Axles. Driving and engine truck axles are made of open hearth steel, having a tensile strength not less than 80,000 pounds per square inch. Modern practice requires that axles conform to the tests and standards adopted by the American Railway Master Mechanics' Association and the American Society for Testing Materials. One axle is required to be tested from each heat. The test piece may be taken from the end of any axle with a hollow drill, the hole made by the drill to be not more than 2 inches in diameter nor more than 4½ inches deep. This test piece is to be subjected to the physical and chemical tests provided for in the code of the societies mentioned above.All forgings must be free from seams, pipes, and other defects, and must conform to the drawings furnished by the company. The forgings, when specified, must be weighed, turned with a flat nosed tool, and cut to exact length and centered with 60 degree centers. All forgings not meeting the above requirements or which are found to be defective in machining and which cannot stand the physical chemical tests will be rejected at the expense of the manufacturers.
The above requirements, while intended for driving axles, apply in a general way to engine truck axles. Axles are forged from steel billets, of the proper size to conform to the size of the axles as required for standard gauge work.
In accordance with the foregoing, Table XIV is presented, which gives the sizes and the weights of billets for standard driving and engine truck axles.
TABLE XIV
Forged Steel Billets
(Standard Sizes)
DRIVING AXLES ENGINE TRUCK AXLES Diameter of Journal, Inches Size of Billet, Inches Weight of Billet, Pounds Diameter of Journal, Inches Size of Billet, Inches Weight of Billet, Pounds 8 10 x 10 2590 5 7 x 7 970 8½ 11 x 11 2900 5½ 7 x 7 1170 9 11 x 11 3220 6 8 x 8 1380 9½ 12 x 12 3570 6½ 8 x 8 1600 10 12 x 12 3930 7 9 x 9 1830 After the axles are received in the rough state, the journals and wheel fits are turned up, in the shop, to the proper dimensions. In turning up the wheel fits, they are left slightly larger in diameter than the diameter of the axle opening in the wheel center. The wheel center is then forced on the axle by means of hydraulic pressure. Table XV gives the pressure employed in forcing-in engine truck and driving axles.
TABLE XV
Hydraulic Pressures Used in Mounting Axles
DRIVING AXLES ENGINE TRUCK AXLES Diameter of Fit in Inches Pressure Employed in Tons Diameter of Fit in Inches Pressure Employed in Tons Cast-Iron Center Cast-Steel Center Cast-Iron Center Cast-Steel Center 7 - 7½ 70 - 75 112 - 120 4 - 4½ 25 - 30 37 - 45 7½ - 8 75 - 80 120 - 128 4½ - 5 30 - 35 45-52 8 - 8½ 80 - 85 128 - 136 5 - 5½ 35 - 40 52 - 60 8½ - 9 85 - 90 136 - 144 5½ - 6 40 - 45 60 - 67 9 - 9½ 90 - 95 144 - 152 6 - 6½ 45 - 50 67 - 75 9½ - 10 95 - 100 152 - 160 6½ - 7 50 - 55 75 - 82 10 - 10½ 100 - 105 160 - 168 7 - 7½ 55 - 60 82 - 90 10½ - 11 105 - 110 168 - 176
Table of Contents; Page 100; Page 106; Index
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