1460898301-b5605fc4-b50f-4a77-a3d3-038173f7c812

What is claimed is:

1. A non-heat treated seamless steel tube having a composition consisting of, by weight,
C: 0.10 to 0.25%,
Si: 0.05 to 1.0%,
Mn: 0.5 to 2.5%,
P: not more than 0.03%,
S: not more than 0.05%,
Cr: 0.5 to 2.0%,
V: 0.03 to 0.3%,
Al: 0.003 to 0.10%,
N: 0.001 to 0.02%, and
O: not more than 0.003%,
wherein the balance comprises Fe and impurities, and
the carbon equivalent Ceq. (%) defined by the following equation is 0.60 to 0.85.
Ceq.CMn6(CrMoV)5(NiCu)15
2. The non-heat treated seamless steel tube according to claim 1, wherein a part of Fe is replaced with at least one kind selected from,
Ni: 0.05 to 1.5%,
Mo: 0.05 to 1.5%,
Cu: 0.05 to 1.5%, and
B: 0.0003 to 0.01%.
3. The non-heat treated seamless steel tube according to claim 1, wherein a part of Fe is replaced with one or 2 kinds selected from,
Ti: 0.005 to 0.2%, and
Nb: 0.005 to 0.2%.
4. The non-heat treated seamless steel tube according to claim 1, wherein a part of Fe is replaced with at least one kind selected from,
Ni: 0.05 to 1.5%,
Mo: 0.05 to 1.5%,
Cu: 0.05 to 1.5%, and
B: 0.0003 to 0.01%, and
replaced with one or 2 kinds selected from,
Ti: 0.005 to 0.2%, and
Nb: 0.005 to 0.2%.

The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.

1. A method for using a virtual center Y actuator to machine a work piece, comprising:
providing a work piece having a surface to be machined;
providing a virtual center Y actuator, the actuator comprising:
a main body having a back side, a front side, and a mounting block on the front side;
a flexible unit on the front side of the main body, wherein the flexible unit has a plurality of sides connected via flex points;
a piezoelectric stack secured and preloaded on the mounting block, and attached to the flexible unit, such that the piezoelectric stack extends substantially parallel to the front side of the main body;
a tool tip carrier attached to the flexible unit and having a surface for mounting a tool tip; and
a tool tip mounted on the surface of the tool tip carrier,
wherein the piezoelectric stack moves the flexible unit via the flex points in order to cause a rotation of the tool tip carrier about a y-direction axis substantially parallel to the surface of the work piece to be machined; and

using the actuator to create structures in the surface of the work piece to be machined, wherein the structures are created by the tool tip as controlled by the actuator.
2. The method of claim 1, further including a plate attached between the piezoelectric stack and the tool tip carrier for the preloading of the piezoelectric stack.
3. The method of claim 1, wherein the tool tip carrier includes a portion having an aperture for mounting the tool tip carrier to the flexible unit.
4. The method of claim 1, wherein the tool tip carrier has a planar back surface mounted to the flexible unit.
5. The method of claim 4, wherein the tool tip carrier has a tapered front surface opposite the planar back surface.
6. The method of claim 1, wherein the piezoelectric stack is comprised of one of the following materials: barium titanate; lead zirconate; lead titanate; or a magnetostrictive material.
7. The method of claim 1, wherein the main body includes an aperture having a port for receiving a cooling fluid.
8. The method of claim 2, wherein the plate comprises a Belleville washer.
9. The method of claim 1, wherein the main body is comprised of stainless steel.
10. The method of claim 1, wherein the main body is configured to be removably attached to a tool post.
11. The method of claim 1, wherein the work piece is comprised of one of the following materials: copper; aluminum; nickel; steel; or plastic.