Boring bar set input wanted

finsruskw

finsruskw

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looking into buying a boring head and bar set and would like some pointers on what to buy that will not break the bank.
Are the import sets pretty much junk??
Currently I have a HUGE #2 Bridgeport head that is an absolute monster that I doubt I will ever find a use for.
Thanks!
 
As far as boring heads go, I think the ones imported from China and India are worse than useless. A used name brand boring head will serve you well. I couldn't afford a Criterion, so I got a used Yuasa and am happy with it. For boring bars, buy or make what you need. I tend to avoid anything that comes in a "complete set" because some budget-strained component surely ends up being a complete PITA.

You can sell your big BP boring head to fund its more useful replacement. Replace quality with quality in a size you'll use.
 
Bridgeport had a couple different sizes of heads that are pretty much available on flea bay all the time. I always used a Bridgeport head so I'm partial to them, but you can do everything the small head does with the one you already have, so why waste your money on another.
 
I have a set of BORITE cobalt bars that are pretty good but they are not cheap. I actually use them quite a bit on the lathe, as I don't bore on the mill that much.

www.travers.com

Premium Cobalt Boring Bars & Sets

BenefitsProvides less chatter than carbide tipped tools.Provides better tool life and a better surface finish.ApplicationsUse for applications where long production runs or heavy duty machining is involved. It is also much easier to re-sharpen.Recommended for adverse machining conditions...
www.travers.com www.travers.com
 
I am using a 2.5" boring head with R8 taper from Grizzly that works quite well.

Its undoubtedly import but it works well.
 
If it were me, I would buy a Criterion DBL-202A head and Borite or some other 3/8" cobalt boring bar set to go with it. The DBL-202A takes 3/8" shank bars that weigh less and given that mass matters when boring, the smaller bars allow you to go bigger with less vibration. Has to do with Centripetal forces.

DBL-202B heads that take 1/2" bars is also okay. I just prefer lighter bars. I also prefer to use the lightest head I can get away with for the job.

I own an Interstate clone of the DBL head and its okay, just not of the same quality so I don't use it. A bunch of us bought one for $20.00 each some time back and it was a screaming deal for what it was but I still feel that a better use of your money is to wait for a good Criterion head to come up on ebay.
 
Something along these lines??


  • FTS-GE601100A
  • Bridgeport Boring Head Sets
  • Criterion Machine Works has made available a number of boring head sets specifically selected for Bridgeport Mills. These sets include a standard Criterion Boring Head with an R-8 shank and a wide range of boring tools and boring bars. The boring tools are available in high speed steel or in either a C-2 or C-6 grade of carbide. C-6 Standard, C-2 by special order only.
 
The cheapest way to get a Criterion head is to buy it on ebay. I don't know what your budget is but a 2" head that is in good shape under $200.00 is not bad. A brand new head cost $300+ but these heads can go for decades if they are cared for and a used one in good shape is okay for hobby shops.

As I mentioned, a DBL-202A head is a better head in my opinion. They are also harder to find and tend to cost more to buy. Here is one that looks to be in good shape. You can see that all three bar holding screws are there, the dovetail gib looks intact and I can see the center gib screw. I cannot see the two outer gib adjusting screws but you can ask the seller to check for you. Under each of these gib adjusters is a ball bearing; the screws and ball bearings need to be there. If you do buy a DBL head and need to know how to adjust the gib screws, give me a shout out.

The DBL-202A can bore a hole from 0.050" to 3.00" using the bottom holes and can go out to 6.687" with the horizontal outboard hole. The bigger you need to go, the slower your mill must be able to run. If you need to go beyond 6" then you need a bigger head and a bigger mill.

All DBL heads have removable shanks with a 7/8-20 thread inside the top of the head. Adapters are easy to find and you just need an 7/8-20 to R8 adapter to fit your mill.

There are several cobalt boring bar sets on ebay but a better buy is the set from Little Machine Shop. The set has 8 bars and is made from 5% cobalt. It should work for you. I would avoid cheap brazed carbide bars and inserted carbide bars for now. The cobalt set will cut better and finish finer at speeds the head will run well at.
 
The Chinese sets ofboring tools work ok after you grind proper relief angles.
 
Thanks for the input folks.
I missed the one on e-bay last night, went way higher than I was prepared to bid.

I think I'll try to find a bar w/5/8" shank and see what I can screw up using the #2 Bridgeport head I do have.

So, I guess I in the market for some decent 5/8" bars.
 
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