Setting Lathe Speed
Id hZi i]Z XdggZXi aVi]Z he^cYaZ heZZY [dg ndjg deZgVi^dc! ndj l^aa cZZY id/ & 9ZiZgb^cZ i]Z he^cYaZheZZYGEBcZZYZY[dgndjgldg`e^ZXZ bViZg^Va!VcY'Xdc[^\jgZi]ZaVi]ZK"WZaih[dgi]Z XVaXjaViZYhe^cYaZheZZY#
Calculating Correct Spindle Speed
1. JhZi]ZiVWaZ^cFigure 54 idYZiZgb^cZi]Z gZXdbbZcY Xjii^c\ heZZY [dg i]Z ldg`e^ZXZ bViZg^Va#
Note: Cutting speeds are expressed in sur- face feet cut per minute (SFM).
Recommended Cutting Speeds
| 6kZgV\ZIddaHeZZYh[b | |
Ldg`BViZg^Va | Rough Cuts | Finish Cuts |
BV\cZh^jb | )%% | |
6ajb^cjb | (*% | ,%% |
7gVhh7gdcoZ | '*% | *%% |
8deeZg | &%% | '*% |
8Vhi>gdcHd[i | &%% | '*% |
8Vhi>gdc=VgY | *% | &*% |
B^aYHiZZa | &%% | '*% |
8VhiHiZZa | ,% | &*% |
6aadnHiZZah=VgY | *% | &*% |
IddaHiZZa | *% | &*% |
HiV^caZhhHiZZa | +% | |
I^iVc^jb | .% | '%% |
=^BV\VcZhZHiZZa | )% | &%% |
Note: These values are based on HSS cutting tools. For carbide cutting tools, double the aver- age speed. These values are a guideline only. Refer to the MACHINERY’S HANDBOOK for more detailed information.
Figure 54.GZXdbbZcYXjii^c\heZZYiVWaZ#
")'"
2. 9ZiZgb^cZ i]Z [^cVa Y^VbZiZg! ^c ^cX]Zh! [dg i]ZXjindj^ciZcYidbV`Z#
Note: For this step, you will need to average out the diameters or work with the finished diameter.
3. JhZ i]Z [daadl^c\ [dgbjaV id YZiZgb^cZ i]Z XdggZXihe^cYaZheZZYGEB[dgndjgdeZgV" i^dc/
Cutting Speed (SFM) x 4
Spindle Speed =
Diameter of Cut
Example A
Ndjl^aabV`ZV&¿'Y^VbZiZg[^c^h]XjidcV XVhi hiZZa ldg`e^ZXZ! jh^c\ Vc =HH Xjii^c\ idda#
Step 1:
&*%H;B[gdbX]Vgim)2+%%
Step 2:
+%%$#*9^VbZiZgd[Xji2&'%%
Result:
I]ZXdggZXihe^cYaZheZZY^h&'%%GEB#
Example B
Ndj l^aa bV`Z V & Y^VbZiZg gdj\] Xji dc V hiV^caZhh hiZZa ldg`e^ZXZ! jh^c\ V XVgW^YZ Xjii^c\idda#
Step 1:
+% H;B [gdb X]Vgi m ' [dg XVgW^YZ idda 2 &'%
Step 2:
Step 3:
Result: