- Joined
- Jun 23, 2011
- Messages
- 786
I've heard it said on this forum that carbide inserts don't have much use in the home shop. Now I'm not so sure.... Generally they are pricey - maybe as much as $12 each! But, they have advantages too. No stopping to resharpen - just reindex or replace the insert and pick up where you left off. And you don't have to waste time setting the bit height. Once is it.
If you're not an expert HSS grinder or get inconsistent sharpening results, maybe inserts are worth looking into... We never seem to have enough time in the shop, so cost effective time savers, to me, are invaluable. Heck, I even get a break on cleanup... These carbides last long and cut well dry. So, no oil to clean up..
What if I told you you can get carbide inserts that work well on a variety of materials and offer three cutting points per insert for about $1.70 each? It's true. Each insert is about the same price as a 1/4" HSS blank. Granted you can get more than three sharpenings from an HSS blank, but I'd rather make something than sharpen cutters (but I enjoy that too). Of course, surface finish from HSS can't be beat by carbide, but modern inserts are very close.
Here's the story... When I bought my used lathe, it came with a box of 3/8 inscribed circle, triangular inserts with a TiN coating and no insert holders. The box was marked TT-321. Certainly not the ISO insert code... What are they?
Since I'm not using them for CNC, I went ahead and made a few insert holders for these inserts. I think I posted how I did it a while back. It should be self explanitory when the inserts are in hand to make your own set. I found 6-32 switch plate screws fit the insert recess perfectly.
In any case, I've been hooked ever since and needed to finally buy more. A search on eBay resulted in several results for "TT-321". I bought a box of 10 for the paltry sum of $16.60 (for less than $6 more you can get them with TiN coating which seems to give a slightly better finish) to see how they performed. Well, the long and short of it is that they worked great! They're durable, give an excellent surface finish on brass, steel, stainless, aluminum, etc. I even take 0.100 DOC cuts with 'em in 303 stainless and they hold up. They compare favorably to the Iscar, Valenite, Sandvik, etc inserts I've borrowed from work as a comparo.
In fact, the flywheels for the SOSE build were cut using these and I got several favorable comments about the surface finish. I've now bought two more boxes. They're made (country of origin not marked) by Cobra Carbide, although the eBay listing doesn't show the manufacturer...
Here're links to the "buy it now" pages for both Tin coated and C2 inserts:
http://www.ebay.com/itm/NEW-10PCS-T...312?pt=LH_DefaultDomain_0&hash=item3cc3f22dc8
http://www.ebay.com/itm/NEW-10PCS-T...394?pt=LH_DefaultDomain_0&hash=item3a72f19232
I hope I'm not violating any policies here by posting links and I have no other relationship with the seller than as a satisfied customer. I just want to share with the gang...
John
If you're not an expert HSS grinder or get inconsistent sharpening results, maybe inserts are worth looking into... We never seem to have enough time in the shop, so cost effective time savers, to me, are invaluable. Heck, I even get a break on cleanup... These carbides last long and cut well dry. So, no oil to clean up..
What if I told you you can get carbide inserts that work well on a variety of materials and offer three cutting points per insert for about $1.70 each? It's true. Each insert is about the same price as a 1/4" HSS blank. Granted you can get more than three sharpenings from an HSS blank, but I'd rather make something than sharpen cutters (but I enjoy that too). Of course, surface finish from HSS can't be beat by carbide, but modern inserts are very close.
Here's the story... When I bought my used lathe, it came with a box of 3/8 inscribed circle, triangular inserts with a TiN coating and no insert holders. The box was marked TT-321. Certainly not the ISO insert code... What are they?
Since I'm not using them for CNC, I went ahead and made a few insert holders for these inserts. I think I posted how I did it a while back. It should be self explanitory when the inserts are in hand to make your own set. I found 6-32 switch plate screws fit the insert recess perfectly.
In any case, I've been hooked ever since and needed to finally buy more. A search on eBay resulted in several results for "TT-321". I bought a box of 10 for the paltry sum of $16.60 (for less than $6 more you can get them with TiN coating which seems to give a slightly better finish) to see how they performed. Well, the long and short of it is that they worked great! They're durable, give an excellent surface finish on brass, steel, stainless, aluminum, etc. I even take 0.100 DOC cuts with 'em in 303 stainless and they hold up. They compare favorably to the Iscar, Valenite, Sandvik, etc inserts I've borrowed from work as a comparo.
In fact, the flywheels for the SOSE build were cut using these and I got several favorable comments about the surface finish. I've now bought two more boxes. They're made (country of origin not marked) by Cobra Carbide, although the eBay listing doesn't show the manufacturer...
Here're links to the "buy it now" pages for both Tin coated and C2 inserts:
http://www.ebay.com/itm/NEW-10PCS-T...312?pt=LH_DefaultDomain_0&hash=item3cc3f22dc8
http://www.ebay.com/itm/NEW-10PCS-T...394?pt=LH_DefaultDomain_0&hash=item3a72f19232
I hope I'm not violating any policies here by posting links and I have no other relationship with the seller than as a satisfied customer. I just want to share with the gang...
John
