For the purpose of expressing quantitatively, the effects of heat-treatment on the spring and wire materials, the authors have designed a bending tester, called “stiffness tester, ” to adopting for testing these small sized materials, We have made several experiments on the adaptability of this instrument, Specimens made in the experiment are spring materials with eutectoid composition of carbon steel, By investigating for several quenching temperatures, we find that 780°C is the most suitable one for obtaining high hardness without reducing in the bending load. Specimens tempered at 100°C-650°C after quenching to 780°C and those austempered are also tested to compare their hardness.
Results obtained are summarized as follows:
(1) In the bending test, the specimens were settled in the vice which has a radius of curvature R. We measured the maximum bending load, bending angle, absorbed energy in bending and permanent set angle, which will be a quantitative expression of the mechanical properties of spring materials.
(2) The smaller the radius of curvature of vice to which the specimens are settled is the more sensitively the effects of the tempering temperature appear.
(3) Comparing the specimen tempered after quenching and that austempered, the latter is more ductile than the former.
(4) This tester is available to even those specimens quenched with sufficient sensitivity.

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As the lead metals are of comparatively high purity, the chemical analysis is not suitable for quantitative determination of slight impurities in these metals.
The authors, therefore, have studied the spectrum analysis of small amounts of impurities in lead metals, using an intermitent arc with the Shimadzu littrow type large quarts spectrograph and its accessories.
The experiments were done under the following conditions: pin type electrode, electrode gap 2mm, slit width 30 micron, Feussner circuit L=0, C=0.0033μF, primary volt. 50V; Intermittence ratio of intermittent apparatus 1/20, occurrences of intermittence 1/sec, arc current A.C 220V. 5A and the step filter (26%-100%-4%) used in front of the slit.
The spectrum was recorded on spectrographic plates, which were developed for 3 minutes with continuous agitation in a constant temperature tank with Fuji FD-31 developer.
Spectral intensity was measured using a microphotometer and the following analytical line pairs were measured: Ag 3382.9/Pb 3220.5, Cu 3274.0/Pb 3220.5, Bi 3067.7/Pb 3220.5, Sn 3175.0/Pb 3220.5 and Sb 2598.1/Pb 3220.5Å.
The ranges which were determined are 0.0001-0.007% Ag, 0.001-0.07% Cu, 0.001-0.035% Bi, 0.001-0.07% Sn and 0.002-0.14% Sb.
The results obtained were summarized as follows:
1) The simultaneous estimation of Ag, Cu, Bi and Sn is made easily and rapidly, but the determinatian of small amounts (<0.006%) of Sb by means of the pin type electrodes was difficult.
2) Reproducibility of the spectrum value was fine within the standard deviation of 3 to 5% except for the low content of Sb.

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The tenacity and the elongation of tire cord, especially rayon tire cord, are usually expressed as the so-called “bone dry tenacity and elongation.” By the method usually adopted for bone drying, cords are dryed in an air oven at 105-110°C for 2-3 hours for the measurement.
We have studied the bone drying by infrared rays with the view of shortening the time for drying and found that the time for drying is greatly shortened (within about 30sec) and drying proceeds more rapidly and thereby the values of the tenacity are given as a larger value than in the usual bone drying.
The equipment for this purpose is composed of; (I) the heatresisting steel pipe (8mmφ×500mm (1) heated at 500-600°C in surface temperature by internal electrical supply (100V-700W) (II) the metalic reflector of conduit form which has a parabolical section and of which focus is placed in the steel pipe so as to give the parallel heat rays, and (III) another reflector of the same construction which is placed at the opposite side face to face so as to collect the parallel heat ray in its focus where the tire cord passes along so as to be subjected to rapid drying.
The drying speed and extent of tire cord is adjustable by the voltage of electrical supply and the surrounding temperature and also the passing speed of tire cord.
The values of the tenacity are varied by the absorption of moisture which takes place during the processes from drying to measurement. This variance results from the uneven deposition of moisture (from the surface to the inner parts of tire cord) even in the same average moisture content and largely from the residual twist number (ply twist-cord twist).

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This paper contains the results of the notched impact bending test compared with Charpy impact bending test. The specimen used is a cylinder notched around the circumference and the impact was given at two points at both sides of the notch. The effects of the notch were principally tested, and furthermore to test whether this two points impact system is practically applicable or not as the impact bending test, carbon steel specimens heattreated were tested and compared with the Charpy test.
As the testing apparatus, the Charpy impact tester was used with a new pendulum of two points impact shown in Fig. 1. The dimension of the specimen is shown in Fig. 2.
In doing the experiment, the uniformity of the material was especially considered and annealed in a vacuum furnace.
Fig. 3, 4 and 5 show the notch effect, and Fig. 6 shows the effect of the heat treatments.
From the results of the experiment it was found that if the Mesnager type specimen is employed as the standard only slightly changing the dimensions of the notch; this new type of two points impacts test can be substituded for the Charpy test with better results. In this case the authors recommend a specimen with an external diameter of 10mm and an effective diameter of the section at the bottom of the notch of 7.5mm.
This new type of cylindrical specimen can be more easily made and set for testing compared with Charpy or Izod type. Further more as the amount of the shearing stress against the normal stress induced during the test is larger than that of the Mesnager type, this new type is more sensitive to the influence of the dimension of the notch, testing temperature and impact velocity etc. compared with the Mesnager type.

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Usually the carbon steel wire contains about 0.1% copper, but an investigation was made on copper bearing steel wire in which the copper content was made greater than that of carbon steel wire in order to increase the corrosion resistance of the wire itself. In view of the corrosion resistance and the rolling crack, a copper content of 0.34% was adopted as the copper content of the copper bearing steel wire. In this investigation, the corrosion resistance properties and the mechanical properties, particularly the fatigue property of the cold-drawn copper bearing steel wire and the cold-drawn carbon steel wire containing the same compositions except copper were measured. These wires tested contained 0.46% carbon and the diameters were 1.3mm.
In the corrosion test and the tensile test, the copper bearing steel wire had an excellent resistance against the rust corrosion and the acid corrosion and also had a higher tensile strength than the carbon steel wire. The fatigue test was carried out with the Hunter fatigue testing machine, and as a result of the test it was proved that the fatigue limit under rotating bending of the copper bearing steel wire was 7% higher in the as-drawn condition and 6% higher in the 250°C annealed condition than that of the carbon steel wire, and also that the fatigue ratio of the copper bearing steel wire was about 3% larger in both condition than that of the carbon steel wire.
From the results obtained by the corrosion test and the fatigue test, it is deduced that the copper bearing steel wire will have remarkably higher corrosion fatigue strength than the carbon steel wire, and consequently that the strand and the rope produced by the copper bearing steel wire will have greater durability.

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