Insert size

Having just received a 9 piece set from Warco I have been looking around the site and mostly understand what the letters are when purchasing replacement cutters. But one thing that I seem to miss is the size of the cutters.

Quite often I see mentioned the size of cutting edge how is this measured.

I know that many will state that don't buy in sets but as these were supplied FOC along with a HSS set because of the amount I brought I can't complain.

Are they all different types?

Derek

Along the cutting edge but with the adjacent sides extended to ignore the radius at each end.

Emgee

It is THIS set so different cutters.

Is that along a complete edge or is it only half of the edge from the centre to the tip ignoring the radius

A lot of the time they are sized according to a circle that will fit within the three or 4 sides for example a CCMT 06.... will have a 6mm dia inscribed circle

EDIT if you go to page 390 of this virtual catalogue you will see where all the different shapes are shown they all have the circle in them, if you then go to the chart for sizes you will see listed under "IC" inscribed circle the size of the inserts, seldom done by measuring the sides.

Edited By JasonB on 11/11/2021 16:17:25

I've got the same set I think. It's best for heavy cutting rather than fine work. The inserts and holders work best on a powerful, stiff machine. 5HP wouldn't phase them!

Generally, carbide inserts are shaped to cut on all the available edges. This is unlike HSS, which have to be ground to make an edge. Edges are unlikely to be used along their full length because Inserts are limited by other factors.

Your square inserts cut at the point and could cut all along each edge except the tool gets in the way and/or the lathe doesn't have enough power and rigidity to take a cut that deep. In practice cutting is limited to a few millimetres each side of the point; I rarely take cuts more than 2mm deep. Excellent roughing tool and it does chamfers and plunge Vs.

The straight triangular inserts can cut along the entire edge, which is occasionally useful. Otherwise it's a good roughing tool, but I wouldn't normally use the whole cutting edge to take deep cuts. (You can - experiment if it seems useful!)

The triangular inserts with a bump in the middle cut at the point and on the straight bit. I find this shape most useful because it cuts well and can get into corners to make a nice right angle.

No round insert in the set unfortunately. They're used for forming, but the entire edge of a round insert will cut. If the edge is chipped, the insert can be rotated slightly to present fresh edge. Likewise square inserts can be rotated 4 times to present a new point and edge, triangular types 3 times.

For fine work, I go down a holder size and use smaller inserts, especially the sharp non-ferrous types, which I cheerfully use on steel. Just be careful not to bump the points.

Dave

For those that don't think an insert size can be quoted by the length of the cutting edge I suggest you go to the following link, explains the nomenclature of inserts,

**LINK**

Go to this link for threading inserts

http://www.helmancnc.com/threading-insert-nomenclature-for-cnc-dummies/

Emgee

Edited By Emgee on 11/11/2021 18:15:56

Thank you everyone I now have worked out most of the information I need.

Jason that is the page I have already saved and was working by just could not see for looking about the right sizes

Slight error on my earlier post, an 06 insert has a 6.35IC not a 6mm one

in most cases these code numbers bear little resemblance to the actual edge length (triangles are close) as a quick sketch will show.

On the left a typical C shaped insert eg CCMT size 06 and on the right a typical D shaped inset eg DCMT size 07, both have an IC of 6.53 but the edge length is neither 6mm or 6.35mm so best way to see what you have is to hold a bit of rod or a drill shank of the right IC ontop of the insert and see how it fits. On 4 sided inserts you can measure between two opposite parallel faces which will also give the IC. Click for larger image

Edited By JasonB on 11/11/2021 18:52:08

Edited By JasonB on 11/11/2021 18:56:04

To further explain Sanvik inserts information below, it is easier to see on the 35 deg VC type it is LE+RE, so is the projected length of the cutting edge from the centre of the insert to the tip.
Although the IC of the enclosed circle is mentioned no dimension is given so doesn't assist in identifying the insert size.

Emgee

IC size for common shapes and size codes here

Emgee that does seem a difficult way to determine the size of an insert particularly for the beginner and even more so as they are unlikely to know the tip radius so won't know what to add to the lengths.

This is the simple way based on IC size:

I've added a tip radius of 0.2 to that D shaped insert and highlighted the 6.35mm IC (1/4inch) I have also highlighted the two easy options to measure distance between opposite faces and highlighted those also at 6.35mm which can easily be measured with digital callipers.

Note there will be a tolerance of this size so could be 0.15mm difference but as the common IC sizes jump by 3.175mm (1/8inch) should be easy enough to tell which IC you have.

All you then have to do is pick a chart both the MSC virtual catalogue I posted earlier or the Mitsubishi link in the post above will do. Along the top pick the shape code that you have already identified in stage 1 and then come across for the IC size just measured and that will give you the size code (not actual size)

Derek, there is also another way to identify your inserts. Provided the holders have the code engraved on the side you will be able to tell shape and size of insert from that, about page 430 of the MSC catalogue they show how to work it out, 2nd letter is insert shape, last pair of numbers is IC size code.

Thank you Jason I will look when I go out to the workshop to see what is on the holder