Replicating Bronze Hardware

Technical Procedures Disclaimer

Prior to inclusion in GSA’s library of procedures, documents are reviewed by one or more qualified preservation specialists for general consistency with the Secretary of Interior Standards for rehabilitating historic buildings as understood at the time the procedure is added to the library. All specifications require project-specific editing and professional judgement regarding the applicability of a procedure to a particular building, project or location. References to products and suppliers are to serve as a general guideline and do not constitute a federal endorsement or determination that a product or method is the best or most current alternative, remains available, or is compliant with current environmental regulations and safety standards. The library of procedures is intended to serve as a resource, not a substitute, for specification development by a qualified preservation professional.


We’ve reviewed these procedures for general consistency with federal standards for rehabilitating historic buildings and provide them only as a reference. Specifications should only be applied under the guidance of a qualified preservation professional who can assess the applicability of a procedure to a particular building, project or location. References to products and suppliers serve as general guidelines and do not constitute a federal endorsement nor a determination that a product or method is the best alternative or compliant with current environmental regulations and safety standards.




A. This procedure includes guidance on replicating missing
or irreparably damaged bronze hardware at historic
buildings. The Contractor will fabricate custom castings
by making molds from existing, original pieces, or when
no original exists, from original drawings or photographs.
The more detailed the documentation, the better.

B. To get an estimate for replication, provide the
fabricator with close-up photographs and/or drawings
showing front and side views of the element(s), exact
dimensions, and any complex detailing. Ideally, a 35mm
camera, macro lens, and slow exposure should be used.
Architect/Engineering firms can be contacted to provide
photographs if your office does not have the needed
equipment. Provide a list of the quantity of each element
needed, since it will determine the unit cost.

C. See 01100-07-S for general project guidelines to be
reviewed along with this procedure. These guidelines
cover the following sections:

1. Safety Precautions

2. Historic Structures Precautions

3. Submittals

4. Quality Assurance

5. Delivery, Storage and Handling

6. Project/Site Conditions

7. Sequencing and Scheduling

8. General Protection (Surface and Surrounding)

These guidelines should be reviewed prior to performing
this procedure and should be followed, when applicable,
along with recommendations from the Regional Historic
Preservation Officer (RHPO).


A. Samples: Submit one sample of each unique casting for
approval by Contracting Officer's representative prior to
proceeding with fabrication remaining elements listed in
scope of work.



A. Ball and Ball

D. Conant Metal & Light

E. Brian F. Leo

(Also provides custom castings in aluminum, steel and other alloys)



A. Design Requirements: Replace missing hardware with
replicas to match originals. Design(s) to be taken from:

1. Existing original hardware.

2. Original construction drawings.

3. Photographs of original hardware.

B. New elements must match originals in all respects,
including form, material, finish, and fineness of detail.
Use the casting and finishing methods which produce the
highest quality of detail. Sand casting is acceptable for
large, flat elements such as exterior grilles. Lost wax
casting (also known as 'investment' casting or 'ceramic
shell' casting) is required for finely detailed
ornamental hardware.

C. The artisan is responsible for shrink factoring so that
the replacement element matches the dimensions of the

D. If no original elements exist, and original drawings or
specifications indicating the originally intended finish
are not available, fabricate new hardware to match the
original finish (color, texture, sheen) of other original
hardware in the building.