Best Parting off tool

[richard 2Participant @richard2]

Have just read all the blurb on the Eccentric Engineering parting-off tool so am asking what other people think?

I know there are a great many opinions and threads on this subject but I do like to ask before I spend a fair amount of money.

My lathe is a Myford Super 7B with two rear tool posts – one a Myford which is a heavy block and the other is home-made taking a QCTP.

Have looked at other makes and need a new p/o tool for the rear tool-post

So suggestions, please.

Many thanks

richard 2

[richard 2Participant @richard2]

Ask and ye shall receive…..

[blowlampParticipant @blowlamp]

Keep to a narrow tool on that size of lathe. I use a 2mm wide GFN style insert with positive rake geometry on my Mini-Lathe from the front toolpost, with no issues, so it should be fine with your setup.

Martin.

[Mick B1Participant @mickb1]

I use a Chronos (I think) holder with a 1/16 x 5/16" HSS blade.

It's cheap, adjustable, and easily does everything I can remember up to maybe 2 1/2" diameter – wood, delrin, brass, phosphor bronze, LG2, BDMS, titanium, silver steel. I can't see that I'd want anything better unless I started making batches of several tens or more – and then it wouldn't really be a fun hobby, would it?

[egaParticipant @ega]

Gary of Eccentric Engineering makes a persuasive case for his Front or Rear p/o toolholder. I bought one for use on my larger lathe but found the 2mm blades I opted for rather fragile and pricey (I believe he offers blades down to 1mm wide). I am now using a tangential insert tool from ISCAR.

On the Myford, I long ago made the GHT rear toolpost and, by and large, it does everything I need. I had one of the KIT-Q-CUT insert tools from Greenwood Tools for a time; this worked well but I found the cost of replacement blades uneconomic.

My personal preference is for p/o tools with minimum overhang on the Z axis.

Edited By ega on 05/12/2017 18:01:14

[egaParticipant @ega]

Mick B1:

Your impressive feat of parting off 2.5" dia silver steel with that blade makes the point that the "best" toolholder/blade and/or insert combination will be of little use on an unsuitable or badly-adjusted lathe; speeds, feeds and lubrication are also important.

Edited By ega on 05/12/2017 17:58:39

[Neil WyattModerator @neilwyatt]

Greenwood have a new replacement for the Kit-Q-Cut coming soon, hopefully some news in the next MEW.

Neil

[egaParticipant @ega]

Posted by Neil Wyatt on 05/12/2017 18:09:20:

Greenwood have a new replacement for the Kit-Q-Cut coming soon, hopefully some news in the next MEW.

Neil

I shall read this with interest as I always thought the original design was rather basic. I hope the news will include information about the reasons for any changes.

[Mick B1Participant @mickb1]

Posted by ega on 05/12/2017 17:57:08:

Mick B1:

Your impressive feat of parting off 2.5" dia silver steel with that blade makes the point …

Well, I didn't mean to exaggerate, but I don't think I've ever seen 2.5" silver steel – that just got into the list through sloppiness on my part. But I have parted 60mm. EN8, and that can be quite argumentative…

[VicParticipant @vic]

I like the T shape blades that Chronos sell.

**LINK**

They are the best parting blades I’ve used to date and I no longer feel the need to use expensive insert parting tools anymore.

[Geoff TheasbyParticipant @geofftheasby]

I've just bought a Chinese tool costing £10, using MGMN200G inserts. I considered Greenwood, etc., but £70 is a lot to pay if it doesn't work. Even the competition at £30 is quite dear.

Geoff

[MuzzerParticipant @muzzer]

APT Tools also stock various MGMN-type grooving / parting tools in various widths from 1.5mm to 6mm. Their 2mm one is £15. These tools cut sideways as well as parting but the max parting depth is limited due to being double-ended. You can also get rounded "profiling" inserts and the inserts are available uncoated for aluminium machining.

Murray

[Chris Evans 6Participant @chrisevans6]

I think it is more to do with the condition of the lathe than the tool. I use a 2mm tipped blade from ARC on a home made rear tool post. It works very well up to 2" diameter EN1A and well on smaller tougher stuff. After that it is operator wimping out and sawing rather than risking scrapping the work !

[SteveIParticipant @stevei]

Posted by ega on 05/12/2017 18:31:51:

Posted by Neil Wyatt on 05/12/2017 18:09:20:

Greenwood have a new replacement for the Kit-Q-Cut coming soon, hopefully some news in the next MEW.

Neil

I shall read this with interest as I always thought the original design was rather basic. I hope the news will include information about the reasons for any changes.

That is interesting. I've been using the Greenwood Kit-Q-Cut for the last few years. It parts like a hot knife through butter, but I've worn it out, the holder is slightly bent and it no longer retains the tip.

Due to the high cost I've now switched to GFN inserts and regular SGFH blade and holder.

Steve

[richardandtracyParticipant @richardandtracy]

I bought an MGMN style toolholder + 4 double ended inserts for under £9 from e-bay seller cskwin2015. That was earlier this year. I have done a fair bit of parting with it (by my standards) and there have been a couple of times when I'd have expected my £9 HSS tool to shatter. No trouble from the MGMN tool even at 2mm wide on my Warco WMT300.

So, have to back Muzzer's assessment, worth getting, but with limitations and benefits.

Regards

Richard.

[Harry WilkesParticipant @harrywilkes58467]

I have one of the Eccentric Engineering parting-off tool mounted in the rear toolpost on my myford S7 best thing since sliced bread as far as I'm concerned ! Previously I was one of the guy's that struggled with part off but since fitting the Eccentric Engineering parting-off tool I don't have any problems.

H

[HopperParticipant @hopper]

Mate of mine bought a T shaped parting tool blade and holder from Eccentric. It has a strip of carbide along the top of the T. He uses it for putting circlip grooves in the outside diameter of hardened steel bearing races about 50mm diamter — in a mini lathe. Can't complain about that for performance.

[Nick HulmeParticipant @nickhulme30114]

For general parting and large work I use a Glanze holder with 3mm inserts in the front QCTP on my Super 7.
For plastics I use a HSS tool honed to a very fine edge.
For thin walled work I use a HSS tool with a slight angle on the tip to ensure a clean cut on the section parted off.
For Polyurethane and thin walled plastic work I use a Stanley Knife blade superglued to the free end of the Glanze holder in the rear QCTP.
For Brass and light batch jobs I have an inverted HSS blade holder for the rear QCTP

Having the blade vertical and parallel to the slide travel are both critical to a good parting experience, good spindle bearing adjustment is a big help too.

[egaParticipant @ega]

Posted by Hopper on 05/12/2017 23:08:34:

Mate of mine bought a T shaped parting tool blade and holder from Eccentric. It has a strip of carbide along the top of the T. He uses it for putting circlip grooves in the outside diameter of hardened steel bearing races about 50mm diamter — in a mini lathe. Can't complain about that for performance.

Hopper:

I couldn't find this interesting item on the EE website.

[John HaineParticipant @johnhaine32865]

I use 2. One is a Kit-Q-Cut from Greenwood bought a long time ago which is excellent (in a standard Dickson QC holder), I think I'm on my second insert. The other is a rear p/o tool I got from Kirjeng that takes Dickson-style QC holders, and I have one designed for a wide blade 2.5mm wide. I grind this with a hollow in the top surface (made with a diamond needle file) to curl the chips in (like the Kit_Q-Cut).

They both work very well, but I use the kitqcut usually since the rear toolpost gets in the way and I can just put it on the Dickson post when I want to part off.

[Neil WyattModerator @neilwyatt]

Posted by ega on 06/12/2017 10:15:09:

Posted by Hopper on 05/12/2017 23:08:34:

Mate of mine bought a T shaped parting tool blade and holder from Eccentric. It has a strip of carbide along the top of the T. He uses it for putting circlip grooves in the outside diameter of hardened steel bearing races about 50mm diamter — in a mini lathe. Can't complain about that for performance.

Hopper:

I couldn't find this interesting item on the EE website.

http://www.eccentricengineering.com.au/index.php?option=com_content&view=article&id=31&Itemid=45

[Mick B1Participant @mickb1]

Posted by Neil Wyatt on 06/12/2017 11:11:33:

Posted by ega on 06/12/2017 10:15:09:

Posted by Hopper on 05/12/2017 23:08:34:

Mate of mine bought a T shaped parting tool blade and holder from Eccentric. It has a strip of carbide along the top of the T. He uses it for putting circlip grooves in the outside diameter of hardened steel bearing races about 50mm diamter — in a mini lathe. Can't complain about that for performance.

Hopper:

I couldn't find this interesting item on the EE website.

http://www.eccentricengineering.com.au/index.php?option=com_content&view=article&id=31&Itemid=45

I don't think my HSS blade would have a prayer on hardened races, but that's rather an outlier of a requirement and I've certainly never needed to do anything like that.

Even the link admits in the notes at the end that conditions and techniques for parting can be highly idiosyncratic. That old cartoon set I keep seeing here and in magazines illustrates only the extremes of a multidirectional spectrum.

I think nothing is ever perfect in all conditions, and that there ain't no best parting tool.

[not done it yetParticipant @notdoneityet]

Mick,

I think you may have missed this bit:

It has a strip of carbide along the top of the T

[Mark P.Participant @markp]

I’ve been using a T shaped parting blade from Chronos, made my own holder myself, best parting blade I’ve ever had!
Mark P.

[Mick B1Participant @mickb1]

Posted by not done it yet on 06/12/2017 11:38:54:

Mick,

I think you may have missed this bit:

It has a strip of carbide along the top of the T

Nah, saw that 😀 – and I'm sure it's good if you're trying to cut hardened stuff, but that doesn't necessarily make it the answer to every issue.

[Author]

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