making square groove on end of round bar

[littlerickParticipant @littlerick]

I need to make a square cut groove that is around 8-10mm deep on the flat edge of a round bar. Like a "O" but i need 3 of them getting smaller.

I thought a parting tool would be best, but now I have snapped to of them, i'm thinking maybe not!

Work piece is an old large steel bolt head approx 41mm now its rounded off,

Any tool that is deep enough to cut, while being small enough not to jam and snap as the cut gets deeper.

Rick

[littlerickParticipant @littlerick]

[BazyleParticipant @bazyle]

Hacksaw. Several blades to make wider cut.

[KWILParticipant @kwil]

How wide is this groove and what kind of parting tool are you trying to use? An drawing would help.

[Ady1Participant @ady1]

Stiffness is everything with parting off type operations and try to cut from the back with an upside down tool to help with dig-in problems

Using the backgear can also make things a lot easier

[jason udallParticipant @jasonudall57142]

sounds more like treppanning than groving…this is a face operation.

what radi? you will probably need one tool for each radi..

hole saw?

 

and how many?

a home made cutter or cutters might work..turn/bore saw/file  harden..

 

Edited By jason udall on 23/09/2013 11:45:42

[Sub MandrelParticipant @submandrel]

Your bolt head will be tougheend. If the job isn't critical, anneal it by heating to a good red heat and cooling slowly.

Take a piece of HSS of the same diameter as your groove's width, make a holder for it and grind the tip away to half thickness for about 1/2 of a diameter distance. provide a few degrees of relief at the end of the cutter and just a smidgin of top rake (only a little so it doesn't dig).

The shape won't jam at the sides, even in small diameter grooves but you will need to go slowly.

It works, I've used one to groove the side of a laser cut flywheel in medium steel.

Neil

[JasonBModerator @jasonb]

At that depth and width you may want something more rigid in which case grind something like this from a 10mm HSS blank

[jason udallParticipant @jasonudall57142]

NEIL nice

'course I hadnt thought that ….

most I have used have been insert holders..with large ( about 45degree worth) keel for support ..which is what brought the hole saw to mind

[littlerickParticipant @littlerick]

sweet thanks… i'll try a few ideas n see what works out.

[NobbyParticipant @nobby]

Support with a centre from the tailstock if you can
Nobby

[Grizzly bearParticipant @grizzlybear]

Hi littlerick,

A picture would be nice. Confused .com

Regards, Bear..

[JasonBModerator @jasonb]

Sounds like this is whats wanted

[littlerickParticipant @littlerick]

yes thats exactly what i need… im going to get some tool steel and have a go at making a tool for the job.. main problem is getting it strong enough while at the same time shallow enough not to jam on sides..

[Grizzly bearParticipant @grizzlybear]

Thank you JasonB for the picture, Impressive. We just need to know what its for. Branding mice perhaps.

Regards, Bear..

[magpieParticipant @magpie]

41mm bolt head, will have to be BIG mice !!!!!

Cheers Derek.

[mark mcParticipant @markmc72333]

What about putting it in a rotary table and mill it out?

[littlerickParticipant @littlerick]

No rotary table yet… in fact tools are limited which is 80% of problem.

[JasonBModerator @jasonb]

Although these show the middle being trepanned out of a plate the tool is similar to what I sketched above except for the rounded end as that was left over from a previous use.

This is 5/8" (16mm) brass cut 8mm from either side

And this is 10mm steel cut just short of 5mm each side then hit it with a hammer and the middle drops out safely.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by littlerick on 24/09/2013 07:33:39:

No rotary table yet… in fact tools are limited which is 80% of problem.

.

Clearly then, the suggestions by JasonB et al are the way to go … But, for the future, you might consider buying/making a Milling Spindle on a Vertical Slide for your Lathe.

MichaelG.

[jonathan heppelParticipant @jonathanheppel43280]

I second the inverted tool suggestion. Also if you're feeding with the topslide, make sure it's adjusted well, including backlash on the screw if fitted, because self feeding is more of an issue when trepanning. Easy on rake angle too for the same reason.

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