TY - RPRT TI - Letter Circular 405: testing machines for determining the strength and other properties of engineering materials in the laboratories of the National Bureau of Standards, Department of Commerce, Washington, D.C. PY - 1934 PB - National Institute of Standards and Technology CY - Gaithersburg, MD SN - LCIRC 405 DO - 10.6028/NBS.LCIRC.405 ER -