Allowable Tensile Stresses for Involute Splines

Material

Hardness

Maximum Allowable Shear [psi]

Brinell

Rockwell C

Steel

160 - 200

---

22 000

Steel

230 - 260

---

32 000

Steel

302 - 351

33 - 38

45 000

Surface-hardened Steel

---

48 - 53

45 000

Case-hardened Steel

---

58 - 63

55 000

Through-hardened Steel (Aircraft Quality)

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42 - 46

50 000