PDA

View Full Version : Say'n Hi: Grinding wheels and reamers.



Ray C
12-06-2010, 10:57 PM
Hi. I've been lurking for a few days and decided to post... I'm a shop hobbyist but was a certified mechanic in the late 70's. Now I've rekindled general machine-shop work with lathes, welding etc. I used to rebuild antique flywheel diesels and lately have been rebuilding modern diesels and making generator sets in the 20-30kw power range. It's all fun and a distraction from the real day job. Interested now in focusing on machinst-like actvities and that brought me here. FWIW, my father and most of my close relatives were old-school tool & die makers. I recently reburbished an Atlas lathe -and wish I had the old Leblond that I used as a kid. Ok, intro over.

So, I use mostly HSS lathe tool bits but have the occasional need for carbide tips. AO wheels run away in fear of carbide and am wondering how well green wheels hold up and if the green wheels work well on HSS (seems they should). What grit are people using? If diamond wheels are the way to go, how long do they last and how should they be cared for? Does diamond come in different grits?

Also, for non-precision work, I've been thinking about a set of adjustable reamers. They have their obvious limitations but am wondering if they hold up and if the adjustment remains set while using them.

Thanks -and if anyone ever wants to chat about generators and engine matching, just hollar...

AllThumbz
12-06-2010, 11:28 PM
I'm a newbie who just picked up a Baldor with two green wheels and was advised by the knowledgeable around here to toss the green wheels for both carbide and HSS and buy an aluminum oxide (white) wheel for HSS and a diamond wheel with a diamond dresser for carbide. Hope that helps a bit.

deltaenterprizes
12-07-2010, 12:07 AM
Welcome to the forum, ditto the above post.

wooleybooger
12-07-2010, 12:11 AM
the gray wheels that come with most grinders barely make a spark on carbide. the green wheels cut carbide really good but wear fast. mild steel with a green wheel will cover your hand with dust in no time. white wheels work very good on HSS toolbits and drills. diamond is probably best but i havent found an affordable one that fits my 5/8" shaft grinder. who knew grinding was so complicated?

J. Randall
12-07-2010, 12:14 AM
Ray, diamond wheels are great for finish sharpening, but a good one is expensive. If you are just going to dink about a little with carbide, don't discount a green wheel, especially if you need to rough grind or shape carbide. You can finish up with a diamond lap or sharpening stone and have a good edge. You can grind hss on a green wheel, but it is not as good a choice as aluminum oxide.
James

SGW
12-07-2010, 10:24 AM
I use green wheels for everything. They wear fast and throw grit, but when grinding HSS steel they heat up the steel much less, cut HSS well, and they can grind carbide. I use them because I have one grinder I have to use for everything.

That being said, they're a compromise. There are better wheels for grinding HSS, and a diamond wheel does a better job on carbide. Diamond actually cuts carbide, while a green wheel just sort of breaks it off.

Ray C
12-07-2010, 02:10 PM
Thanks folks for the grinding wheel tips. I don't use (much less sharpen) carbide very often at all so I'll stick with AO and maybe try a green wheel some day.

AllThumbz
12-07-2010, 02:18 PM
No problem, Ray. I'm learning in this area myself, so any good information I get, I am glad to pass on to you. I have been accumulating good sources on how to grind HSS tools so that I can attempt it myself when my grinder arrives.

lazlo
12-07-2010, 04:52 PM
I'm a newbie who just picked up a Baldor with two green wheels and was advised by the knowledgeable around here to toss the green wheels for both carbide and HSS

In that thread, several posters were suggesting that you should throw out the green concrete wheels that come on the Harbor Freight grinder.

Real green silicon carbide wheels are decent -- they don't leave a great finish but I've often seen them in pro shops.