  United States Court of Appeals
      for the Federal Circuit
                ______________________

              SOUTHWIRE COMPANY,
                   Appellant

                           v.

   CERRO WIRE LLC, FKA CERRO WIRE, INC.,
                   Appellee
            ______________________

                      2016-2287
                ______________________

    Appeal from the United States Patent and Trademark
Office, Patent Trial and Appeal Board in No. 95/000,696.
                  ______________________

              Decided: September 8, 2017
                ______________________

   KIRK T. BRADLEY, Alston & Bird LLP, Charlotte, NC,
argued for appellant. Also represented by KEITH E.
BROYLES, Atlanta, GA; CHRISTOPHER L. MCARDLE, New
York, NY.

    PAUL RICHARD STEADMAN, DLA Piper US LLP, Chica-
go, IL, argued for appellee. Also represented by JENNIFER
E. LACROIX.
                  ______________________

    Before LOURIE, MOORE, and HUGHES, Circuit Judges.
LOURIE, Circuit Judge.
2                          SOUTHWIRE CO.   v. CERRO WIRE LLC



     Southwire Co. (“Southwire”) appeals from the decision
of the U.S. Patent and Trademark Office (“the PTO”)
Patent Trial and Appeal Board (“the Board”) in an inter
partes reexamination concluding that claims 1–42 of U.S.
Patent 7,557,301 (“the ’301 patent”) are unpatentable
under 35 U.S.C. § 103. See Cerro Wire, Inc. v. Southwire
Co., No. 2015-004351, 2015 Pat. App. LEXIS 10285
(P.T.A.B. Sept. 29, 2015) (“Final Decision”); Cerro Wire,
Inc. v. Southwire Co., No. 2015-004351, 2016 Pat. App.
LEXIS 1942 (P.T.A.B. May 2, 2016) (decision on request
for rehearing). For the reasons that follow, we affirm.
                       BACKGROUND
    Southwire owns the ’301 patent, which is directed to a
method of manufacturing an electric cable, wherein a
lubricant is incorporated into the outer sheath such that
the lubricant migrates to the surface of the sheath and
results in a reduction in pulling force required to install
the cable. See, e.g., ’301 patent Abstract. According to the
patent, one prior art solution for reducing the pulling
force on a cable during installation was a post-
manufacturing method of coating the exterior surface of
the cable with a lubricant, such as petroleum jelly, imme-
diately prior to installation. See id. col. 1 ll. 25–28.
Southwire explains that this solution was referred to as
applying “soap” to the cable, and that it was expensive
and inefficient. See, e.g., Appellant’s Br. 5–6. The ’301
patent purports to improve upon the prior art methods by
incorporating a lubricant into the cable sheath material
during manufacture, so that the finished cable sheath
comprises a lubricant that will migrate to the exterior of
the sheath and lubricate the surface during installation.
See ’301 patent col. 2 ll. 40–65.
     Claim 1 of the ’301 patent is illustrative and reads as
follows:
    1. In a method of manufacturing a finished elec-
    trical cable having a conductor core and a jacket
SOUTHWIRE CO.   v. CERRO WIRE LLC                          3



   formed primarily of a first material, the jacket
   surrounding at least said conductor core and de-
   fining the outermost exterior surface of the fin-
   ished cable, the improvement comprising
   combining a preselected lubricant with said first
   material prior to the formation of said jacket in
   order to provide a reduced coefficient of friction of
   said cable outermost exterior surface and also re-
   duce the amount of force required to pull the ca-
   ble, during its installation through building
   passageways,
       in which said lubricant is of the type
       which migrates through said jacket to be
       available at said outermost exterior sur-
       face of said finished cable during the ca-
       ble’s   installation   through    building
       passageways,
       the finished electrical cable having the
       characteristic that an amount of force re-
       quired to install said cable through corre-
       sponding holes in an arrangement of four
       2" x 4" wood blocks having holes drilled at
       15° through the broad face and the center-
       lines of the holes are offset 10" and pulled
       through at 45° to the horizontal from the
       last block is at least about a 30% reduction
       in comparison to an amount of force re-
       quired to install a non-lubricated cable of
       the same cable type and size through cor-
       responding holes in said arrangement.
’301 patent, Reexamination Certificate, col. 1 ll. 25–47
(emphases and paragraph breaks added).
     On September 14, 2012, Cerro Wire, Inc. (“Cerro”)
filed a request for inter partes reexamination of the ’301
patent. That patent had undergone two previous ex parte
4                           SOUTHWIRE CO.   v. CERRO WIRE LLC



reexaminations wherein original claims 1–21 were deter-
mined to be patentable and new claims 22–29 were added.
During the inter partes reexamination here on appeal, in
which Southwire sought to add claims 30–42, the Exam-
iner concluded that all claims, 1–42, would have been
obvious over various combinations of prior art.
    Only one combination is at issue in this appeal—U.S.
Patent 6,160,940 (“Summers”), in view of Dow Corning
Corporation, DOW CORNING® MB50-011 Masterbatch
(1997-99) (“Dow”) and Underwriters Laboratories, Inc.,
STANDARD FOR SAFETY NONMETALLIC-SHEATHED CABLES
32–34 (2000) (“UL-719”)—and Southwire disputes only
the Board’s interpretation of Summers.
     Summers describes a “fiber optic cable that is suitable
for installation in a cable passageway” and teaches that
“to reduce resistance to a cable pulling force,” the plastic
material used to form the cable “can include a friction
reducing additive” that “migrat[es] to the surface of the
cable jacket,” such as, for example, fatty acids and silicone
oils. Joint Appendix (“J.A.”) 169–70. Although Summers
does not expressly teach that the friction reducing addi-
tive can reduce the pulling force by “at least
about . . . 30%,” as required by claim 1, the Examiner
adopted Cerro’s argument that the finished cable of
Summers, in view of the other references, “has the charac-
teristic that an amount of force required to install said
cable . . . is at least a 30% reduction” because that charac-
teristic “is an inherent result of the cable being made in
accordance with the method steps.” See Final Decision,
2015 Pat. App. LEXIS 10285, at *9–10 (internal quotation
marks omitted).
    Southwire appealed to the Board, which affirmed,
concluding that the Examiner’s rejection was supported
by a preponderance of the evidence. See id. at *10–11.
The Board explained that “[w]here the claimed and prior
art products are . . . produced by identical or substantially
SOUTHWIRE CO.   v. CERRO WIRE LLC                          5



identical processes, a prima facie case of either anticipa-
tion or obviousness has been established.” Id. at *12. It
found that Summers’s lubricants “would achieve the
claimed force reduction” because Summers (in view of
Dow) teaches the same method steps—namely, extruding
a cable jacket formed from a plastic material containing a
lubricant, such that the lubricant migrates to the surface
of the jacket and lubricates the interface between the
cable and any surface of the cable passageway. Id. at *13.
The Board explained that because the claims recite “a
preselected lubricant” chosen to “provide a reduced coeffi-
cient of friction,” they “require an amount of lubricant
which meets the stated reduction in [coefficient of fric-
tion].” Id. at *16. Thus, the Board concluded, because
Summers teaches reducing the coefficient of friction using
a lubricant, it inherently teaches the 30% reduction
limitation because it renders it “obvious to have selected
[lubricant] amounts” that achieve the claimed reduction.
Id. at *16 (internal quotation marks omitted).
    The Board rejected all of Southwire’s evidence as lack-
ing factual support. The Board found that the three
declarations of Southwire’s expert, Mr. Sasse, were un-
persuasive because the data tables provided therein fail to
report standard deviations, statistical significance, or
certain relevant details of the experimental design. Id. at
*16–21. The Board found that all of Southwire’s objective
evidence lacked factual support because it contained only
“general allegation[s]” without corroborating evidence.
Id. at *24–26. Furthermore, the Board found that the
objective evidence related generally to one of Southwire’s
products (SIMpull), with no evidence that SIMpull embod-
ies the 30% reduction, or any other, claim limitation. Id.
at *25, *26, *30–34. The Board found that, while South-
wire’s evidence showed a long-felt need, it did not estab-
lish a long-felt need without solution—rather, the solution
had been provided by Summers because the need was for
a (general) alternative to the prior art use of “soap” on the
6                           SOUTHWIRE CO.   v. CERRO WIRE LLC



cables, not for a (specific) 30% reduction in pulling force
using lubricants incorporated into the sheath. Id. at *33–
36.
    Southwire timely appealed to this court. We have ju-
risdiction pursuant to 28 U.S.C. § 1295(a)(4)(A).
                        DISCUSSION
    We review the Board’s legal determinations de novo,
In re Elsner, 381 F.3d 1125, 1127 (Fed. Cir. 2004), and the
Board’s factual findings underlying those determinations
for substantial evidence, In re Gartside, 203 F.3d 1305,
1316 (Fed. Cir. 2000). A finding is supported by substan-
tial evidence if a reasonable mind might accept the evi-
dence to support the finding. Consol. Edison Co. v.
NLRB, 305 U.S. 197, 229 (1938). Obviousness is a ques-
tion of law, based on underlying factual findings, includ-
ing what a reference teaches, whether a person of
ordinary skill in the art would have been motivated to
combine references, and any relevant objective indicia of
nonobviousness. Apple Inc. v. Samsung Elecs. Co., 839
F.3d 1034, 1047–48, 1051 (Fed. Cir. 2016) (en banc).
    Southwire argues that, as an initial matter, the Board
erred in relying on “inherency” in making its obviousness
determination. Second, Southwire argues that Summers
does not inherently teach the “at least about a 30% reduc-
tion” in pulling force limitation because a limitation is not
inherent in a reference unless it is necessarily, i.e., al-
ways, present. Thus, Southwire argues, the Board’s
finding that a “skilled artisan would have had reason to
select [lubricant] concentrations that did” achieve the 30%
reduction in pulling force is the antithesis of inherency,
which requires certainty, not experimentation. Final
Decision, 2015 Pat. App. LEXIS 10285, at *21.
    Cerro responds that substantial evidence supports the
Board’s finding that any cable made with the same manu-
facturing steps as Summers (in view of Dow), using the
SOUTHWIRE CO.   v. CERRO WIRE LLC                         7



same lubricant in amounts sufficient to reduce the coeffi-
cient of friction and pulling force (as disclosed in Summers
and Dow), would also produce the same result recited in
the claims. Cerro contends that it is well-established law
that, in cases such as this one, a prima facie case for
obviousness is met where the only difference between the
claimed and prior art process is a property that results
from performing the process. Cerro argues that it is not
inventive to claim a test for cables made in accordance
with known prior art methods and discover that the cable
has that certain performance characteristic.
    First, we agree with Southwire that the Board erred
in relying on inherency in making its obviousness deter-
mination. We have held that “the use of inherency in the
context of obviousness must be carefully circumscribed
because ‘[t]hat which may be inherent is not necessarily
known’ and that which is unknown cannot be obvious.”
Honeywell Int’l v. Mexichem Amanco Holding S.A., No.
2016-1996, —F.3d—, 2017 WL 3254943, at *10 (Fed. Cir.
Aug. 1, 2017) (quoting In re Rijckaert, 9 F.3d 1531, 1534
(Fed. Cir. 1993)). While “[w]e have recognized that inher-
ency may supply a missing claim limitation in an obvi-
ousness analysis,” PAR Pharm., Inc. v. TWI Pharm., Inc.,
773 F.3d 1186, 1194–95 (Fed. Cir. 2014) (collecting cases),
we have emphasized that “the limitation at issue neces-
sarily must be present” in order to be inherently disclosed
by the reference, id. (emphasis added). The Board cited
no evidence that a reduction of 30% in the pulling force
would necessarily result from the claimed process, which
contains no steps that ensure such reduction.
     Here, the Board found that because the claims recite
“a preselected lubricant” chosen to “provide a reduced
coefficient of friction,” they “require an amount of lubri-
cant which meets the stated reduction in [coefficient of
friction].” It found that, because Summers teaches reduc-
ing the coefficient of friction using a lubricant, Summers
inherently teaches the 30% reduction limitation because
8                           SOUTHWIRE CO.   v. CERRO WIRE LLC



Summers renders it “obvious to have selected [lubricant]
amounts” that achieve that result. Final Decision, 2015
Pat. App. LEXIS 10285, at *16 (emphasis added). We
conclude that the Board erred in relying on inherency
without finding that Summers necessarily would achieve a
30% reduction in pulling force, but rather finding that it
merely renders that limitation obvious.
     However, we also conclude that the Board’s error was
harmless because, although it improperly invoked inher-
ency, it need not have. It made the necessary underlying
factual findings to support an obviousness determination.
It found that the claimed method simply applies the same
process for the same purpose as disclosed in Summers—
i.e., to reduce the pulling force on a cable for ease of
installation. See, e.g., J.A. 169.
     The Board found that Summers discloses an “identical
or substantially identical” process to that claimed in the
’301 patent. Final Decision, 2015 Pat. App. LEXIS 10285,
at *12. It found that Summers teaches that a “fiber optic
cable . . . is extruded with [a] cable jacket . . . formed from
plastic material (e.g., polyethylene) containing a lubricant
(e.g., fatty acid[] compounds, silicon oils, or fluoro-
compounds), with such lubricant characterized by migrat-
ing to the surface of [the] cable jackets . . . and lubricating
the interface between the cable jackets and virtually any
surface of or in the cable passageway.” Id. at *12–13.
Those findings are supported by substantial record evi-
dence. See, e.g., J.A. 169–70.
    None of the patented steps differs in any material way
from the process disclosed in Summers (in view of Dow).
And there is no evidence that the claimed 30% reduction
in pulling force would have been unexpected or unattain-
able from the process disclosed in Summers. In fact, there
is no evidence that the process disclosed in Summers did
not produce an “at least . . . 30% reduction” in pulling
force. Our predecessor court has held that where “all
SOUTHWIRE CO.   v. CERRO WIRE LLC                            9



process limitations . . . are expressly disclosed by [the prior
art reference], except for the functionally expressed [limi-
tation at issue],” the PTO can require an applicant “to
prove that the subject matter shown to be in the prior art
does not possess the characteristic relied on.” In re Best,
562 F.2d 1252, 1254–55 (CCPA 1977) (emphases added)
(internal quotation marks omitted). The court noted that
“[w]hether the rejection is based on ‘inherency’ under 35
U.S.C. § 102, [or] on ‘prima facie obviousness’ under 35
U.S.C. § 103, . . . the burden of proof is the same.” Id.
    Simply because Summers never quantified the reduc-
tion in pulling force achieved by its disclosed embodi-
ments does not preclude the possibility, or even
likelihood, that its process achieved at least a 30% reduc-
tion, especially since its stated purpose was the same as
that of the ’301 patent—to reduce the pulling force on the
cable for ease of installation. See, e.g., J.A. 169. In the
absence of any evidence that the claimed 30% reduction
would have been unexpected in light of the Summers
disclosure, there is no indication that the limitation is
anything other than mere quantification of the results of
a known process.
     Furthermore, the 30% reduction limitation was added
to the claim by amendment in a previous reexamination
in order to overcome the prior art, J.A. 3–4, 58–60, with
seemingly no focus on that limitation in the original
written description. Other than a single mention that,
under a certain test, “lubricated specimens” (the details of
which are undisclosed) yielded a 50% reduction in pulling
force compared to non-lubricated standards, ’301 patent
col. 6 ll. 20–24, the written description provides no discus-
sion regarding the amount of reduction in pulling force; it
merely teaches that one can reduce the pulling force by
incorporating certain lubricants into the cable sheath, as
taught by Summers. Thus, neither the patent itself nor
any evidence proffered by Southwire during the reexami-
nation provides any indication that the “at least about a
10                         SOUTHWIRE CO.   v. CERRO WIRE LLC



30% reduction” limitation was something other than an
observed result of an old process, written into the claim in
an attempt to avoid the prior art process.
    In sum, the Board’s underlying factual findings are
supported by substantial evidence and reasonably support
its conclusion that it would have been “obvious to have
selected such amounts” as would achieve the claimed
reduction in pulling force because “the claims require an
amount of lubricant which meets the stated reduction in
[coefficient of friction]” and “Summers teaches reducing
the coefficient of friction” using the same process, for the
same purpose. Final Decision, 2015 Pat. App. LEXIS
10285, at *16.
    Southwire also argues that the Board erred in ac-
knowledging that Southwire’s evidence shows a long-felt
need, but then disregarding the evidence by finding that
the prior art solved that need. Southwire argues that
such an approach is circular and would render considera-
tion of long-felt need a dead letter. Under that reasoning,
Southwire contends, every time the Board finds that a
reference teaches a limitation, there could never be a
long-felt need, as the reference purportedly already pro-
vided a solution.
    Cerro responds that the Board correctly rejected
Southwire’s objective evidence because the declarations
provided do not relate specifically to the claims at issue
and they contain no proof of a nexus to any of the claim
limitations. And, Cerro continues, the Board correctly
characterized the problem to be solved broadly, because
that characterization is supported by the ’301 patent
itself. Under that broad characterization, Cerro contends,
Summers indisputably provided several solutions before
the ’301 patent’s priority date. It taught using cable
sheaths with irregular surface characteristics, as well as
the claimed solution of lubricants incorporated into the
sheath.
SOUTHWIRE CO.   v. CERRO WIRE LLC                       11



    We agree with Cerro. Substantial evidence supports
the Board’s findings that Southwire’s evidence lacked
factual support, that its objective evidence lacked a nexus
to the claimed invention, and that any long-felt need
adduced from the evidence had already been met by
Summers. We see no legal error in its analysis.
                        CONCLUSION
    We have considered the parties’ remaining arguments
but find them to be unpersuasive. For the foregoing
reasons, we affirm the decision of the Board.
                        AFFIRMED
