The tensile strength of steel increases by reheating and rolling up to the second operation, but decreases after that.

The relative resistance of wrought iron and copper to tension and compression is as 100 to 54.5.

Transverse Strength

The Transverse or Lateral Strength of any Bar, Beam, Rod, etc., is in proportion to the product of its breadth and the square of its depth; in like-sided beams, bars, etc., it is as the cube of the diameter of the section.

When one end is fixed and the other projecting, the strength is inversely as the distance of the weight from the section acted upon; and the strain upon any section is directly as the distance of the weight from that section.

When both ends are supported only, the strength is 4 times greater for an equal length, when the weight is applied in the middle between the supports, than if one end only is fixed.

When both ends are fixed, the strength is 6 times greater for an equal length, when the weight is applied in the middle, than if one end only is fixed.

The strength of any beam, bar, etc., to support a weight in the centre of it, when the end rests merely upon two supports, compared to one when the ends are fixed, is as 2 to 3.

When the weight or strain is uniformly distributed, the weight or strain that can be supported, compared with that when the weight or strain is applied at one end or in the middle between the supports, is as 2 to 1.

In metals, the less the dimension of the side of a beam, etc., or the diameter of a cylinder, the greater its proportionate transverse strength. This is in consequence of their having a greater proportion of chilled or hammered surface compared to their elements of strength, resulting from dimensions alone.

The strength of a cylinder, compared to a square of like diameter or sides, is as 6.25 to 8. The strength of a hollow cylinder to that of a solid cylinder, of the same length and volume, is as the greater diameter of the former is to the diameter of the latter.

The strength of an equilateral triangle, fixed at one end and loaded at the other, having an edge up, compared to a square of the same area, is as 22 to 27; and the strength of an equilateral triangle, having an edge down, compared to one with an edge up, is as 10 to 7.

Note

In these comparisons, the beam, bar, etc., is considered as one end being fixed, the weight suspended from the other. In Barlow and other authors the comparison is made when the beam, etc., rested upon supports. Hence the stress is contrariwise.

Detrusion is the resistance that the particles or fibres of materials oppose to their sliding upon each other. Punching and shearing are detrusive strains.