Allowable Shear Stresses for Involute Splines

Material

Hardness

Maximum Allowable Shear [psi]

Brinell

Rockwell C

Steel

160 - 200

---

20 000

 

Steel

230 - 260

---

30 000

 

Steel

302 - 351

33 - 38

40 000

 

Surface-hardened Steel

---

48 - 53

40 000

 

Case-hardened Steel

---

58 - 63

50 000

 

Through-hardened Steel (Aircraft Quality)

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42 - 46

45 000