Carbide insert source

[Tony Ennis]

I'm looking for higher quality carbide inserts so I can see if they are better than the generic ones that came with my tooling. I'm using TCMT32.5x inserts. What 'x' (radii) are recommended for your weekend warrior with a not-too-powerful lathe? My assumption is that a tip with a larger radius will create a better finish.

Of course I'm looking for the sweet spot between price and quality.

Do we have favored brands of inserts and favored distributors?

[lakeside53]

A larger radius will only create a better finish if you have sufficient rigidity and can take the minimum required DOC.

On those small inserts, I'd use a 1, maybe a 2.

I like kennametal, sandvik, mitsubishi or most major brands... Ebay can be your friend if you are able to decode the iso or ansi part numbers. There are many variations available... Buy a few types and match them to your needs.

[Black Forest]

Hello Tony,

I am very new to using machine tools. I am now studying the huge books that my distributor sent me for Walter tools and inserts. I might be wrong but I think Walter owns Sandvik and a couple other major tool suppliers.

This is what I have found out so far. Quality tooling saves you money and headaches.

Before I was not sure if it was me, the tooling, the machine. So I bought good machines and then quality tooling from Walter. Now I am the limiting factor. It just seems easier to learn how to do things correctly and with better results if I use high quality tooling. Learning curve is greatly shortened I think if you use good tooling.

Just my .02cents and probably not worth much more than two cents.

[Arthur.Marks]

One suggestion is to get a couple different grades from McMaster: http://www.mcmaster.com/#catalog/117/2504/=ewk5jr They will all be top brands but not necessarily the same brand. It will provide a point of comparison, though, and give you experience with different coatings. After that, you will have a better idea which grades/coatings make a difference for you and what spec's are worth noting when buying elsewhere.

[RWO]

The grade and coatings are of no real consequence for the home shopper. They only become important when the insert is used in a machine that can run it at or near it's physical limits continuosly ( unlikely in a home shop).

I have found some good deals here: http://www.carbidedepot.com/

RWO

[KiddZimaHater]

I've found good deals for Sandvik inserts on Ebay.
(*WARNING* - Here come the Ebay haters)

[beanbag]

It's not so much about generic vs brand name, but more about finding the right geometry and edge prep for your application. For example, you can get a very expensive insert from Kennametal, but if it is a roughing insert designed for a big CNC lathe, then I am pretty sure you are going to get poor results on your dinky lathe.

In general for a home shop, the type of insert I would recommend has these characteristics:

Ground edge. The third letter in the designation is a "G". They typically means the edge is sharper, for freer cuts and better surface finish on finish passes.

Positive rake chipbreaker. Results in lower cutting forces.

The right coating and grade for your application. The grade ranges from brittle (best wear resistance) to tough (for non-optimal cutting conditions). Choose a tougher grade if possible.

You might start off with three different types:
1) Specifically designed for aluminum. The manufacturer will usually point this out. Usually (but not always) uncoated, with high positive rake. This is an easy insert to find, whether brand name or generic. Very sharp edge (can cut your finger). Try to choose a tougher grade if it is an option.

2) For steels. I would still choose a high-ish positive rake if possible. Some manufacturers make these with as high of a chipbreaker as the aluminum version, but in a tougher grade and a ferrous-compatible coating. A good example of this is the Kennametal HP chipbreakers, grade KC730.

3) A sacrificial insert for hogging nasty steels. In this case, a tough grade, less positive chipbreaker. You don't want super sharp edge, but still somewhat sharp because your lathe is still dinky. A good example of this is the Kennametal LF chipbreaker. LF means "light finishing" for an industrial lathe, but for you, that means "roughing". Whatever generic insert you have, with the third letter being a "M", will probably work ok in this application.

[Carld]

beanbag has some good points Tony. Get a copy of the MSC catalog because it has a large section devoted to different manufacturers inserts. The Enco catalog has a good selection also. Use it for price comps. Call or email the manufacturers and ask what they recommend for what ever your machining. Some of them are very helpful. You will have to make up a business name to get them to talk to you.

I called them when I was looking for inserts to turn Monel and Hastelloy.

[wierdscience]

+1 for Mcmaster,not the biggest selection,but you can buy just one insert if you want.

[PixMan]

For home shop use on low-power lathes, I'd rate the selection of insert top form geometry (chipbreaker) as 80% of the solution, grade & coating at 20%.

In a TCMT32.5x size, look for TCGT32.51 or TCGT32.50.5 or TCGT32.50. Always try to have your depth-of-cut (per side) be equal-to or greater-than the tool nose radius, and match the feed per rev to the recommendation for the chipbreaker. If you can't find that info, simply look for chips being under control.

One Ebay seller I have gotten the very best deals from is dans_discount_tools. Where some sellers on Ebay sell one at a time for ridiculous prices, Dan sells new packs of 10 for as little as $35 (US) for top-quality name-brand inserts.

BF - Sandvik AB owns Sandvik Coromant, Walter, Precision Twist Drill, and a few other tooling companies, in addition to their mining, steels, medical and other industrial businesses.