Technical Information

Surface Finish (cont’d.)

Figures 6 and 7 compare the feed marks produced with a noseradius insert to those produced with a wiper insert. A wiper insert with a large radius for wiping out or reducing peaks (figure 7) has been effective in producing finishes below 3.2 (100) Ra. Figures 6 and 7 show the wiper insert is designed to “top off” the peaks of the feed marks. An improved surface finish, surface flatness, and reduced taper will result.Wiper inserts are normally set at .001 to .0015 in (0,025-0,04 mm)above the highest positioned insert in the cutter to ensure a good wiping action. Kennametal wiper inserts are typically designed to fitinto any pocket in the cutter body. This means one or more wiperinserts can be used. Interchangeable wipers can be used to share the load on the periphery of the cut in feed per tooth. Poor Surface Finish cause solutioncutter runoutCheck for high insert, dirt in thepockets, or dirty spindle and cutter mounting face. Also, look for burrs onthe cutter and damaged cutter pocket.worn or chipped insertIndex insert.feed per revolutionexceeding flat on wiperReduce feed rate or installwiper with greater effective insert facet width.wiper insert is set toohighSet the wiper insert .001 to .0015 in(0,025 to 0,04 mm) above highestinsert.chatterCheck rigidity of machine andtable fixturing. Check arbor and spindle, adjust feed rates, adjustrpm, or reduce cut width. Considercutter with fewer pockets.

highRafeed markpeak lowRapeakfeed mark

A BFigure 7: Feed marks produced with a nose radius insert (A) compared tomarks produced with a wiper insert (B).

Figure 6: Peaks produced with a standard radii insert (top) compared tothose produced with a large radius wiper insert (bottom). feed marks feed marks

To place an order, contact Kennametal or your authorized Kennametal distributor, or visit www.kennametal.com.499