Annular Cutter Purchase - Need Education

[Paul Alciatore]

I have some parts that need a nice hole in 1/8" +/- steel, unknown alloy, but it saws, files, and drills OK. I could probably use some circle saws that I have, but I am curious about annular cutters. They seem to make neater and more accurate holes and this seems like a good chance to get acquainted with them. I would be using them on either my 20" drill press or mill.

I am looking at McMaster and others and it seems like there are the cutters themselves, pilot pins, and arbors. And each of these is priced individually. I am not just concerned over the price here: individually priced items seem to indicate that some of them may not always be needed. So I have questions.

First, are all three of these items (cutter, pilot pin, and arbor) all needed in every application? I know the cutter is needed but what about the pilot pin and arbor?

They say the pilot pin also ejects the slug. How does that work? Is it spring loaded? Or do I need an additional spring? Or is there some other thing going on here? Is this something that is intended to allow their use in hand held drills?

It looks like some of the cutters have a round shank with Weldon flats for set screws. So they could be mounted in milling cutter holders? If I get and use an R8 holder in my mill, would I need an arbor? When is the arbor used? In a drill press or magnetic drill?

Those round shanks look rather short. But could they be mounted in a collet? Is there enough there for a good grip?

McMaster does not give the brand names for their products but the quality is usually good. MSC seems to have a lot of Hougen cutters and accessories: is that a good brand?

I need a good head start with these cutters.

[E189552]

Used a few of these in a specialized aerospace application. We made custom arbors, although the cutters were located by and operated through bushings. No center arbor used, mechanics would let 6 or so slugs accumulate before removing. Edges are like circular razor blades by the way. All aluminum materials, but it reduced the cutting forces significantly.
We used the Hougen brand exclusively.

[nickel-city-fab]

I've used annular cutters in mag drills for a couple decades now. Realistically, there is only two or three pilot pins you will need, that cover everything from (say) 1/2" up to (say) 2-1/2". Yes, the standard shank is 3/4" with two Weldon flats, You can get R8 holders for them as well as Morse holders. Actually they could even be shop-made quite easily. As far as the arbor goes, I've never seen one used, professionally.

Mag drill spindles are setup for the Weldon shank by default, so normally all you need is the range of cutters you want, and the pins to match. Practically speaking, you'll probably only need two pin sizes. When you drill your hole, the pin is "floating" inside the cutter and slowly going up inside the cutter, by an amount equal to the stock thickness.. When you retract the cutter from the complete hole, the back of the pin hits a hard stop inside the quill, popping the slug out of the cutter.

Strictly speaking, the pins aren't completely necessary, but they do make life much easier. The cutter will want to walk all over when you start a hole; the pins prevent that. You can dig out the offcut slugs with a needle nose, but its easier to just let the pin pop it out.

BTW they really like heavy sulfurized cutting oil like the plumber uses, most mag drills are fixed at 600 RPM.

Hope that helps!

[nickel-city-fab]

Forgot to add in my previous post, the shanks are usually 1-1/4 long IIRC. Lots of guys use them with collets. Be aware that there is a goodly amount of torque happening with these, you'll need to use a machine that has some decent low-RPM grunt, and you will need a holding system that really does have a good grip on the shanks. I consider the Weldon system to be the best for these, but lots of people get away with using good ER collets.

[754]

The pin not only ejects , but starts and stops coolant or cutting fluid flow. Often hooked to coolant say on a mill. On a mag base there is often a bottle that gravity feeds .. I'd you stop for 10 minutes without the pin the cutting oil could run out.
if you are lining up the point on the pin to a punch mark, you do not want coolant flowing.
1/8 is easy you can hand oil, but may need the pin to center the work under cutter.

[Video Man]

There's a good amount of torque on these, I have not been brave enough to try using a collet. Probably spin and ruin the collet. The arbors use two set screws at 90 degrees to each other, there must be a reason.

About the arbor and R8 end mill holder....the arbor is probably "correct" and the R8 holder, which I use, is my home-shop solution. Don't need both.
Some arbors are designed to inject cutting fluid inside the cutter, which is the way they are designed to be used on mag drills.

For my mill, I use an R8 holder but had to cut it back enough that the flat on the annular cutter shank would engage the setscrew on the holder. Not an easy job, but do-able. (Holder was hardened to some extent). External cutting fluid seems to work ok but I try to keep a continuous flow. If you have a set of cutters it will usually come with a couple sizes of appropriate pins, you don't need one for each cutter. They make life a lot easier removing the cutting slug. I bought a completely satisfactory set of Asian-made cutters with a good assortment of sizes, pins and a fitted case for remarkably reasonable price thru Amazon, might be worth a look. (Yes, I know very-expensive made in the good old USA cutters are probably better, spare me. It's a hobby shop and they work fine for me.)

[wierdscience]

I use them in the mill chucked straight into a 3/4" R-8 collet on a regular basis. No arbor or center pin needed on thin materials and I just use cutting oil dabbed on with a brush. If you decide to use them on a drill press, then you would need an arbor and the center pin.

TMX/Bison makes some good ones that are a mid point between Hougen and the China ones-

https://www.kbctools.com/CatSearch/36/annular-cutters

If the hole size isn't critical, a good quality holesaw on a homemade arbor in the mill works well on thin material, especially if the material can be tipped on a slight angle-

https://www.youtube.com/watch?v=Tgr9Jves3x0

[jcfx]

McMaster sells TMX or Hougen annular cutters, both are excellent, you're at the mercy of what's in stock when the order is picked.

If you need clean holes in relatively thin stock ( 3/8 - 1/2 " thick or less ) consider Blair Rotobroach cutters, they're literally baby versions of annular
cutters, I used them to cut holes for heating element standoffs in sheet metal for my vacuum former and in various projects
where I needed a clean hole. And they work in a drill chuck no special arbor needed and hand drills.

https://www.blairequipment.com/rotabroach-cutters

If you intend to use larger annular cutters on a drill press you'll probably need an annular cutter arbor for the drill press, on a mill you would need a r8 annular cutter
holder, I don't think a 3/4" tool holding collet would work on a mill for annular cutter, the annular cutters have two flats versus a weldon style shank that has
one flat, the two flats on the shank would seriously reduce the collets grip on the cutter .

So essentially you would need both a drill press arbor and a dedicated annular cutter holder on the mill so that you can move the cutters from one machine to another.
The arbor has a spring for the pin, and the pins are sized to the depth of the cutters, 1" pin for 1" depth cutter etc.

I would never consider using annular cutters in a hand drill except for the Rotobroach, like Video Man said they generate a lot of cutting force.

[Tundra Twin Track]

I have used them a lot in Milling Machine & Drill Press very little with MagDrill and have used with&without coolant through.In Drill Press extend quill as little as possible unless tight in the bore and should be sturdy.Start cut slow to allow groove to form to keep Cutter true and lots of lube.Ive used just the Cutter being held in TG 100 collets on Mill with no issues,slower for larger dia cutters.Arbor in pic is economical one at $66 cdn Accusize MT 2,3,4&R8 with internal Spring no coolant through.Once you use them your hooked,my favorite hole maker anything larger than 1" and holes are ROUND

[JRouche]

I have some parts that need a nice hole in 1/8" +/- steel, unknown alloy, but it saws, files, and drills OK. I could probably use some circle saws that I have, but I am curious about annular cutters. They seem to make neater and more accurate holes and this seems like a good chance to get acquainted with them. I would be using them on either my 20" drill press or mill.

I am looking at McMaster and others and it seems like there are the cutters themselves, pilot pins, and arbors. And each of these is priced individually. I am not just concerned over the price here: individually priced items seem to indicate that some of them may not always be needed. So I have questions.

First, are all three of these items (cutter, pilot pin, and arbor) all needed in every application? I know the cutter is needed but what about the pilot pin and arbor?

They say the pilot pin also ejects the slug. How does that work? Is it spring loaded? Or do I need an additional spring? Or is there some other thing going on here? Is this something that is intended to allow their use in hand held drills?

It looks like some of the cutters have a round shank with Weldon flats for set screws. So they could be mounted in milling cutter holders? If I get and use an R8 holder in my mill, would I need an arbor? When is the arbor used? In a drill press or magnetic drill?

Those round shanks look rather short. But could they be mounted in a collet? Is there enough there for a good grip?

McMaster does not give the brand names for their products but the quality is usually good. MSC seems to have a lot of Hougen cutters and accessories: is that a good brand?

I need a good head start with these cutters.

Very nice post and questions. I usually edit out the "fluff" from folks posts. I couldnt.

Hougen is some of the best.

Looks like weldon but probably a 5/8" shank. Adapters are avail.

Yes, they are spring loaded. Why? I dont know. It is not to eject the slug, it is a very light pressure. I think the pin it spring loaded to keep heavy hands from breaking them

The pilot is good for mag drills. On the mill or drill press I dont think they are completely needed. Always good to use when you can.

McMaster is notorious for not saying who the product is from. Dont like that. The deal is they always ship out what I think is top of the line, Always top shelf with those guys.

You will have fun. Those are good circle saws, saws, not drills JR

P.S. The 5/8" adapters are available, make yer own (and can I have one also please) . JR

[nickel-city-fab]

Hougen is one of the best brands, used to have them exclusively at work (glad it wasn't my budget...) Everything I saw was 3/4 shank, no springs in the pins. Dunno if it depends on the manufacturer or what. Either way you will want things clamped solidly. I was able to lean my full weight on the machine and the cutters didn't even grunt, they just took more DOC. I used to actually tack my workpieces right onto the table.

[Stepside]

If you have a secure set-up, you can cut 1/2 holes as welll other partial holes. With the correct size cutter you can make the "birdsmouth" for a pipe/tube joint. The accuracy is close enough to make a Silver Braze joint. The other day I used one to enlarge the arbor hole in a large circl saw blade. Slow speed and cutting fluid.

[Dunc]

Look on you tube for "annular cutter arbor". Several build it videos. I suspect that the big money is in the cutters not the add-ons.

[754]

J Rouche, I explained the function of the pin. When I was rotobroaching on the lathe , the slugs ejected thru spindle with enough force I had to build a catcher. That is 20 or plus inches from the work , clear thru the spindle and out the back.
if you don't run the ejector, you often spend more time removing slugs than drilling holes. Plus when the pin pushes up you get big coolant flow.. the cutters cost a bit to sharpen. Be aware not every one that sharpens them does a good job..

[true temper]

I bought a cheep r8 weldon endmill holder put it in the mill, put a piece of brazed carbide tool bit in the vise and faced off the holder till the annular cutter would go in far enough to reach the set screws.
I buy my cutters on eBay you can find some good deals on there.
I rarely use the pins even on mag drill they have a valve built in when pressed in coolant starts flowing.
I wouldn’t try to use them on a drillpress, not ridgid enough.
I wouldn’t think about using them on a hand drill. On a large dia. Cutter my magdrill is iffy if I can I clamp it down to prevent it from walking.
if drilling multiple layers you have to clean out each slug, before cutting the next one.
You will smile every time you use an annular cutter over a hole saw or twist drill.