Group "A" Shapes with 1/4" Mandrels - Maximum RPM Ratings
Shape No.
Wheel Diameter
Wheel Thickness
1/2" Overhang
1" Overhang
1-1/2" Overhang
A1
3/4
2-1/2
19800
61500
13120
A3
1
2-3/4
16100
13080
10730
A4
1-1/4
1-1/4
30560
24750
20250
A5
3/4
1-1/8
45000
33750
27000
A11
7/8
2
19860
15100
12000
A12
11/16
1-1/4
48000
35250
27370
A13
1-1/8
1-1/8
33950
32250
25500
A14
11/16
7/8
55560
40500
30750
A15
1/4
1-1/16
72750
47620
34500
A21
1
1
34500
26250
21000
A23
3/4
1
39370
30370
24370
A24
1/4
3/4
76500
49500
36370
A25
1
1
35620
27370
22120
A26
5/8
5/8
61120
46500
35250
A34
1-1/2
3/8
25470
25470
25470
A35
1
3/8
38200
38200
31500
A36
1-5/8
3/8
23520
23520
23520
A37
1-1/4
1/4
30560
30560
30560
Group "B" Shapes with 1/8" Mandrels - Maximum RPM Ratings
Shape No.
Wheel Diameter
Wheel Thickness
1/2" Overhang
1" Overhang
1-1/2" Overhang
B41
5/8
5/8
33750
23250
17620
B42
1/2
3/4
33750
23250
17620
B51
7/16
3/4
45370
28500
21000
B52
3/8
3/4
45370
28500
21000
B61
3/4
5/16
38250
24370
17400
B62
1/2
3/8
41020
26400
19500
B91
1/2
5/8
34500
22500
16870
B104
5/16
3/8
68400
42370
22870
B111
7/16
11/16
33750
23250
17620
B112
3/8
1/2
45370
28500
21000
B121
1/2
1/2
45370
28500
21000
B122
3/8
3/8
61650
37720
27000
Group "W" Shapes with 1/8" Mandrels - Maximum RPM Ratings
Shape No.
Wheel Diameter
Wheel Thickness
1/2" Overhang
1" Overhang
1-1/2" Overhang
W160
1/4
1/4
81370
51000
34120
W162
1/4
3/8
68370
42370
28870
W163
1/4
1/2
60000
38020
26250
W164
1/4
3/4
45900
30000
21750
W174
3/8
1/4
69000
41250
27750
W175
3/8
3/8
54000
33000
24150
W176
3/8
1/2
45370
28500
21000
W177
3/8
3/4
33750
23250
17620
W178
3/8
1
26250
18750
14250
W183
1/2
1/4
51570
31870
22500
W184
1/2
3/8
41020
26400
19500
W185
1/2
1/2
34500
22500
16870
W186
1/2
3/4
26250
17400
12750
W187
1/2
1
20260
13870
10120
W201
3/4
1/4
38250
24370
17400
W202
3/4
3/8
30600
19500
13500
W203
3/4
1/2
25500
15900
10870
W216
1
1/4
30520
18600
12750
Group "W" Shapes with 1/4" Mandrels - Maximum RPM Ratings
Shape No.
Wheel Diameter
Wheel Thickness
1/2" Overhang
1" Overhang
1-1/2" Overhang
W176
3/8
1/2
81000
54380
42000
W177
3/8
3/4
66000
46500
32250
W178
3/8
1
55200
40500
30000
W179
3/8
1-1/4
45750
33750
25720
W183
1/2
1/4
76390
54750
40500
W184
1/2
3/8
71250
47620
35020
W185
1/2
1/2
61500
42000
31500
W186
1/2
3/4
51000
36370
27750
W187
1/2
1
40500
30000
24000
W188
1/2
1-1/2
30370
24000
18900
W189
1/2
2
24000
18750
15000
W196
5/8
1
35250
27000
21300
W197
5/8
2
21000
16500
12900
W201
3/4
1/4
50390
50930
38100
W202
3/4
3/8
50390
44100
32400
W203
3/4
1/2
50390
36370
27750
W204
3/4
3/4
42750
30750
23250
W205
3/4
1
34500
25870
19500
W207
3/4
1-1/2
24000
18520
14620
W208
3/4
2
18750
15370
12000
W216
1
1/4
38200
38200
33750
W217
1
3/8
38200
38200
28500
W218
1
1/2
38200
32770
24900
W220
1
1
25500
19120
15750
W221
1
1-1/2
19120
14620
12000
W222
1
2
15900
12370
9750
W225
1-1/4
1/4
30560
30560
30560
W226
1-1/4
3/8
30560
30560
26250
W227
1-1/4
1/2
30560
29620
22650
W228
1-1/4
3/4
30520
22500
17850
W230
1-1/4
1-1/4
20400
15900
12750
W232
1-1/4
2
14250
10650
9000
W235
1-1/4
1/4
25470
25470
25470
W236
1-1/4
1/3
25470
25470
21750
W237
1-1/4
1
22500
17620
13270
W238
1-1/4
1-1/2
15600
12000
9750
W242
2
1
19100
15950
11750
