# What hole cutters are used for thin walled tubing?



## disease (Nov 27, 2007)

I want to do a rudimentary setup of a frame for welding. I have a welder who will do the actual welding. I know that I can set up the whole layout on precision v-blocks on a flat surface. I am just going to use low quality tubes at first for the practice of going through all the steps of building a frame. 

I have access to a vertical milling machine. What I need is the proper type of hole cutter for cutting the tubes. Do frame builders just use any old steel/wood hole saw from a hardware supplier, or are there specialized precision tube cutters? The teeth on the stuff at Home Depot look far too large and jagged for precision results. Where do I get something appropriate for the task?

Which ones work best?

Which ones are a good value for a starter that is not ready to commit serious money, but wants respectable results?


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## Walt (Jan 23, 2004)

*Starret, Lennox, Dewalt*

Hardware store bimetal hole saws work fine. That's all I ever use. You'll need an adapter to get them to fit on your (presumably R8) milling machine. Paragon machine works sells those - www.paragonmachineworks.com.

Run slow (<100 rpm if possible) and make sure you have a good way to hold onto the tubes to cut 'em.

-Walt



disease said:


> I want to do a rudimentary setup of a frame for welding. I have a welder who will do the actual welding. I know that I can set up the whole layout on precision v-blocks on a flat surface. I am just going to use low quality tubes at first for the practice of going through all the steps of building a frame.
> 
> I have access to a vertical milling machine. What I need is the proper type of hole cutter for cutting the tubes. Do frame builders just use any old steel/wood hole saw from a hardware supplier, or are there specialized precision tube cutters? The teeth on the stuff at Home Depot look far too large and jagged for precision results. Where do I get something appropriate for the task?
> 
> ...


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## Evil4bc (Apr 13, 2004)

I prefer the Starrett fine tooth hole saws ,but some of the recent ones I have bought have chipped the teeth in strange ways.
So I started buying the Dewald ones from OSH , more from convenince but later realized that they were as true to size as the Starrett . 
From exsperince most of the Home depot Lenox hole saws arnt 100% round and not very true to size as far as O.D.


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## pvd (Jan 4, 2006)

Starret Bi-Metal 6-Pitch Sheet Metal hole saws with a Paragon arbor.

http://www1.mscdirect.com/CGI/NNPDFF?PMPAGE=1742


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## dru (Sep 4, 2006)

I expect that I'll be probably using my Dremel and files to cut mitres when I begin playing, but I was curious if a hole saw could be used in a drill press. A drill press is about as complicated as my shop gets. I have a vice on the press so holding the material isnt an issue. Could I use my drill press with hole saw bits for doing mitres?

Drew


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## 11 Bravo (Mar 12, 2004)

dru said:


> I expect that I'll be probably using my Dremel and files to cut mitres when I begin playing, but I was curious if a hole saw could be used in a drill press. A drill press is about as complicated as my shop gets. I have a vice on the press so holding the material isnt an issue. Could I use my drill press with hole saw bits for doing mitres?
> 
> Drew


There are many of simple tubing notchers out there. A quick search of Summit Racing came up with these ranging from about $70 to $250. In my opinion it is worth buying one unless you want the experience of notching with a file.

http://store.summitracing.com/egnsearch.asp?Ntt=notcher&N=700+115+4294852986&Ntk=KeywordSearch


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## disease (Nov 27, 2007)

Are the tubing notchers good enough for building a TIG welded frame with expensive tubing, or would the milling machine provide a much better result? The tube notchers look convenient and easy to use. Is it worth the trouble to do dedicated setups with v blocks on a milling table, or will the tube notcher results provide a miter that will result in a weld of similar quality?

Forgive me if I display my obvious ignorance of TIG welding gap tolerances.


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## Walt (Jan 23, 2004)

*Stay away from the expensive tubing for a while.*

If you need to ask this question, you should be ruining some straightgauge 4130 for a while. Stay away from the fancy stuff until you've got some hands-on experience and a couple of (townie/dirtjump/garbage) frames under your belt.

But to answer it, the method of mitering is far less important than the care used to make sure the miter is good. Can you fill small gaps with TIG? Sure, and you can do it with bronze too. That doesn't mean it's a good idea, though. Take your time and do a good job with every miter (this is probably going to include some final finishing by hand with a file, at least to deburr, and usually to perfect the miter as well) and you've got nothing to worry about. You don't need watertight miters, but the tighter and cleaner the miter, the easier joining the tubes will be and the better the resulting joint will hold up.

Tube notchers are very popular since they work with commonly available tools and are inexpensive. If used carefully, they can certainly produce an adequate miter. A milling machine is more useful to do miters *quickly* - the quality of the miter isn't necessarily any better.

Good luck!

-Walt



disease said:


> Are the tubing notchers good enough for building a TIG welded frame with expensive tubing, or would the milling machine provide a much better result? The tube notchers look convenient and easy to use. Is it worth the trouble to do dedicated setups with v blocks on a milling table, or will the tube notcher results provide a miter that will result in a weld of similar quality?
> 
> Forgive me if I display my obvious ignorance of TIG welding gap tolerances.


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## disease (Nov 27, 2007)

I will be putting in an order to Aircraft Spruce and Specialty soon!


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## Francis Buxton (Apr 2, 2004)

A good investment would also be a set of wood tubing blocks from Dave Bohm. These will allow you to hold your tubes in a vise securely while you file them. Get 3-6 good quality files (Nicholson or Grobet), a good hacksaw and a de-burring tool. The milling machine simply makes it faster.


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## BrendanC (Aug 11, 2005)

"Round" hole saws: I've had good luck turning my hole saws on the lathe & improving the OD a bit. I'd been using big, complicated tube notchers (and built on other additions to locate the tubes more quickly) for a while. They can get a good fitup, but the mill is undoubtedly faster.


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## disease (Nov 27, 2007)

BrendanC said:


> "Round" hole saws: I've had good luck turning my hole saws on the lathe & improving the OD a bit. I'd been using big, complicated tube notchers (and built on other additions to locate the tubes more quickly) for a while. They can get a good fitup, but the mill is undoubtedly faster.


I imagine you simply clamp the tube in the vise, using blocks with a circular cutout rather than a v groove, and then adjust the head angle of the mill to match the angle required for the miter?

Are there special tube holding blocks for this purpose, ones that will not crush the tube? I suppose I could simply make some according to the tubing diameter being held.


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## rmb (Feb 9, 2004)

disease said:


> I imagine you simply clamp the tube in the vise, using blocks with a circular cutout rather than a v groove, and then adjust the head angle of the mill to match the angle required for the miter?
> 
> Are there special tube holding blocks for this purpose, ones that will not crush the tube? I suppose I could simply make some according to the tubing diameter being held.


Yes, and these are the blocks FB was referring to:

http://www.bohemianbicycles.com/tchotchke.html


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## TacoMan (Apr 18, 2007)

I have always used a boring bar set to whatever radius I need. Makes it easy to take small cuts when fine tuing the exact gapless fit. Easy to resharpen.


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## pvd (Jan 4, 2006)

TacoMan said:


> I have always used a boring bar set to whatever radius I need. Makes it easy to take small cuts when fine tuing the exact gapless fit. Easy to resharpen.


really? do you rough cut with a hole saw first?


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## RoyDean (Jul 2, 2007)

Hougan annular cutters:










Kind of like a precision hole saw. A little pricey, though. Not really sure if they are worth it, but they are nice.


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## TacoMan (Apr 18, 2007)

pvd said:


> really? do you rough cut with a hole saw first?


Non-heatreated I just cut off square and rough with boring bar about .100 per cut. On thin large diameter heat-treated material I will rough on bandsaw first. Bandsaw blades last much longer than hole saws.

I like always being able to resharpen the cutting tool. Nice sharp tools cut clean with little burring.


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