A metal foil for a spring member includes a first region on which the spring member is formed. The first region has a square shape with one side being 300 mm. In the first region, an absolute value of a difference value obtained by subtracting variance of a thickness in a width direction orthogonal to a rolling direction from variance of a thickness in the rolling direction is less than or equal to 0.15 m.sup.2.

A metal foil for a spring member includes a first region on which the spring member is formed. The first region has a square shape with one side being 300 mm. In the first region, an absolute value of a difference value obtained by subtracting a standard deviation of a thickness in a width direction orthogonal to a rolling direction from a standard deviation of a thickness in the rolling direction is less than or equal to 0.15 m.

The seamless pipe in which a thin-walled portion in a pipe circumferential direction is formed in a pipe axial direction, in which a line segment formed by connecting one end and the other end of the thin-walled portion along a pipe surface with a shortest distance in a formation direction of the thin-walled portion is inclined at an angle of 5.0 or more with respect to the pipe axial direction. It is preferable that one end and the other end of the thin-walled portion are set from a region in a pipe selected with a shorter length between a length of 1.0 m in the pipe axial direction and 90% of a length in the pipe axial direction where the thin-walled portion turns once in the pipe circumferential direction.

In a ferritic stainless steel sheet, the arithmetic average roughness Ra is 0.2 m or more and 1.2 m or less. In addition, the dull pattern transfer rate on the steel sheet surface is 15% or more and 70% or less. Furthermore, micropits with a depth of 0.5 m or more and an open area of 10 m.sup.2 or more which are formed on the steel sheet surface have an existing density of 10.0 or less per 0.01 mm.sup.2 and an open area ratio of 1.0% or less. In addition, a film formed on the steel sheet surface is constituted from an oxide containing SiO.sub.2 as a main constituent, which oxide contains at least Si, N, Al, Mn, Cr, Fe, Nb, Ti and O as film-forming elements other than C, wherein the Si content is 10 at % or more, and the N content is 10 at % or less.

A rolled metal sheet includes an obverse surface and a reverse surface that is a surface located opposite to the obverse surface. At least either one of the obverse surface and the reverse surface is a processing object. A method for manufacturing a metal mask substrate includes reducing a thickness of the rolled metal sheet to 10 m or less by etching the processing object by 3 m or more by use of an acidic etching liquid, and roughening the processing object so that the processing object becomes a resist formation surface that has a surface roughness Rz of 0.2 m or more, thereby obtaining a metal mask sheet.

A manufacturing method of a seamless metal pipe includes: preparing a plurality of mandrel bars in which lengths of work portions which come into contact with a hollow shell during elongating are different from one another; selecting a mandrel bar including a work portion having a length corresponding to the number of stands used in thickness reduction, among the plurality of mandrel bars; inserting the mandrel bar selected in the selecting into the hollow shell; and performing the elongating on the hollow shell into which the mandrel bar is inserted. Moreover, in the elongating, outer diameter reduction is performed by one of a preceding-stage stand group and a succeeding-stage stand group and the thickness reduction is performed by the other of the preceding-stage stand group and the succeeding-stage stand group, or the thickness reduction is performed by both of the preceding-stage stand group and the succeeding-stage stand group.

An electrode sheet manufacturing device includes a pair of rolls that press an electrode active material layer formed on an electrode sheet, a press pressure adjusting mechanism that adjusts a press pressure of the pair of rolls, a temperature sensor that detects a surface temperature of at least one of the pair of rolls, and a controller. The controller is configured to adjust the press pressure, based on the surface temperature of the at least one of the pair of rolls detected by the temperature sensor.

The invention relates to a cooling method for a rolling ingot of aluminium alloy after metallurgical homogenization heat treatment of said ingot and before hot rolling, characterized in that cooling by 30 to 150 C. is performed at a rate of 150 to 500 C./h, with a homogeneity of less than 40 C. throughout the treated portion of the ingot.

The invention also relates to the facility allowing use of said method and said implementation.

A six-high rolling (also known as sexto) mill stand that is suited for hot rolling an intermediate strip into a thin strip that is less than 0.8 mm thick. A combined casting and rolling installation that includes the six-high rolling mill stand allowing for hot rolling in long uninterrupted sequences, without any change of the work rolls to obtain a strip with good geometry due to moderate rolling forces.

Rolling method to produce a metal strip (P) in coil-to-coil, semi-endless or endless mode, in a rolling plant (10) comprising: a continuous casting device (11) to produce slabs; a furnace (16) configured to maintain the slabs at a certain temperature and/or to heat the slabs; at least one roughing stand (25) to reduce the thickness of the slabs and obtain an intermediate rolled product; a plurality of finishing stands (31) to reduce the thickness of the intermediate rolled product and obtain the strip (P); a rapid heating device (28) interposed between the at least one roughing stand (25) and the plurality of finishing stands (31) to heat the intermediate rolled product in each operating mode, so that the temperature of the strip (P) in correspondence with the outlet of the last finishing stand (31) is comprised between 830 C. and 860 C.