Reamers

[Steve HuckinsParticipant @stevehuckins53362]

I note that hand reamers are cheaper than chucking reamers.  I have also seen posts that say you can use hand reamers on the lathe or mill as long as you are careful.  Since model engineering uses such a large range of reamers then buying them is obviously quite costly.  What is the overall opinion about this subject ?

Regards

Steve

[Matt TParticipant @mattt]

I used a hand reamer in my tail stock. I cant speak to the wear on it but since I use it very occasionally I don’t see it as much of an issue. The main thing is the longer lead in that hand reamers have. If you don’t go through enough you’ll end up with a tapered hole, also for blind holes you may issues. Going forward I’m buying machine reamers as they aren’t much more and don’t have the same lead in, the taper on my flywheel made it an accidental press fit lol

[JasonBModerator @jasonb]

I don’t think there is a lot in it price wise, I’ve gone over to using machine reamers as I find them less prone to chatter than a hand reamer when used on a machine, most likely due to the small (end) cutting area of a machine reamer and the considerably larger (tapered) lead of a hand reamer.

Also if reaming a hole in a part on the lathe you don’t need to drill your pilot hole excessively deep to be able to ream with a machine reamer, usually the parting allowance is enough to clear the chamfered end.

[Howard LewisParticipant @howardlewis46836]

Hand Reamers have a longer lead in taper than machine reamers, so may not ream to size asd ar down a blind hole.

A Machine Reamer will have a Morse taper shank, so should be held more accurately in the Tailstyock.

Holding a hand reamer in a drill chuck in the Tailstopck, or the spindle of a Mill, leaves you open to whatever eccentricity there is in the drill chuck.

An off centre reamer will act like a boring bar, and remove more metal on one side than the other, leading to an oversize hole.

A Hand Reamer can be centred more easily by locating the end with a centre in the tailstock of the lathe

[JAParticipant @ja]

I have used hand reamers in a tailstock but I think it is unwise. How concentric is the shaft of the reamer with the cutting faces? I have seen hand reamers used with a centre in the tailstock which makes more sense but needs a little bit more skill.

Generally I use machine reamers but hand reamers do have their uses such as using the taper of the hand reamer.

JA

[JasonBModerator @jasonb]

All my machine reamers are parallel shank and often get held in a ER collet chuck in the mill or lathe though I do sometimes use a drill chuck to hold them, engines seem to run OK with that.

[EmgeeParticipant @emgee]

Loke Jason most of my reamers are chucking type and H07 so you do end up with clearance for a spindle/rod of the same diameter, other specs are available to provide interference on the same diameter spindle as the reamer.

If you are confident the tailstock is trult aligned and there is minimal runout in the chuck/collet you should end up with a truly sized reamed hole, you do of course have to allow a small allowance in the drilled hole for the reamer to work.
It is always best to bore the hole before reaming for absolute accuracy as all sizes of drills can wander in the hole.

Another point when reaming some materials is you may experience different results in hole size cutting dry and when using cutting oil or other lubricant when reaming the hole.

Hand reamers can sometimes be useful if you want the reamed hole slightly undersize at one end, just don’t pass the reamer totally through the hole, stop so the taper part is still within the bore.

Emgee

 

 

[VicParticipant @vic]

I recently bought a set if chucking reamers from Amazon, very reasonably priced.

[VicParticipant @vic]

I recently bought a set of chucking reamers from Amazon, very reasonably priced.

[Chris CrewParticipant @chriscrew66644]

I use mostly hand reamers with a tap wrench when on the bench and in the tailstock chuck when on the lathe. I drill 1/64″ undersize and finish with the reamer. In the lathe I use the lowest possible speed, grasp the tailstock firmly and push it along the bed until the reamer stops cutting and then pull the tailstock back along the bed with the lathe still rotating. I usually put a few drops of Rocol RTD on the reamer when working steel. It seems to work for me and for the work I do.

[JAParticipant @ja]

I believe chucking reamers are a recent innovation brought about by industrial CNC machine centres. I certainly never met them in the first half of my life but now have two or three. Looking at an industrial supplier’s web site (Drill Service Horley Ltd) it appears that most are Carbide, not High Speed Steel.

JA

[John PurdyParticipant @johnpurdy78347]

Chucking reamers are not new, they have been around for over 100 years.  My copy of “Machine Tool Operation” dated 1919 describes them in the section on reamers ( along with, shell, hand, adjustable, expansion. and taper).

I have both chucking and hand reamers and use the chucking ones most of the time both in the mill and in a floating reamer holder in the lathe tail stock (and occasionally in the drill press). All mine are parallel shank and are held in ER collets since the shanks are odd diameters. As has been said before they have the advantage that they will ream full size to the bottom of a blind hole (minus the short 45 degree taper of the cutting edges on the end).

From the major tool suppliers in this country HSS chucking reamers  generally cost about half or less than the price of hand reamers  (the parallel shank ones not Morse taper ones). Just checked and from one supplier a 1/4″ chucking reamer is $17 and a 1/4″ hand reamer is $48!

John

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