14.5mm end mill equivalent

Thanks for all your replies. After much thought, I am going to drill 6, 8, 10mm then use a boring bar to size - the posts about the parts grabbing the slot drill/end mill worried me a little!

appreciate all your input everyone.

thanks Ramon for the pic of the old slot drill bore. I am not confident enough yet to make one of those!

For a small number and if the tolerance wasn't too tight I'd grind a drill to have a flat end. It doesn't have to cut to the centre as there is a 9mm hole right through if I've understood it, so drill 9/16 to nearly full depth then bottom it with a flat end drill. Of course this means having a spare 9/16 drill, or a lot of drill grinding. Alternative is to make a D bit, but I've never used one in steel at that diameter, so I'll leave others to advise.

Bill, It's held in a Myford QC holder for boring tools - the type that has a vee groove machined in the lower face.

Margaret - Good luck with your task If you can learn how to use an off hand grinder to shape HSS then you will have a huge 'extra' to call on in future. Just bear in mind you won't necessarily get it right at first but keep trying and you will. Also bear in mind it's only the very tip of the tool doing the cutting that has to be right - what's to the side and behind it is just support

Best - Tug

I don't buy ready ground HSS tooling, just blanks, so can't post a link. What I have done over the years is beg, buy or liberate boxes of used HSS tooling. So when looking for a specific tool there is often something fairly close that I can adapt on the bench grinder. A quick look in the pile of HSS by the lathe found this, which will do the job:

I'm not sure what material you are machining, is it brass? If so then the tool can be even simpler, just grind a radius that is equal to 1/4" on the bottom corner of a 1/4" square HSS blank, square off the end and that will do the job. No top rake is needed for brass.

Andrew

Thanks everyone-

Andrew - I don’t yet have the expertise to grind anything but it’s something I can learn for sure. Certainly be more cost effective I guess than buying new tools. Yes it is brass - I have taken Jason’s suggestion and purchased the boring tool and tip - I’ll do it that way for now until I learn about the grinding skills.

Ramon - thank you. I have no idea what a off hand grinder is? But it sounds scarey and fun and likely to damage my nail varnish! 🤪

Duncan - that sounds like a very logical and good method but I am not yet confident enough to make my own tools nor do I have stock of soare drills etc.

thank you eveyone

Margaret

If you are setting out using a lathe an offhand bench grinder is more ore less mandatory unless you constantly want to buy ready made tooling.

Lot's to choose from but heres one from Axminster Tools as an example - it would not take the cost of many inserts to pay for one

A noisy geared Black and Decker 5" version was the first accessory I bought with my first lathe. It was soon replaced with a small, much less noisy, 'Slibette 5" that I still use virtually on a daily basis.

Enjoy your adventure with machining wherever it takes you - it's a great pastime

Ah, ok, I see what one is now. Thank you Ramon.

and thank you for your kind wishes - I am having a great time learning new things every day from

people like you and all the kind contributors to my posts. Having a resource like this is invaluable.

take care

Margaret