DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Response to Amendment
This office action is responsive to the amendment filed on 08 July 2026. As directed by the amendment: claims 6 & 10 have been amended, claims 1-5, 7, 11, 12, 14 & 15 have been cancelled, and claims 16-21 have been added. Thus, claims 6, 8-10, 13 & 16-21 are presently pending in this application.
Claim Objections
Claims 18 & 20 are objected to because of the following informalities:
Claims 18 & 20, lines 1-2: “…is an austenitic stainless steel consists of…” appears it should read “…is an austenitic stainless steel consisting of…”
Appropriate correction is required.
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claims 6, 8-10, 13, 16 & 21 are rejected under 35 U.S.C. 103 as being unpatentable over Ogawa (US 2003/0196734 A1) in view of Momozono et al. (US 2015/0194227 A1; hereafter Momozono), Frobose et al. (US 2018/0223388 A1; hereafter Frobose), Makino et al. (US 2023/0140650 A1; hereafter Makino) and Guhrs et al. (US 2018/0209005 A1; hereafter Guhrs).
Regarding claim 6, Ogawa discloses a method of manufacturing a tube (see abstract; para 24; claim 1, etc.) of a stainless steel (see para. 21, 30, claim 7, etc.), comprising the steps of:
providing a hollow (i.e., “a tubing material for the seamless steel tube” initially formed by a hot working process), the hollow comprising an outer wall surface, an inner wall surface, an outer diameter, an inner diameter, a wall thickness defined by a half of a difference between the outer diameter and the inner diameter, and an axial length (i.e., a “hollow cylindrical shape”; see para. 3),
cold working of the hollow into a tubular intermediate product in a first working step (see “cold drawing” before the heat treatment in para. 24; see also para. 33), wherein in the first working step the hollow undergoes a first reduction in wall thickness and a first reduction in outer diameter (see paras. 33-37; table 4, etc.),
annealing of the tubular intermediate product (see paras. 24, 33, 35; see also paras. 18-22); and
cold pilger rolling the tubular intermediate product into the tube in a second working step (see “cold rolling” after the heat treatment in para. 24; “cold rolling” via “cold pilger mill” in paras. 37-38), wherein in the second working step the tubular intermediate product undergoes a second reduction in wall thickness and a second reduction in outer diameter (see para. 37-38; table 4, etc.).
Ogawa does not disclose the first working step to be cold pilger rolling (Ogawa suggests cold drawing), or the additional limitations wherein the first reduction in wall thickness is larger than the second reduction in wall thickness and the first reduction in outer diameter is larger than the second reduction in outer diameter; wherein a wall thickness of the tube is equal to or larger than an inner diameter of the tube; wherein an axial length of the tube is 12 m or more; wherein a tensile strength Rm of the tube is 850 N/mm2 or more; an wherein a mean roughness index Ra of an inner wall surface of the tube is 0.8 μm or less.
With respect to the limitation wherein the first working step is cold pilger rolling, Ogawa discloses this process to be used for the second working step but uses cold drawing for the first working step. Nevertheless, Ogawa explains that cold pilger rolling is capable of providing a higher rate of reduction compared to cold drawing (para. 38).
Momozono teaches a method of manufacturing a tube of stainless steel (e.g., austenitic stainless steel) comprising providing a hollow (e.g., a tube formed by a hot extrusion molding method; see para. 101, lines 1-5), cold pilger rolling the hollow into a tubular intermediate product in a first working step (see para. 101, lines 5-9), wherein in the first working step the hollow undergoes a first reduction in wall thickness and a first reduction in outer diameter (i.e., so as to cause a reduction of area of at least 65% [para. 92]; e.g., 60-91% [para. 101], annealing the tubular intermediate product (para. 102, lines 1-3; see also para. 92 & 92), and cold working (e.g., cold drawing) the tubular intermediate product into the tube in a second working step, wherein the tubular intermediate product undergoes a second reduction in area (e.g., less than or equal to 50% [see paras. 92 & 94]; an area reduction of 27%-55% in para. 102),
wherein the first reduction in area is larger than the second reduction in area (e.g., 65% or greater vs less than or equal to 50%; see pars. 92-94).
Momozono explains that the greater area reduction of the first working step, together with the annealing step, may be used to improve the crystal orientation on the surface of the tube (para. 92-93). By contrast, the second working step should have a smaller reduction in area to “improve the dimensional accuracy of the…tube and to perform thinning” (para. 94).
Guhrs also teaches a method of manufacturing a tube of stainless steel (e.g., austenitic stainless steel) comprising providing a tubular hollow (step 1; para. 55), cold pilger roller the hollow into a tube (step 2; para. 56), annealing the tube (step 5), before performing further cold forming (step 6). In para. 56, Guhrs suggests that the second “cold working” step may be “e.g. by cold drawing”, but Guhrs explains that “cold forming” may be seen to encompass various methods including cold pilger milling or cold drawing (para. 11-12), whereby the hollow is “formed into a tube with a defined, reduced outer diameter and a defined wall thickness or wall strength”. Thus, Guhrs may be seen to teach that the second cold working step may be cold drawing or cold pilger rolling.
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify the method of Ogawa such that the step of cold working of the hollow into a tubular intermediate product comprises cold pilger working of the hollow into the tubular intermediate product, in view of the teachings of Momozono and/or Guhrs, as the simple substitution of one known method of cold forming a hollow into a tubular intermediate product (i.e., cold drawing, as originally recited in Ogawa) for another (i.e., cold pilger rolling, as in Momozono and Guhrs) to obtain predictable results (e.g., enabling a higher rate of reduction vs cold drawing; enabling the diameter and wall thickness to be simultaneously reduced, etc.).
It would have been further obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify the method of Ogawa such that the first reduction in wall thickness is larger than the second reduction in wall thickness and the first reduction in outer diameter is larger than the second reduction in outer diameter (i.e., such that the first area reduction during the first cold rolling step is larger than the second area reduction during the second cold rolling step), in view of the teachings of Momozono, as the use of a known technique (i.e., providing a relatively high reduction in area during a first working step [e.g., 65% or greater] and a relatively low reduction in area during a second working step [e.g., 50% or less], as in Momozono) to improve a similar method (the method of Ogawa, as otherwise modified above) in the same way (e.g., providing for a first working step which, together with the intermediate annealing, generates a desired microstructure, whereby a smaller second working step serves to improve dimensional accuracy and further refine the microstructure [rather than completely reworking it]).
Regarding the limitation wherein a wall thickness of the tube is equal to or larger than an inner diameter of the tube, Frobose teaches (para. 34) that “thick-walled tubes are required in the high-pressure technique for fluid guidance”, and that “[t]ubes in which the inner diameter is half the outer diameter or less, preferably one third of the outer diameter of less, are considered to be high-pressure resistant…” (see also para. 35). As can be readily calculated, the wall thickness would be equal to or larger than the inner diameter when the inner diameter is one third of the outer diameter or less.
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify the method of Ogawa such that the wall thickness of the tube is equal to or larger than an inner diameter of the tube (i.e., such that the inner diameter is one-third or less of the outer diameter), in view of the teachings of Frobose, to produce a high-pressure resistant “thick-walled tube” as may be required for guiding high-pressure fluids (i.e., as suggested by Frobose).
Regarding the limitation wherein the axial length is 12 m or more, Guhrs further teaches that a steel tube (e.g., an austenitic stainless steel tube; which may be formed by cold pilger milling or cold drawing [para. 11]) may have lengths of “at least 6 m, for example, of at least 12 m and/or of at least 100 m” (para. 30). Guhrs explains that certain applications, such as off-shore sea water environments and/or for guiding aggressive media, require shipping in such lengths (paras. 4-7), e.g. in a coiled arrangement (para. 23).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify the method of Ogawa such that an axial length of the tube is 12 m or more (e.g., 100 m or more), in view of the teachings of Guhrs, as Guhrs explicitly suggests that such tubes may be provided in lengths of, for example 12 m or more or even 100 m or more, as is otherwise known to be required for particular applications.
Regarding the limitation wherein a tensile strength Rm is 850 N/mm2 or more, Makino teaches that a steel tube (pipe), which may have a wall thickness equal to or larger than the inner diameter (see para. 45: D/d is “more preferably 2.0 or more”; see also paras. 76-79, wherein D/d may be > 3.0) may have “mechanical properties…selected according to the usage” of the tube and, when used as pressure piping, may have a tensile strength of “preferably 500 MPa or more…, more preferably 800 MPa or more, and…still more preferably 900 MPa or more” (para. 50; 1 MPa = 1 N/mm2).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify the method of Ogawa such that a tensile strength Rm of the tube is 850 N/mm2 or more, in view of the teachings of Makino, as Makino explains that such tubes may have mechanical properties selected according to the required usage and, when used as pressure piping (e.g., high-pressure piping, as otherwise suggested by Frobose), such a tube may have a tensile strength of, e.g., 800 MPa or more (encompassing the claimed range) or 900 MPa or more (within the claimed range), etc.
Examination Note: to promote compact prosecution, it is noted that Frobose teaches a stainless steel tube may have an elastic limit (Rp0.2) of 812 N/mm2 (para. 43), and one of ordinary skill in the art would reasonably expect a corresponding tensile strength to be 850 N/mm2 or more. It is also noted that instant claim 16 requires an elastic limit Rp0.2 of 750 N/mm2 or more. As the elastic limit of Frobose is higher than the elastic limit of claim 16 here, the corresponding tensile strength would also reasonably be higher.
Regarding the limitation wherein a mean roughness index Ra of an inner wall surface of the tube is 0.8 μm or less, Makino further teaches that inner wall surfaces of such tubes may be polished to have a mean roughness index Ra of 0.2 μm or less (para. 87).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify the method of Ogawa such that a mean roughness index Ra of the inner wall surface of the tube is 0.8 μm or less (e.g. 0.2 μm or less), in view of the teachings of Makino, e.g., to ensure desired flow performance, to enhance corrosion resistance, and/or to meet required sanitary standards, as is otherwise well known in the art.
Examination Note: to promote compact prosecution, it is noted that certain regulations and industry standards require tubing to meet inner wall surface finish requirements. By way of example, “Bio-Processing Equipment” by Hygienic Stainless Steels Ltd., cited in the PTO-892 provided with this action, explains that the interior surfaces of tubes may meet an SF1 surface designation of ASME BPE-2016, as drawn or polished, with an Ra of 0.51 μm max, or an SF4 designation via mechanical polishing and/or electropolishing, with an Ra of 0.38 μm max.
Regarding claim 8, with respect to the limitation wherein the hollow comprises an axial length of 12 m or less, as would be understood by a person having ordinary skill in the art, when a tube is formed by cold pilger milling, the initial blank (hollow) is worked so as to reduce the outer diameter and wall thickness, which results in the tube having a longer axial length (often significantly longer length) than the initial blank (hollow)(see also Guhrs, paras. 13-17, describing cold pilger milling).
As described for claim 6 above, Guhrs teaches that a steel tube (e.g., a stainless steel tube), formed from a blank by cold working (e.g., cold pilger milling or cold drawing [para. 11]) may have lengths of “for example, of at least 12 m and/or of at least 100 m” (para. 30).
When the method of Ogawa is modified in view of Guhrs (i.e., as set forth for claim 6 above), at least when the axial length of the tube is selected to be at or near the lower end of the range (e.g., 12 m), the hollow from which the tube is formed would reasonably comprise an axial length of 12 m or less.
Regarding claim 9, with respect to the limitation wherein the tube is coiled after the second working step, Guhrs further teaches that coiling a tube is required in order to allow shipping / transport of finished tubes with lengths over 6 m to a location of use (para. 23, lines 9-16; see also, e.g., para. 34).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify the method of Ogawa such that the tube is coiled after the second working step (i.e., after being formed to the desired final dimensions), in view of the teachings of Guhrs, to allow the finished tube to be shipped or otherwise transported for use at another location (i.e., as suggested by Guhrs).
Regarding claim 10, with respect to the limitation wherein the tube is not annealed after the second working step and before the coiling step, Guhrs further explains that, while prior art techniques typically employ a heat treatment / annealing step after cold forming, they have found that the effect of such annealing is largely nullified by the subsequent coiling or winding step (para. 23).
As such, Guhrs suggests that the coiling step should be performed first, whereby such annealing / heat treatment is only performed after the coiling step (para. 24).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify the method of Ogawa such that the tube is not annealed after the second working step and before the coiling step, in view of the teachings of Guhrs, as Guhrs explains that the effect of such annealing would be largely nullified anyway by the subsequent coiling step and, if required, the tube can be annealed after coiling.
Regarding claim 13, the method of Ogawa, as modified above, reads on or otherwise renders obvious the additional limitation wherein the axial length of the tube is 100 m or more.
In particular, as noted for claim 6 above, Guhrs explicitly teaches that such a tube may be manufactured to have a length of at least 100 m.
Regarding claim 16, with respect to the limitation wherein an elastic limit (Rp0.2) of the tube is 750 N/mm2 or more, as explained for claim 6 above, Frobose teaches a stainless steel tube may have an elastic limit (Rp0.2) of 812 N/mm2 (para. 43).
As also explained for claim 6, with respect to the tensile strength limitation, Makino teaches that a steel tube (pipe) may have “mechanical properties…selected according to the usage” of the tube.
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify the method of Ogawa such that the elastic limit (Rp0.2) of the tube (which has a tensile strength Rm of 850 N/mm2 or more, as required for claim 6) is 750 N/mm2 or more, in view of the teachings of Frobose and/or Makino, as Makino explains that such tubes may have mechanical properties selected according to the required usage and, Frobose otherwise teaches that a stainless steel tube may have an elastic limit (Rp0.2) of greater than 750 N/mm2 (i.e., 812 N/mm2).
Regarding claim 21, the method of Ogawa, as modified above, reads on or otherwise renders obvious the additional limitation wherein the stainless steel has a nickel content of 1 to 25 weight percent.
In the original disclosure, Ogawa discloses examples of suitable stainless steels (e.g., table 5, types C-E), wherein example type C has a nickel content of 24.44, falling within the range of 1 to 25 weight percent.
To promote compact prosecution, it is also noted that Guhrs teaches an austenitic stainless steel (i.e., a UNS S31254 steel) suitable for cold-forming into a tube which comprises a nickel content of 17.82 wt.% (paras. 50 & 55). Guhrs explains that UNS S31254 steel is a grade of steel established by ASME for use in boilers and high pressure vessels (para. 50).
If not already seen as such, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify the method of Ogawa to utilize such a UNS S31254 steel (whereby the stainless steel has a nickel content of 17.82 wt.%, within the claimed range of 1 to 25 weight percent), in view of the teachings of Guhrs, especially considering that it has been held to be within the general skill of a worker in the art to select a known material on the basis of its suitability for the intended use as a matter of obvious design choice. In re Leshin, 125 USPQ 416.
Claims 17 & 18 are rejected under 35 U.S.C. 103 as being unpatentable over Ogawa in view of Momozono, Frobose, Makino and Guhrs as applied to claim 6 above, and further in view of Hedvall et al. (WO 2019/053035 A1; hereafter Hedvall).
Regarding claims 17 & 18, Guhrs further teaches that austenitic stainless steels may be used to form tubes, and are known for “good stiffness” and “good corrosion resistance” (para. 20).
Hedvall teaches an austenitic stainless steel composition (in particular, a 21-6-9 / UNS S21900 steel) suitable for forming into a tube by cold forming, including cold pilger milling (see pg. 4, lines 20-25, pg. 4, lines 29-32; pg. 5, lines 4-8; etc.), the austenitic stainless steel comprising (pg. 4, lines 20-25) / consisting of (pg. 4, lines 29-32), in weight percent:
C up to 0.080 (“C≤ 0.080”),
Si up to 1.00 (“Si ≤ 1.00”),
Mn in a range from 8.00 to 10.00 (“8.00 ≤ Mn ≤ 10.00”),
P up to 0.030 (“P ≤ 0.030”),
S up to 0.030 (“S ≤ 0.030”),
Cr in a range from 19.00 to 21.50 (“19.00 ≤ Cr ≤ 21.50”),
Ni in a range from 5.50 to 7.50 (“5.50 ≤ Ni ≤ 7.50”),
Mo up to 0.75 (“Mo ≤ 0.75”),
Cu up to 0.75 (“Cu ≤ 0.75”),
N in a range from 0.15 to 0.40 (“0.15 ≤ N ≤ 0.40”) and
with a residual Fe and unavoidable impurities (“balance Fe and normally occurring impurities”).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify the method of Ogawa (as otherwise modified above) to utilize an austenitic stainless steel having the above composition, in view of the teachings of Hedvall, especially considering that it has been held to be within the general skill of a worker in the art to select a known material on the basis of its suitability for the intended use as a matter of obvious design choice. In re Leshin, 125 USPQ 416.
Claims 19 & 20 are rejected under 35 U.S.C. 103 as being unpatentable over Ogawa in view of Momozono, Frobose, Makino and Guhrs as applied to claim 6 above, and further in view of Timken et al. (US 2016/0067668 A1; hereafter Timken).
Regarding claims 19 & 20, Guhrs further teaches that austenitic stainless steels may be used to form tubes, and are known for “good stiffness” and “good corrosion resistance” (para. 20).
Timken provides examples of various alloys that may be suitably used for certain industrial applications, including for use as a conduit (including pipes and tubes), in hydrocarbon conversion applications (see para. 17 & 20). Table 2, in particular, teaches “austenitic stainless steel chemical composition ranges (all values in weight percent)”.
Among the listed austenitic stainless steel compositions is 316L / UNS S31603, disclosed to comprise / consist of, in weight percent:
C up to 0.040 (“0.03 max”),
Mn up to 2.00 (“2.0 max”),
Si up to 1.00 (not specifically listed; likely due to typo / accidental duplication of S column in the table; however, published 316L / UNS S31603 standards dictate Si content to be ≤ 1.00),
Cr in a range from 16.00 to 19.00 (“16-18”),
Ni in a range from 10.00 to 14.00 (“10-14”),
Mo in a range from 2.00 to 3.00 (“2-3”),
Cu up to 0.80 (“—“, i.e., none),
P up to 0.050 (“0.045 max”),
S up to 0.030 (“0.03 max”),
N up to 0.20 (“0.1 max”) and
with a residual of Fe (“Bal: 62-72”) and unavoidable impurities.
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify the method of Ogawa (as otherwise modified above) to utilize an austenitic stainless steel having the above composition, in view of the teachings of Timken (or Timken and Guhrs), especially considering that it has been held to be within the general skill of a worker in the art to select a known material on the basis of its suitability for the intended use as a matter of obvious design choice. In re Leshin, 125 USPQ 416.
Response to Arguments
Applicant's arguments filed 08 July 2026 have been fully considered.
With respect to applicant’s argument that Fonte discloses heat treatment as a “post-processing” step rather than an intermediate step after the first reduction, this argument is not found to be persuasive. In context, the term “post-processing” would have been understood to mean a step performed after the previous forming process, not necessarily after the completion of all forming processes. Furthermore, Fonte explicitly teaches that, when two or more forming passes are used, the first pass is preferably larger than the second and that annealing may relieve stresses / restore ductility after one or more forming passes, prior to one or more additional forming passes. Applicant’s argument that the heat treatment of Fonte would “induce one of ordinary skill in the art to conduct any second flowforming step under the same forming conditions as an initial flowforming step” is not found to be persuasive as it ignores Fonte’s related disclosure that a first flowforming step should be larger.
However, to promote compact prosecution, the new or otherwise amended grounds of rejection applied to the amended claims in this action incorporate alternative teachings which provide additional motivation for a first reduction to be larger than a second reduction.
Conclusion
The prior art made of record in the attached PTO-892 and not relied upon is considered pertinent to applicant's disclosure.
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). 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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/Richard K. Durden/Examiner, Art Unit 3753
/ROBERT K ARUNDALE/Primary Examiner, Art Unit 3753
Prosecution Insights