SYMPOSIA PAPER Published: 01 January 1953
STP45672S

Fatigue Properties of Large Specimens with Related Size and Statistical Effects

Source

This paper summarizes the results of rotating-bending fatigue tests on shafts 0.3- to 6-in. diameter from SAE plain carbon steels of 0.39 and 0.54 per cent carbon content in both the “as-forged” and normalized-and-tempered conditions. Shafts were tested with stress concentration, as represented by both fillets and press-fitted members, as well as plain specimens.

Shafts with stress concentration produced by fillets or press-fitted members from either untreated or normalized-and-tempered steels exhibited little or no size effect. An endurance limit ranging from 17,500 to 25,000 psi was found from tests on 101 plain specimens of 6-in. diameter untreated steel, while filleted shafts (r/d = 0.14 and 0.29) of the same material had endurance limit values within this range. A similar comparison exists on normalized-and-tempered steel, but here less extensive data are available.

Some effect of size was indicated on plain specimens 6 in. in diameter, which had a minimum endurance limit 35 per cent lower than that found for the conventional 0.3-in. diameter plain specimens from untreated steel. Data are reported on various groups of small specimens machined from large forgings and 22 in. bar stock.

Author Information

Horger, Oscar, J.
The Timken Roller Bearing Co., Canton, Ohio
Neifert, Harry, R.
The Timken Roller Bearing Co., Canton, Ohio
Price: $25.00
Contact Sales
Related
Reprints and Permissions
Reprints and copyright permissions can be requested through the
Copyright Clearance Center
Details
Developed by Committee: E08
Pages: 70–91
DOI: 10.1520/STP45672S
ISBN-EB: 978-0-8031-6260-0
ISBN-13: 978-0-8031-6251-8