all for the comments

 

[mikey]

I didn't push it like Mikey suggests because I know that this was not the best thing to do.

No pain, no gain! If you don't test your set up then you will never know what works and what doesn't. A good boring bar in a properly set up boring head does not produce all that much cutting force and even a small mill is capable of much more than you might think. Just saying ...