Slitting saw use?

[jon hill 3Participant @jonhill3]

Hi all

I am new to slitting saws and want to cut mild steel either on my proxxon ff400 (similar size to a sieg 1) or failing that on the myford speed 10.

There are a number of things I thought could be achieved such as  cutting T-nuts (saving all the tedious side milling on a small mill), also cutting say a 2mm deep slot in EN1A for a fingerplate project.  Whilst these objectives can be achieved in other ways I like to add to my experience base for future projects and can see some advantages in slitting saw use instead of a slot drill.

What cutting disks should I consider and is this achievable on my small mill?

[GazParticipant @gaz13336]

Hi Jon,

My experience of slitting saws is that they’re pretty much useless for anything other than slitting thin walled stuff i.e. collets etc. I find that the thinner blades tend to wander off their line, and it can be a right pain to use within the limits of the machine’s travel.

I do have a few, I think I have a 76mm x 2 blade and a couple of smaller ones but they really don’t get used much.

As far as using them to save time on a project such as t nuts, I doubt you’d save much as you’d still have to mill to finished size anyway.

Best wishes

Gaz

[Martin ConnellyParticipant @martinconnelly55370]

Slitting saws need a very well made arbor as any error in them, swash or concentricity, will cause problems. They also need plenty of torque at low speeds so a small mill is probably not ideal for slitting saw use.

Martin C

[Michael GilliganParticipant @michaelgilligan61133]

As per Martin’s comment … I think you would stand a much better chance of using saws successfully on the Speed 10 than on the little Proxxon

MichaelG.

[jon hill 3Participant @jonhill3]

Thanks Gaz, Martin & Michael

Sounds like using the Myford is the way forward.  What would be the ideal setup, presuming I have room bolting work to the speed 10 cross-slide? Are there MT2 arbours available or should I make a straight shank arbour and hold it in the dialled in 4 jaw?

[Howard LewisParticipant @howardlewis46836]

Whatever you do; do NOT use a key to drive a slitting saw.

If anything jams, the saw is likely to fracture and you will have sharp pieces of metal flying about.

As an Apprentice, I was almost injured by bits of a slitting saw that had been loaded with a key, by another Apprentice.

A thin slitting saw will wander if it is forced. Keep the depth of cut and the feed crate , low.

Howard

 

[Michael GilliganParticipant @michaelgilligan61133]

Many [surely not all ?] of the commercial arbors seem to be suspect … and Martin’s remarks are very relevant.

I would suggest making the important parts of your arbor in-situ on the lathe, whether you choose to use a straight shank or base it on a blank MT arbor.

MichaelG.

[JAParticipant @ja]

I use slitting saws with my own home made arbors. They still run eccentric. I suspect the stuff we usually buy is pretty poor.

Recently I cut through six 1″ x 1.5″ bronze bars using a 1/32″ slot cutter (don’t ask me why) without problems but it took a very long time. I am about to do a similar operation using a new saw from an industrial supplier.

JA

[Mike HurleyParticipant @mikehurley60381]

I thought it was me being incompetent, as I never had much luck with them, but perhaps not after all as I don’t seem to be the only one.

Good luck Jon

 

[JA]

On JA Said:

I use slitting saws with my own home made arbors. They still run eccentric. I suspect the stuff we usually buy is pretty poor.
[…]

There was a useful discussion about this on the old forum

… I will try to find it later.

MichaelG.

[John PurdyParticipant @johnpurdy78347]

I have quite a number of slitting saws,  from 2″ x .015 up to 3″ x 1/4 and some 4″ thinner ones, and I use them regularly on the mill for slitting and cutting things like forks in the end of rods up to 1/4″ wide by 1″ or more deep. Mind you the mill is larger, similar to a Myford VMC. They are mounted on home made mandrels that were turned in situ. even so almost all run somewhat eccentrically . Seems to be a very common problem. As stated, the thinner they are the more they tend to wander especially if fed too fast. The main problem I have is the lowest speed (220) on the mill is really too fast for the larger ones. I have a 3″x .048 that was used to cut the slot in the CI spindle head of Quorn. The tips of the teeth are no longer square but rounded. It was run too fast in the cast iron. As the name suggests they are intended for “slitting”,or “slotting”.

John

[Michael GilliganParticipant @michaelgilligan61133]

This is one of the old threads that I was hoping to find:

https://www.model-engineer.co.uk/forums/topic/sharpening-fine-tooth-slitting-saws/

Unfortunately, some of the useful photos, and links, seem to have failed to survive the journey to this new wonder-forum.

MichaelG.

[JasonBModerator @jasonb]

I suppose it depends what you pay, hopefully these Hoffman ones are fairly concentric running😯

One in action

[Michael GilliganParticipant @michaelgilligan61133]

Yup … that’s what they should sound like !

MichaelG.

[FulmenParticipant @fulmen]

Sharp slitting saws on good arbors work surprisingly well in my limited experience. But once they dull they become unpredictable. Those multi-size contraptions they sell are a joke, making a proper holder isn’t hard and well worth the time and effort.

[Dave HalfordParticipant @davehalford22513]

All my slitting saws are eccentric when run on the horizontal mill, all are good named ones of some age.

Some may have been re- sharpened etc, but I don’t see why so many (all) are out of true when cutter grinders are quite capable of edge sharpening end mills helix true and still be unable to get a 3″ slitter to run true.

One wonders if it’s more to do with manual feeds and piece work back in the day.

Is it just 1/32, 1/16 and 3/32 or does it include 1/8 and up?

[jon hill 3Participant @jonhill3]

What about some of the fixed on a  mandrel cutters, would they work better to cut up to 1/2 depth by say 5/64 in mild steel? I think there called woodruff cutters..

[Andrew TinsleyParticipant @andrewtinsley63637]

I must be lucky. All of my thin slitting saws work like a charm, even using the commercial arbours, which are said to be rubbish.

Could it be to do with the sharpness of the particular slitting saws that I happen to have? There must be some logical reason for the difference in performance.

Andrew.

[Harry WilkesParticipant @harrywilkes58467]

My Myford came with a load of extra’s including slitting saw blades I used one once mounted on a home made arbor without key slit a piece of steel 10mm thick went in 20mm without a problem

H

[HOWARDTParticipant @howardt]

Using slitting saws that are merely metal discs with a tooth form cut into the outside diameter should only really be used for shallow cuts, not much more than the depth of the tooth.  Beyond that depth the cutter can bind in the slot as there is no side relief and they then shatter.  Yes I have done that and got away with it more times than I should have, but have also shattered a few.  I make my own arbors out of mild steel and held in an ER collet holder.  The clamp is merely a located washer and a capscrew.  If you want to cut anything wider and deeper then use a small side and face cutter, they have relieved tooth form and will easily cut to the full depth the diameter allows.

[DiogenesParticipant @diogenes]

I didn’t know you could buy slitting saws that didn’t have relief ground in..?

[Diogenes]

On Diogenes Said:

I didn’t know you could buy slitting saws that didn’t have relief ground in..?

Those are probably [ like many things these days ] a ‘tribute’ to the concept.

… as JS was fond of saying ‘fit for purse’ if perhaps not ‘fit for purpose’

MichaelG.

[Mark RandParticipant @markrand96270]

Biggest problem I have is a motley collection of slitting saws and side & face cutters of 22mm , 1″ and 1 ¼” bore. I either need to make more arbors or make some adapter sleeves…

[Author]

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