Some comments about Harbor Freight diamond cutting discs and a question

[ericc]

I've used those little HF diamond wheels alot. Mostly for sharpening/ touching up carbide inserts and brazed carbide lathe tools, but I used one to neck down a long read 1/2" carbide end mill the other day. Not by much, a few thou at most, but it worked just fine. I tend to use the face the most. I have a feeling that the thin edge wouldn't work for all that long as there's not a very thick coating of diamond on these.

That sounds like you got some pretty good life out of them. I am a little disappointed about the little use I got out of mine. It was good for only one use shaping a small (<3/8") boring bar with a brazed insert. The diamonds on the face are pretty weak, being only cosmetic, but they are real diamonds. They will polish an insert so it can be brazed, but that's about it.

Perhaps there is variation between lots. I got what I paid for. It said that I could return them for a refund if it was within 90 days. Too late. They sure were cheap.

 

[hman]

The Harbor Freight diamond wheels are rather coarse. Here's a 3000 grit diamond wheel that could be used instead:

https://www.amazon.com/dp/B071JVRYH9/?coliid=I1HGZWYUFT2F4&colid=2724NW8SCW7BT&ref_=list_c_wl_lv_ov_lig_dp_it&th=1

AFAIK, diamond wheels like to be run with some kind of coolant. The yellow tray under the wheel of my grinder is designed to catch any excessive drippage, and funnel it to the spout for collection.