Best Lock Corporation appeals from the final decision of the United States District Court for the Southern District of Indiana in which the court held that Best Lock’s U.S. Design Patent 327,636 was invalid. Best Lock Corp. v. Ilco Unican Corp., 896 F.Supp. 836, 36 USPQ2d 1527 (S.D.Ind.1995). Because the court did not clearly err in finding that the claimed design was functional and hence not ornamental, we affirm.
BACKGROUND
This case involves a design patent for a key “blade.” A typical key consists of a bow, which allows the user to turn the key in a corresponding lock, and a blade, which is the portion of the key inserted into the lock’s keyway. When a key is manufactured, the key blade is “blank,” ie., the blade has not been cut or “bitted” with the combination required to operate the corresponding lock. Although a blank key blade will not operate the lock, the profile of the key blade is manufactured to fit into the corresponding lock’s keyway. Subsequently, the blank key blade is cut to match the corresponding lock’s combination.
In the replacement key market, a locksmith or a retail store with a key duplicating facility stocks blank key blades with various key profiles. The locksmith or retailer makes a replacement key by first selecting the appropriate blank key blade. This is done by matching the key blade profile with the corresponding lock keyway. Then, the locksmith or retailer cuts the blade of the key blank with the combination required to operate the lock.
Best Lock manufactures and sells locks and keys used to maintain security at industrial, commercial, and institutional facilities. At these facilities, it is often feared that the keys used in their locks may readily be duplicated. Consequently, key and lock manufacturers, including Best Lock, have attempted to restrict unauthorized access to duplicate key blanks by obtaining utility or design patent protection on the keys. By obtaining patent protection, a company hopes to control the market for duplicate key blanks during the life of the patent.1
Best Lock is the assignee of the two patents that were at issue before the district court, U.S. Patent 5,136,869 and U.S. Design Patent 327,636. The ’869 patent, entitled “High Security Key and Cylinder Lock Assembly,” claims an improved key blade and cylinder lock assembly that provides a wider key profile than standard keys and includes other features to deter lock picking. The ’636 patent, entitled “Portion of a Key Blade Blank,” claims the ornamental design for the operative portion of a key blade blank. In addition to the ’636 design patent, Best Lock is the assignee of 33 other design patents on key blade designs. It also is the assignee of 34 design patents directed to keyways designed to mate with the key blades claimed in Best Lock’s 34 key blade design patents. The ’636 patent is the only design patent at issue on appeal.
Figures 1-5 of the ’636 design patent are shown below:
*1565[[Image here]]
Ileo manufactures duplicate and replacement key blanks for existing locks. It sells its replacement key blanks to locksmiths and replacement key retailers. In 1993, Ileo copied the design of a Best Lock key, which had a key blade shaped like the design shown in the ’636 patent. It subsequently distributed key blanks with that key blade shape at the annual convention of the Associated Locksmiths of America. In response, Best sued Ileo, alleging, inter alia, infringement of the ’636 design patent and the ’869 utility patent. Ileo counterclaimed, seeking a declaratory judgment of invalidity and nonin-fringement of both patents.
After a ten-day bench trial, the district court held that the ’869 patent claims were invalid under 35 U.S.C. § 102 because the claims were anticipated by the prior art. Best Lock Corp. v. Ilco Unican Corp., 896 F.Supp. 836, 837, 36 USPQ2d 1527, 1528 (S.D.Ind.1995). Best Lock has not appealed that holding. The court also held that the ’636 design patent was invalid. In particular, the court found that Best Lock’s key blades were not “a matter of ornamental concern to the purchaser or the user.” Id. at 843, 36 USPQ2d at 1534. The court further found that the design patent was invalid because the shape of the blank key blade was dictated by its function. Id. Best Lock ap*1566peals, challenging the district court’s decision regarding the ’636 patent.
DISCUSSION
Under 35 U.S.C. § 171, a design patent may be granted for a “new, original and ornamental design for an article of manufacture.” However, if the design claimed in a design patent is dictated solely by the function of the article of manufacture, the patent is invalid because the design is not ornamental. See Bonito Boats, Inc. v. Thunder Craft Boats, Inc., 489 U.S. 141, 148, 109 S.Ct. 971, 976, 103 L.Ed.2d 118, 9 USPQ2d 1847, 1851 (1989) (“To qualify for protection, a design must present an aesthetically pleasing appearance that is not dictated by function alone, and must satisfy the other criteria of patentability.”); see also In re Carletti, 51 C.C.P.A. 1094, 328 F.2d 1020, 1022, 140 USPQ 653, 654 (1964) (“[I]t has long been settled that when a configuration is the result of functional considerations only, the resulting design is not patentable as an ornamental design for the simple reason that it is not ‘ornamental’ — was not created for the purpose of ornamenting.”). A design is not dictated solely by its function when alternative designs for the article of manufacture are available. See L.A. Gear, Inc. v. Thom McAn Shoe Co., 988 F.2d 1117, 1123, 25 USPQ2d 1913, 1917 (Fed.Cir.), cert. denied, 510 U.S. 908, 114 S.Ct. 291, 126 L.Ed.2d 240 (1993). We review for clear error the district court’s determination that the design claimed in the ’636 patent is functional. See id. at 1124, 25 USPQ2d at 1917.
On appeal, Best Lock argues that the court erred in holding the ’636 design patent invalid as being directed solely to a functional design. As support, it asserts that although a particular key and its corresponding lock must mate to operate the lock, an unlimited number of key blade and corresponding key-way designs are available. Choice of any particular design is arbitrary. Thus, Best Lock maintains that the key blade blank may have any number of different shapes and is therefore not dictated solely by functional concerns.
We disagree. The design shown in the claim of the ’636 patent is limited to a blank key blade as shown in Figures 1-5 of the patent. Best Lock did not claim a design for the entire key.2 See 37 C.F.R. § 1.153 (1995) (The claim of a design patent “shall be in formal terms to the ornamental design for the article ... as shown, or as shown and described.”) (emphasis added). The parties do not dispute that the key blade must be designed as shown in order to perform its intended function — to fit into its corresponding lock’s keyway. An attempt to create a key blade -with a different design would necessarily fail because no alternative blank key blade would fit the corresponding lock. In fact, Best Lock admitted that no other shaped key blade would fit into the corresponding keyway, and it presented no evidence to the contrary. Therefore, we find no clear error in the court’s finding that the claimed key blade design was dictated solely by the key blade’s function. Any aesthetic appeal of the key blade design shown in the ’636 patent is the inevitable result of having a shape that is dictated solely by functional concerns.
Further, Best Lock’s assertion that a variety of possible shapes of interfaces between keys and locks exists does not compel a different result. Clearly, different interfaces between key blades and corresponding lock keyways can be designed to permit the combination to function as a lock and key set. However, Best Lock’s patent does not claim the combination of a lock and corresponding key. Instead, the claim in the ’636 design patent is limited to a key blade, which must be designed as shown in the ’636 patent in order to perform its intended function.
Moreover, the fact that Best Lock also has a design patent on the keyway that mates with the key blade shown in the ’636 patent does not alter our analysis. The existence of a separate patent on the keyway is irrelevant to the construction of the ’636 patent claim and to the ultimate determination that the claimed design is dictated solely by function. See Elmer v. ICC Fabricating, Inc., 67 F.3d 1571, 1577, 36 USPQ2d 1417, *15671421 (Fed.Cir.1995) (construing design patent as limited to the article of manufacture “as shown and described” in the patent). The validity of a patent must be evaluated based on what it claims rather than on the totality of the claims of multiple patents.
For the foregoing reasons, the district court’s finding that the claimed design is solely governed by functional concerns is not clearly erroneous. Consequently, we affirm its resulting conclusion that the ’636 patent is invalid under 35 U.S.C. § 171 for failure to satisfy the statute’s omamentality requirement.
AFFIRMED.
. Key and lock manufacturers also use other methods to restrict access to duplicate key blanks. For example, some manufacturers limit the sale of a particular type of lock and key to a single customer or particular geographic region, thereby making consumer demand for replacement keys for that particular lock design so small that replacement key manufacturers have no incentive to manufacture duplicate key blanks.
. As our predecessor court previously held, "a design for an article of manufacture may be embodied in less than all of an article of manufacture....” In re Zahn, 617 F.2d 261, 267, 204 USPQ 988, 994 (CCPA 1980).