Machinery's Handbook, 31st Edition
Shafts
299
Diameters of Finished Shafting (former American Standard ASA B17.1 ) Diameters, Inches Diameters, Inches Diameters, Inches
Minus Toler ances, Inches a 0.002 0.002 0.002
Minus Toler ances Inches a 0.003 0.003 0.003
Minus Tolerances, Inches a
Transmis sion Shafting
Transmis sion Shafting
Transmis sion Shafting
Machinery Shafting
Machinery Shafting
Machinery Shafting
0.004 0.004 0.004 0.005 0.005 0.005 0.005 0.005 0.005 0.005 0.005 0.006 0.006 0.006 0.006 0.006 0.006 0.006 0.006
1 13 ∕ 16
3 3 ∕ 4 3 7 ∕ 8 4 1 ∕ 4 4 1 ∕ 2 4 3 ∕ 4 4 5 1 ∕ 4 5 1 ∕ 2 5 3 ∕ 4 6 1 ∕ 4 6 1 ∕ 2 6 3 ∕ 4 5 6 7 1 ∕ 4 7 1 ∕ 2 7 3 ∕ 4 7
1 ∕ 2
1 7 ∕ 8
9 ∕ 16
1 15 ∕ 16
1 15 ∕ 16
3 15 ∕ 16
5 ∕ 8
0.002 0.002 0.002 0.002 0.002 0.002 0.003 0.003 0.003 0.003 0.003 0.003 0.003 0.003 0.003 0.003 0.003 0.003
2
0.003 0.004 0.004 0.004 0.004 0.004 0.004 0.004 0.004 0.004 0.004 0.004 0.004 0.004 0.004 0.004 0.004 0.004
11 ∕ 16
2 1 ∕ 16 2 1 ∕ 8 2 3 ∕ 16 2 1 ∕ 4 2 5 ∕ 16 2 3 ∕ 8 2 7 ∕ 16 2 1 ∕ 2
4 7 ∕ 16
3 ∕ 4
13 ∕ 16
2 3 ∕ 16
4 15 ∕ 16
7 ∕ 8
15 ∕ 16
15 ∕ 16
1
5 7 ∕ 16
1 1 ∕ 16 1 1 ∕ 8 1 3 ∕ 16 1 1 ∕ 4 1 5 ∕ 16 1 3 ∕ 8 1 7 ∕ 16 1 1 ∕ 2 1 9 ∕ 16 1 5 ∕ 8 1 11 ∕ 16
2 7 ∕ 16
5 15 ∕ 16
1 3 ∕ 16
2 5 ∕ 8 2 3 ∕ 4 2 7 ∕ 8 3 1 ∕ 8 3 1 ∕ 4 3 3 ∕ 8 3 1 ∕ 2 3
6 1 ∕ 2
7
2 15 ∕ 16
1 7 ∕ 16
7 1 ∕ 2
8
8
… …
… …
…
1 11 ∕ 16
3 7 ∕ 16
1 3 ∕ 4 … a Note:— These tolerances are negative or minus and represent the maximum allowable variation below the exact nominal size. For instance the maximum diameter of the 1 15 ⁄ 16 inch shaft is 1.938 inch and its minimum allowable diameter is 1.935 inch. Stock lengths of finished transmis sion shafting shall be: 16, 20 and 24 feet. 3 5 ∕ 8 Design of Transmission Shafting.— The following guidelines for the design of shafting for transmitting a given amount of power under various conditions of loading are based upon formulas given in the former American Standard ASA B17c Code for the Design of Transmission Shafting. These formulas are based on the maximum-shear theory of fail- ure which assumes that the elastic limit of a ductile ferrous material in shear is practically one-half its elastic limit in tension. This theory agrees, very nearly, with the results of tests on ductile materials and has gained wide acceptance in practice. The formulas given apply in all shaft designs including shafts for special machinery. The limitation of these formulas is that they provide only for the strength of shafting and are not concerned with the torsional or lineal deformations which may, in shafts used in machine design, be the controlling factor (see Torsional Deflection of Circular Shafts on page 297 and Linear Deflection of Shafting on page 298 for deflection considerations). In the formulas that follow, B = K 1 1 4 3 ' − ^ h (see Table 3) D = outside diameter of shaft in inches D 1 = inside diameter of a hollow shaft in inches K m = shock and fatigue factor to be applied in every case to the computed bending moment (see Table 1) K t = combined shock and fatigue factor to be applied in every case to the computed torsional moment (see Table 1) M = maximum bending moment in inch-pounds N = revolutions per minute P = maximum power to be transmitted by the shaft in horsepower
Copyright 2020, Industrial Press, Inc.
ebooks.industrialpress.com
Made with FlippingBook - Share PDF online