Abstract: A flat spring hose clamp having an improved resistance to brittle fracture and a method for manufacturing the same are disclosed, the hose clamp being made of a steel having a steel composition consisting essentially of, by weight %:C:0.30-0.70%,Si: 0.70% or less,Mn: 0.05-1.00%,P: 0.030% or less,S: 0.020% or less,Cr: 0.50-2.00%,Mo: 0.10-0.50%,Nb: 0.005-0.100%,sol. Al: 0.10% or less,N: more than 0.0020%, but not more than 0.015%,Ti: 0-0.10% and/or B: 0-0.0020%,and a balance of Fe and incidental impurities, and the steel possessing a uniform bainite structure.

Abstract: A process for the production of a stainless steel strip having excellent spring characteristics as such and good formability, wherein a cold rolled strip of a stainless steel comprising, in addition to Fe, from 10.0 to 20.0% by weight of Cr, from 0.01 to 0.15% by weight of C, and at least one of Ni, Mn and Cu in an amount of from 0.1 to 4.0% by weight, is continuously passed through a continuous heat treatment furnace where it is heated to a temperature range for a two-phase of ferrite and austenite, rapidly cooled to provide a strip of a duplex structure, consisting essentially of ferrite and martensite, optionally temper rolled at a rolling reduction of not more than 10%, and continuously passed through a continuous heat treatment furnace to effect aging of not longer than 10 minutes.

Abstract: The present invention relates to a high-strength coil spring useful for an engine and other high-strength springs requiring a high fatigue-resistance and a method of producing the same.In general, a higher tensile strength is desired for spring materials but it has been known that if a tensile strength exceeds a certain limit, a toughness and a fatigue resistance are contrarily reduced.In addition, a coil spring has been used after forming and then being subjected to a quenching treatment followed by being subjected to a shot peening treatment to add a compressive residual stress to a surface thereof but an effective shot peening treatment gives a surface roughness Rmax of 6 to 20 .mu.m, so that not only it has been impossible to remove surface defects having a surface roughness of 6 to 20 .mu.m or less but also impressions due to the shot peening have covered the surface defects to be turned into injured portions and fatigue nuclei in many cases.