Single-point tools for turning the austenitic chromium-nickel grades
 must have adequate clearance to avoid work hardening of freshly cut
 surfaces.  The back rake angle should be as large as permissible, to 
 aid in breaking of chips.  Chip breakers are helpful, but their design 
 must be such that the cutting edges will not be weakened.  Improperly 
 designed chip curlers can cause chip crowding and tool damage.  
                                                                            
In this table, the design of single-point tools (made of high speed 
 steel, cast alloy and carbide) for turning stainless steels is compared 
 with designs for turning plain carbon, alloy and ultra-high-strength 
 steels.

The use of a cutting fluid is more desirable for machining stainless
 steels than for machining carbon or alloy steels for two reasons:  
 (a) stainless steels are generally less machinable than carbon or alloy
     steels, and 
 (b) the lower heat conductivity of stainless steels increases the 
     need for cooling.

Water-soluble oils (usually in proportions of 1 part oil to 12 to 20
 parts water) and sulfochlorinated cutting oils (having a viscosity of 
 300 SUS maximum at 100 F) are the cutting fluids most widely used in 
 machining stainless steels.
=========================================================================

             Nominal Speeds and Feeds for Turning Stainless Steels
                        With Single-Point and Box Tools

                               Rough turning (c)       Finish turning(d)
                                (.150-in. depth)        (.025-in. depth)

                                 Speed (sfm) of:          Speed (sfm) of:

Type of   Condi-    Brinell     HSS    Carbide tools   HSS   Carbide t'ls
steel     tion(b)   hardness   tools  Brazed  Dispos. tools   Braz. Disp. 

FM Fer    Ann        135 to 185   150     500    575    170     560    640
FM Mar    Ann        135 to 185   150     500    575    170     560    640
          Ann or CD  185 to 240   140     450    515    160     500    575
          Q & T      275 to 325    70     325    375     80     375    425
          Q & T (e)  375 to 425    40     150    170     50     200    225
FM Aus    Ann        135 to 185    95     400    460    115     450    515
          CD         225 to 275    90     350    400    110     400    460
Ferritic  Ann        135 to 185   110     450    515    130     500    575
Mar(410)  Ann        135 to 185   110     450    515    130     500    575
          Ann        175 to 225   100     400    460    120     450    520
          Q & T      275 to 325    60     250    285     75     300    345
          Q & T      375 to 425    40     150    175     50     175    200
Mar(431)  Ann        225 to 275    70     300    350     85     350    400
          Q & T      275 to 325    55     225    260     80     275    315
          Q & T (f)  375 to 425    40     150    175     50     175    200
Mar(440)  Ann        225 to 275    60     275    315     75     335    385
          Q & T      275 to 325    50     200    230     60     240    275
          Q & T (f)  375 to 425    40     150    175     50     175    200
          Q & T (e)  Rc48 to 52    20     100    115     30     125    140
          Q & T (g)  Rc54 to 56            55     65             70     80
Aus(304)  Ann        135 to 185    80     275    315    100     335    385
          CD         225 to 275    75     250    285     95     300    345
Aus(316)  Ann        135 to 185    70     250    285     90     300    345

 (b) Ann = Annealed      CD = Cold Drawn    Q & T = Quenched and tempered
     Hard = Hardened  N & T = Normalized & tempered  Rc = Rockwell C
 (c) Feed, .015 ipr
 (d) Feed, .007 ipr
 (e) Feed, high speed steel and carbide, .010 ipr for roughing, .005 ipr
      for finishing
 (f) Feed, high speed steel only, .010 ipr for roughing, .005 ipr for
      finishing
 (g)  Feed, carbide only, .005 ipr for roughing and finishing