摘要 |
A method of selecting deformed bar for direct rolling of a thread thereon and also a method of threading such deformed bar. The method comprising rolling a preselected thread onto selected deformed bar without machining the bar in preparation. The bar selection is made so that the average cross-sectional area of the bar with the formed thread is substantially equal to that of the unthreaded portions of the bar. The formed thread is of continuous and substantially constant pitch circle. The method is particularly applicable in manufacture of rock bolts and anchor bolts from hot rolled deformed bar.
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