DETAILED ACTION
Response to Amendment
The Amendment filed 08 May 2026 has been entered. Claims 1-4 remain pending in the application. No new claims have been added. Applicant's amendments to the claims have overcome the 112(b) rejections previously set forth in the Non-Final Rejection mailed 11 February 2026.
Priority
Acknowledgment is made of applicant’s claim for foreign priority under 35 U.S.C. 119 (a)-(d). Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55.
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claims 1-4 are rejected under 35 U.S.C. 103 as being unpatentable over US20180274703 of Goto.
Claim 1 claims An oil-well steel pipe, comprising: a pipe main body including a first end portion and a second end portion; a chemical composition of the pipe main body containing, in mass%: C: 0.01 to 0.60%, Cr: 0 to 8.0%, and Fe: 80.0% or more; wherein the pipe main body includes: a pin formed at the first end portion, and a box formed at the second end portion; the pin includes: a pin contact surface including an external thread part; and the box includes: a box contact surface including an internal thread part; the oil-well steel pipe further comprising: a Zn-Ni alloy plating layer formed on at least one of the pin contact surface and the box contact surface, wherein when a region containing C in an amount that, in mass%, is 1.5 times or more greater than a C content of the pipe main body is defined as a C- concentrated layer, in the Zn-Ni alloy plating layer, a thickness of the C-concentrated layer in a wall thickness direction of the pipe main body is within a range of 0 to 1.50 pm.
Goto teaches a Composition, Threaded Joint for Pipes Including Solid Lubricant Coating Formed from the Composition, and Method for Producing the Threaded Joint for Pipes in the same field of endeavor as the claimed invention. Goto discloses that typical threaded joint for pipes include a pin and a box. The pin includes a male threaded portion and an unthreaded metal contact portion formed in the outer peripheral surface at the end of the pipe. The box includes a female threaded portion and an unthreaded metal contact portion formed in the inner peripheral surface at the end of the pipe, Para[0003]. Goto teaches that the steel grades of the threaded joint for pipes were carbon steels, Para[0120]. It is well known in the art that carbon steels are iron alloys with carbon in the range of 0.05-2.1%. Goto also discloses steels with a value for chromium in the range of 0.17-13.0%, Para[0120]. The values disclosed for carbon, iron, and chromium overlap with the claimed ranges. In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists, see MPEP 2144.05. Goto also discloses Zi-Ni alloy plating on the pin and box surfaces, Para[0128]. While Goto does not teach a “C-concentrated layer”, Goto teaches a pickling treatment, Para[0100]. One of ordinary skill in the art performing the pickling treatment taught by Goto under well-known conditions would necessarily produce a C-concentration layer meeting the properties of the claim. Where the claimed and prior art products are identical or substantially identical in structure or composition, or are produced by identical or substantially identical processes, a prima facie case of either anticipation or obviousness has been established, see MPEP 2112.01. Additionally, the C-concentration layer is an optional limitation as described at paragraph [0073] of the instant specification. Thus, Goto covers all limitations of claim 1. Claims 2-4 are rejected as they depend on claim 1.
Claim 2 further limits claim 1 by claiming a thickness of the Zn-Ni alloy plating layer is within a range of 5 to 25 µm.
Goto discloses that the thickness of the plating layer is preferably in the range of 5 to 15 µm. This overlaps with the claimed range. In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists, see MPEP 2144.05. Therefore, Goto covers all limitations of claim 2.
Claim 3 further limits claim 1 by claiming a lubricant coating on or above the Zn-Ni alloy plating layer.
Goto teaches a lubricant coating over the Zn-Ni plating, Para[0128],[0129]. Therefore, Goto covers all limitations of claim 3.
Claim 4 further limits claim 2 by claiming a lubricant coating on or above the Zn-Ni alloy plating layer.
Goto teaches a lubricant coating over the Zn-Ni plating, Para[0128],[0129]. Therefore, Goto covers all limitations of claim 4.
Response to Arguments
Applicant's arguments filed 08 May 2026 have been fully considered but they are not persuasive. Applicant argues that (remarks, pages 6 and 7 of 9) primary reference Goto does not teach the claimed product because Goto does not disclose a C-concentrated layer with a thickness in the range of 0 to 1.50 µm. Additionally, applicant argues that (remarks, page 6 of 9) since Goto lacks any disclosure or suggestion of structurally restricting the thickness of the C-concentrated layer, it is reasonable to assume that the C-concentration layer in Goto would inevitably be thicker than 1.50 µm. This is not found persuasive as applicant discloses at Paragraph [0090] of the instant application that as a result of a pickling process, the thickness of the C-concentrated layer can be made to fall within the range of 0 to 1.50 µm. Goto discloses a pickling process, , Para[0100]. One of ordinary skill in the art performing the pickling treatment taught by Goto under well-known conditions would necessarily produce a C-concentration layer meeting the properties of the claim invention because the pickling process taught by Goto is substantially identical to that described in the instant specification. Where the claimed and prior art products are identical or substantially identical in structure or composition, or are produced by identical or substantially identical processes, a prima facie case of either anticipation or obviousness has been established, see MPEP 2112.01.
Applicant argues that (remarks, page 7 of 9) the present inventors discovered that a thick C-concentrated layer is formed in the Zn-Ni alloy plating layer as a result of the Zn-Ni alloy plating layer being formed while a large amount of these C-originating impurities remains on the surface. The present inventors focused on this previously unrecognized C- concentrated layer and discovered that making the C-concentrated layer thinner (0 to 1.50 pm) provides the oil-well steel pipe with excellent galling resistance. Applicant argues that since Goto doesn’t teach this previously unknown C-concentrated layer, a prima facie case of obviousness has not been established. This is not found persuasive as the discovery of a previously unappreciated property of a prior art composition, or of a scientific explanation for the prior art’s functioning, does not render the old composition patentably new to the discoverer, see MPEP 2112. Even though Goto does not specifically teach the C-concentrated layer, Goto discloses a composition meeting the properties of the claim. Therefore, this composition is not patentably new.
Applicant argues that (remarks, page 7 of 9) since the prior art fails to recognize the problem associated with the C-concentrated layer, restricting the thickness of the C- concentrated layer to the claimed narrow range of 0 to 1.50 µm cannot be considered a mere routine optimization of a result-effective variable or a simple design choice. This is not found persuasive as Goto discloses pickling a product of identical chemical composition to that of the claimed composition under well-known conditions. Therefore, One of ordinary skill in the art, following the teachings of Goto, would necessarily meet the properties of the claimed invention. Products of identical chemical composition cannot have mutually exclusive properties, see MPEP 2112.01.
Therefore, the rejection is maintained.
Conclusion
THIS ACTION IS MADE FINAL. Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
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/Keith D. Hendricks/Supervisory Patent Examiner, Art Unit 1733
/JACOB BENJAMIN STILES/Examiner, Art Unit 1733
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