Thread: 12 mm / 1/2 inch HSS Tools

I am happily getting a new lathe (1970s vintage) into operation and it is fitted with a Dickson style QCTP allowing tools to 16 mm.

I tried today grinding a 1/2 inch tool as a standard right hand knife tool - what a pain.

Previously I have used 5/16 inch in my home-brew QCTP, 1/4 inch in original US style lantern post holders and a Diamond Tool holder.

Is the pain of grinding 12 mm / 1/2 inch HSS tools worth it ?

My first reaction is to use my stock ( 8 bits) of 1/2 inch HSS as packing/parallels and get on with making holders for 1/4 inch and 5/16 inch HSS.

Happy machining,
John.

Using 1/2" HSS is not worth the effort. Definitely use HSS but use the 1/4" square sticks. They are far cheaper to buy and so much easier and quicker to grind to shape. Make a toolholder for the 1/4" HSS and you will never look back. I have a toolholder that I made for 3/16th HSS and I use it at least 99% of the time. I have some 5/16th and 3/8" HSS that I use to make solid boring bars with for holes up to 1 1/2" deep. I have heard that the diamond toolholder is not really all that good so I have never bought one. A toolholder can be made on the lathe for 3/16th HSS and is a great project to start with. If you want a drawing of my 3/16th toolholder, I can send it to you as a PDF file. A 3" length of 3/16th HSS costs around $7.00. It lasts for yonks and is great to use, I can also take 3mm deep cuts with it. What does a stick of 1/2" HSS cost you?

Kody

Just use whatever you have handy, pack it up to centre height and away you go, buy the 1/4 inch , it's LOTS cheaper.

Kody, think you better do a bit more research on the tangential toolholder before making statements like that !

Regards radish

[QUOTE=Kody;1034751 What does a stick of 1/2" HSS cost you?

Kody[/QUOTE]

god i paid $30 for a single stick and got 4 far out i wish i hadn't now

Originally Posted by new_guy90

god i paid $30 for a single stick and got 4 far out i wish i hadn't now

I've never had to buy any HSS tool steel
My employers have been generous over the years ,I have a draw in my machinists box full of HSS bits from 1/8" up to 3/4" square and round.

I've got four pieces of 1/2"x 6" round I use as parallel bars on the mill .


Kev

Just out of curiosity,,,have you never tried ebay for your HSS tooling needs? Search "Cleveland Mo-Max" and you'll find something from the US. I bought 50 sticks of 1/2" X 4" cobalt hss for an average of $2.00/stick including shipping. That was an unreal deal, but good deals are still to be had frequently.

Often 1/4" bits go for cheap money-great for traditional or tangential holders.

Greg

Thanks guys for the comments - as I thought, the 12 mm (1/2 in) HSS is not worth the pain.

I have made several holders for 5/16 in HSS as that is the standard size used at the TAFE in their machining classes.

The Diamond Tool works fine as a general purpose metal remover and gives an immaculate finish if it is 'shaved' along on the final cut.
The real bonus is the instant height adjustment, ease of grinding and even easy to hone in place on the lathe.

Happy machining,
John.

Originally Posted by radish

Just use whatever you have handy, pack it up to centre height and away you go, buy the 1/4 inch , it's LOTS cheaper.

Kody, think you better do a bit more research on the tangential toolholder before making statements like that !

Regards radish

I agree with radish. I have seen the diamomnd tool in use on smaller lathes and it seems to work well . I just finnished making a tangential tool block for a friend . He likes it for the ease of tool bit grinding and it is a more rigid setup than the diamond .
Its like any other tool it has its limits and when its not suitable you change to something else for that job.

Originally Posted by electrosteam

Thanks guys for the comments - as I thought, the 12 mm (1/2 in) HSS is not worth the pain.

I have made several holders for 5/16 in HSS as that is the standard size used at the TAFE in their machining classes.

The Diamond Tool works fine as a general purpose metal remover and gives an immaculate finish if it is 'shaved' along on the final cut.
The real bonus is the instant height adjustment, ease of grinding and even easy to hone in place on the lathe.

Happy machining,
John.

I think the 1/2 inch HSS is better kept for a form tool rather than grinding down to normal turning points . 1/4 x 1/4 is cheaper and easier to buy 3/16 is practical in a small lathe also. 1/8 is just too hard to hold and grind for me anyway.