National Machine Tool Company
Providing Keyway Solutions Since 1903
National Machine Tool Company | National Machine Tool Company Providing Keyway Solutions Since 1903

Feeds and Speeds

Operating guide and suggested spindle speed and feed rates for national keyseating millers and national oilgrooving millers

KEYSEAT MILLER NUMBER
PIN DRIVE
SPINDLE SPEED RPM CAST IRON
SPINDLE SPEED RPM MILD STEEL
SPINDLE SPEED RPM HARD STEEL
FEED/MIN CAST IRON in inches
FEED/MIN STEEL in inches
0-B
2
1600/1900
1000/1300
840
1-1/2
3/8
0-BS
2
1600/1900
1000/1300
840
1-1/2
3/8
0-A
2
1600/1900
1000/1300
840
1-1/2
3/8
0-AS
2
1600/1900
1000/1300
840
1-1/2
3/8
0
3
1500/1800
910/1250
840
1-1/2
3/8
0-S
2
1400/1650
910/1200
740
1-1/2
3/8
1
3
1000/1200
700/840
560
2
1/2
1-S
2
900/1080
650/780
520
2
1/2
2-B
3
900/1080
650/780
520
2
1/2
2-A
3
900/1080
650/780
520
2
1/2
2
3
900/1080
650/780
520
2
1/2
2-1/2B
3
900/1080
650/780
520
2
1/2
2-1/2A
3
900/1080
650/780
520
2
1/2
2-1/2AS
2
900/1080
650/780
520
2
1/2
2-1/2
3
900/1080
650/780
520
2
1/2
2-1/2S
2
900/1080
650/780
520
2
1/2
3-C
2
900/1080
650/780
520
2
1/2
3-B
3
750/900
650/780
500
2
1/2
3-A
3
750/900
650/780
500
2
1/2
3-AS
2
750/900
650/780
500
2
1/2
3
3
750/900
650/780
500
2
1/2
3-S
2
750/900
650/780
500
2
1/2
4-C
3
650/780
420/500
380
2
1/2
4-B
3
650/780
420/500
380
2
1/2
4-A & 4
3
650/780
420/500
380
2
1/2
4-A & 4
4
600/720
400/500
340
2
1/2
5-A & 5
3
400/480
260/320
205
2
3/8
5-A & 5
4
420/480
260/320
205
2
3/8
6-A & 6
3
400/480
240/320
190
2
3/8
6-A & 6
4
420/480
240/320
190
2
3/8
7-A & 7
3
350/420
220/320
180
2
3/8
7-A & 7
4
350/420
220/320
180
2
3/8

OILGROOVING MILLERS

0
3
1600/1900
1000/1250
840
1-1/2
5/8
1
3
1000/1200
700/840
560
2
5/8
2
3
900/1080
650/780
520
2
5/8
3
3
750/900
620/780
500
2
5/8
4
3
750/900
600/780
500
2
5/8

Cutting speeds and feeds for aluminum, brass, bronze, etc. will be approx., the same as shown for cast iron.

The spindle speed for cutting soft and mild steels is approx. 65% that of cast iron.

Hard steels and alloys are cut using spindle speed approx. 20% less than shown for mild steels. Feeds for cutting hard steels and alloys should be 50% less than shown for mild steels.

As a general rule narrow cutter widths can be run at faster feed/speed rates than the wider ones for each miller size.

Test your miller, prior to placing it into production, to determine exact spindle speed and feed rate best suited for your particular application. The above list is offered merely as a guide for initial set up.

ALWAYS USE SAFETY EYEWEAR WHILE USING THESE PRODUCTS

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