Grinding wheels for HSS lathe tool tips .. advice wanted please.

[DAPPH]

I've spent a while in some supposedly good tool shops of late asking what grinding wheels they had for me to rough and fine grind 1/2 " square HSS. to make cutters for my lathe.
All I managed to get was blank looks from all the staff and a pointing finger indicating me to look at a cheap & nasty 6 " wheeled made in China or India blue double wheeled electric grindstone machine .

It's donkeys years since I purchased a replacement wheel and even longer for the slips & hones needed to fine shape the ground tip.

Would some of you guys who are in the know, please tell me how the stones and slips are graded , what sort of stone & slip materials are available for the task and finally where I can get them from.
I'm loathe to eBuy any without knowing some specifications , terminology & such stuff .

 

[doubleboost]

Norton are good wheels
Aluminium oxide
Silicon carbide
Medium grit
For tip tools you need a "green " wheel

 

[DAPPH]

Do the wheels have a grit /abrasiveness number ?

 

[hotrodder]

There are different colours of aluminium oxide wheel which are slightly different... grey is the cheap/general purpose, white = premium Al oxide which is cooler cutting as they're very 'friable' so break down exposing fresh grit more readily. The downside of that is more rapid wear. Red/pink = white Al oxide with a dash of chromium oxide to make 'em tougher i.e. they cut quickly and run cooler than grey while lasting longer than white. Blue are better again variously described as microcrystaline/ceramic etc or 'propriatary' as with say Norton 3X stones

Proper abrasive suppliers typically have things like this http://www.midlandabrasives.com/cat_name/grinding-wheels.aspx to translate how they're sold- hardness, grits etc

 

[RonA]

I bought a green stone to re-edge my tungsten carbide tipped lathe tools. As they say it does exactly what it says on the tin. It does a pretty good job on HSS tools when preparing the tools for screw cutting.
A diamond tipped dressing tool is a must have accessory when finishing grinding one cutting tool & starting the next.
RonA

 

[Rig Pig]

Have a look on the J&L website, they are an industrial supplier instead of a DIY shop with a decent range of real kit. don't forget to check the speed your machine runs at.

Are the wheels on your grinder up to the job? If so then look on the side of the wheels it will tell you what the abrasive material is and what the bond is, the grit particle size, the speed rating and the original size. For normal offhand grinding of tool steel aluminium oxide or silicon carbide will do nicely, a course wheel for rapid shaping on one side maybe 36 grit and a fine wheel the other side for sharpening maybe 80 grit.

There will be loads of information on the internet if you do a search.

 

[Pete.]

For basic shaping I use a 5" grinder and 1mm disc. Nothing beats that for getting yout initial angles in just clamp the tool in yuor vice and cut the required angles. After that I use an open white Al-ox wheel on my 8" grinder to rough in and a harder one on my 6" wheel if I need a good edge. I use a diamond wheel for carbide tools for a great finish and sharp edge.

 

[oilyneil]

Just started going back to HSS for some of my jobs,,so did some research and found this;
http://www.chaski.org/homemachinist/viewtopic.php?f=44&t=75985
I changed my wheel to an 80 grit white norton,,much nicer finish than the generic gravel on a wheel you get with a standard wheel,,,

 

[brightspark]

i sharpen my hss lathe tools on a disk sander .u can set the angle to whatever u want and use whatever grit disks to suit . then a quick rub up on an arkansas oilstone http://www.hallsharpstones.com/faq#how

 

[DAPPH]

Thanks guys you have given me enough details for me to go ahead ... Were do I get my £ 65 pocket money now that I'm being hung out by EON for about £4.5 k of damage to electrical goods & for reinstatement to the original standard ( from the power failure we suffered in the middle of last month ) ?