6mm reamer speed

[Dave CeeParticipant @davecee80929]

Got to drill a 5.9mm hole then ream.

Never used a reamer before. My guess was going to be 1000rpm for the drill and half that for the reamer?

Material is normal steel.

Thanks

Dave.

[Dave CeeParticipant @davecee80929]

[peak4Participant @peak4]

I think you might want to slow down a bit with the reaming. Have a look HERE

Also is your reamer a machine reamer, likely with a Morse taper on the end, or a hand reamer, with a square on the end to fit a tap wrench.?

Regards

Bill

[Dave CeeParticipant @davecee80929]

Thanks Bill.

It's a reamer to use in my drill press. I just wanted to know the RPM to use. Thanks for the Link but at the moment all that SFM is a bit double dutch to me.

Dave.

[Anonymous]

For a 6mm machine reamer I'd drill 5.8mm; reamers need to cut not rub. A rule of thumb for machine reaming is half the speed and twice the feed compared with drilling.

Andrew

[peak4Participant @peak4]

Posted by Dave Cee on 03/02/2017 12:04:15:

Thanks Bill.

It's a reamer to use in my drill press. I just wanted to know the RPM to use. Thanks for the Link but at the moment all that SFM is a bit double dutch to me.

Dave.

Dave, ignore my link anyway, I'm obviously half asleep. Not enough coffee yet, they were for carbide tipped reamers.

[JasonBModerator @jasonb]

Like Andrew I drill 5.8mm but check that your 5.8mm is not cutting oversize.

I'd run at about 100rpm be it a hand or machine reamer.

[mechman48Participant @mechman48]

Have a look at …

**LINK**

George.

[mechman48Participant @mechman48]

Also have a look at …

**LINK**

Also simplified formulae…

Spindle speed (n) – metric

rpm
​

 

rpm –  imp.

 
Where…

Parameter	Meaning​	Metric unit​	Inch unit
DC​	Drill diameter​	mm​	inch​
vc​	Cutting speed​	m/min​	ft/min​
n​	Spindle speed​	rpm​	rpm

 Then using rule of thumb … reaming speed = 50% drilling speed , should get you in the ball park with reasonable results

George.

 

 

 

 

 

Edited By mechman48 on 03/02/2017 13:34:53

Edited By mechman48 on 03/02/2017 13:38:17

[not done it yetParticipant @notdoneityet]

My advice would be to learn how they are derived, for the longer term.

 

 

But for starters you could commit to memory one value and expand from there. Say 10mm, if metricated, and perhaps half inch if using antiquated units. Pick a material such as mild steel, or your most oft used material.

 

 

All you then need to remember is to double the speed if you halve the diameter or halve the speed if you double the diameter for the same material. Other sizes will also be in the similar ratios.

 

Then consider the material either slower or faster Aluminium twice, or more than mild steel, per eg, or perhaps only half for tougher steels.

 

Then factor in the tool material – like double up (or more) the speed for carbide over HSS cutters or tool type (halve for reamer over the drill).

 

Gradually you will build confidence in choosing a cutting speed. Dry cutting should be slower than lubed or cooled – and CNC will be another completely different ball game! Remember that slower is generally better for tool life. Just don't allow it to chatter when lathing or milling and don't stop in one position when cutting anything (or the tool will rub, get hot, go blunt, etc).

 

Hope that helps.

Edited By not done it yet on 03/02/2017 13:50:26

[EmgeeParticipant @emgee]

Peak4

Plus 1 for 100rpm. I always use a cooling or cutting fluid when reaming steel.

DON'T turn the reamer backwards or you can/may/will damage the flute(s)

Emgee

[Anonymous]

On the basis of half the speed for a reamer I'd ream at 500rpm without coolant on the vertical mill. To go lower is a PITA as one needs to engage backgear, and remember to flick an electrical switch to reverse spindle direction. On the lathe I'd use 370rpm (nearest below 500rpm). I'd also use coolant on the lathe as it's convenient – one button to push.

Andrew

[Neil WyattModerator @neilwyatt]

rpm = feet per minute x 4 / diameter in inches

The exact calculation for 1/2 " cutter at 200 fpm is:

(200 * 12) / (0.5 * PI) = 1528 rpm

The approximation gives:

200 x 4 / 0.5 = 1600 rpm

For metric

rpm = metres minute * 300 / diameter in mm

The exact calculation for 12mm cutter at 70 metres/minute is

(70 x 1000) / (12 x PI) = 1,857 rpm

The approximation gives:

70 x 300 / 12 = 1,750

While you can set 'exact' speed with a VFD or similar, for a century or more people managed fine using belts with a series of fixed speeds and those approximations will always get you in the ballpark.

In the 'real world' experienced machinists will compensate for blunt cutters,, hard materials, flimsy machines and the phase of the moon by tweaking speed up and down. The real test is always 'is the cutter working happily', bearing in mind that a cutter used too cautiously will blunt almost as quickly as one that is overworked.

[JasonBModerator @jasonb]

My reason for suggesting 100rpm is that most of my reamers are hand reamers though mostly used under power so its a compromise between faster than I could ever hope to turn them by hand but maybe slower than the suggested speed for machine reamers.

Turn of the vari-speed knob is all I have to do to change the speed. A drop or to fwo of cutting fluid, CT85 is the current tipple.

[Anonymous]

Posted by JasonB on 03/02/2017 15:11:08:

My reason for suggesting 100rpm is that most of my reamers are hand reamers……

Ah, all bets are off then. All my reamers are machine reamers, and that's what I was quoting for.

Andrew

[JasonBModerator @jasonb]

Which begs the question are there any differences between the flutes of hand reamers and machine ones once past the tapered end of the hand reamer that may or maynot prevent them being used as fast as machine reamers. Anyone know?

[John Stevenson 1Participant @johnstevenson1]

No idea Jason but one thing I do know is there is a difference in lubrication.

If I ream a hole using soluble fluid it will be tighter than using neat cutting oil, only tenths but try it with a dowel pin to check.

It's a quick and dirty way to dial in a hole.

[Anonymous]

Posted by JasonB on 03/02/2017 20:52:57:

Which begs the question are there any differences between the flutes of hand reamers and machine ones once past the tapered end of the hand reamer………….

Probably not, but since neither type does much cutting on the parallel flutes it wouldn't determine cutting speed. I expect that a hand reamer would be more prone to chatter as it is cutting over a much greater length along the tapered flutes. So a lower speed may help reduce chatter, much as for a countersink.

Andrew

[Dave CeeParticipant @davecee80929]

Thanks for all the replies.

Will learn the sfm too

[Dinosaur EngineerParticipant @dinosaurengineer]

I notice on mecman's post link that Presto states all reamers are now made to H7 tol. What happened to the H6 grade ?

Edited By Dinosaur Engineer on 04/02/2017 19:14:54

Edited By Dinosaur Engineer on 04/02/2017 19:15:25

Edited By Dinosaur Engineer on 04/02/2017 19:15:49

[mechman48Participant @mechman48]

I think I'll stick with Presto's info as BS reamer standards are a bit beyond my pocket …£190 a pop!…

FWIW a bit more info …

http://www.standardscentre.co.uk/bs/BS-328-4-1983

http://www.frscott.co.uk/downloads/t—presto-3-reamers.pdf ……

this identifies DIN ref's for different materials when reaming.

​also an example that specifies H7 hole size … http://www.stimzet.cz/endata/csn221431c_gb.html – DIN 208

http://www.stimzet.cz/endata/csn221430c_gb.html​ – DIN 212

​… it depends how close & tight ME's want their tolerances to be… as for me H7/h6 does me fine

George.

Edited By mechman48 on 05/02/2017 14:39:58

Edited By mechman48 on 05/02/2017 14:56:18

[Neil WyattModerator @neilwyatt]

Has anyone ever tried chopping the end off a hand reamer (perhaps damaged on the tip) and regrinding it as a machine reamer?

Shouldn't be too hard, except that you'd need to index directly from the tooth being ground as reamers sometimes don't have evenly spaced flutes

Neil

[Dave CeeParticipant @davecee80929]

Found this also.

https://www.wisc-online.com/LearningContent/mtl8202/MLT8202.htm

Edited By Dave Cee on 05/02/2017 21:31:42

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