Full-Service Bronze Foundry
Every Bronze Grade. One Foundry. Complete Documentation.
Ironbound Castings is a full-service bronze foundry pouring over 20 alloy grades using green sand, no bake molding, and 3D sand printed molds. Our craftsmen produce fine-finish castings with consistent tolerances across runs — from prototype quantities to production orders. We pour all grades in-house: no subcontracting, no schedule risk, no unknown heat sources.
For U.S. Navy and defense customers, we furnish complete material certifications, test bars, chemical analysis, and mechanical test results with every delivery. Our documentation packages meet Navy procurement requirements including NAVSEA data submittals, MIL-SPEC material compliance, and DD250 delivery packages.
General Dynamics Electric Boat visited our facility in February 2019 to present on quality standards and the critical importance of the bronze castings we supply to the Navy — recognition of our long-standing relationship as a qualified supplier to the submarine fleet.
MIL-SPEC Qualified
Full material certifications, test bars, and chemical analysis furnished with every Navy and defense delivery
20+
Alloy Grades In-House
Since 1946
Serving the U.S. Navy
Alloy Families
Bronze Alloy Families
Seven distinct bronze and copper alloy families covering every application from Navy MIL-SPEC propellers and submarine piping to industrial bearings and chemical process equipment.
Tin Bronze
Tin bronzes are the classic Navy and industrial bearing alloys. High compressive strength, excellent corrosion resistance in salt water, and reliable machinability make these the go-to choice for Navy fittings, pump casings, valve bodies, and bushings.
Leaded Tin Bronze
Leaded tin bronzes offer exceptional machinability and excellent bearing properties. The lead phase provides self-lubrication and embeddability, making these alloys the standard choice for bearings, bushings, and bearing-type castings across industrial and marine service.
Manganese Bronze
High-strength manganese bronzes deliver tensile strengths up to 110,000 PSI — making them the standard alloy for Navy and commercial propellers, rudder hardware, and heavy-duty structural castings. MIL-SPEC documentation available on all grades.
Aluminum Bronze
Aluminum bronzes combine high strength, hardness, and outstanding corrosion resistance in seawater and acidic environments. Ideal for demanding marine, industrial, and structural applications where elevated strength and resistance to wear and corrosion are critical.
Nickel Aluminum Bronze
Nickel aluminum bronzes deliver the highest strength and corrosion resistance in the aluminum bronze family. C95800 is the preferred alloy for Navy submarine seawater piping systems and is specified throughout MIL-SPEC and NAVSEA documentation — including MIL-B-17464. Full material certifications and mechanical test bars furnished with every heat.
Silicon Bronze
Silicon bronzes offer excellent corrosion resistance, good strength, and superior weldability compared to standard bronzes. Used in chemical process equipment, marine hardware, and electrical components where weld-repairability is required.
Copper Nickel Alloys
Copper nickel and Monel alloys provide outstanding resistance to seawater corrosion, biofouling, and erosion — making them the preferred choice for demanding Navy and marine piping systems, heat exchangers, and condenser components. C96400 (70/30 Cu-Ni) meets MIL-SPEC requirements for Naval seawater service, while Monel grades offer exceptional strength and corrosion immunity in aggressive environments.
Why Ironbound
Bronze Casting Advantages
20+ Bronze Grades In-House
We pour over 20 bronze and copper alloy grades — including all MIL-SPEC grades required by Navy procurement specifications — without subcontracting any heats.
Green Sand & No Bake Molding
Both green sand and no bake molding processes are available, enabling fine-finish castings from a few ounces to several hundred pounds with consistent tolerances throughout the run.
MIL-SPEC Documentation
Full material certifications, test bars, chemical analysis, and mechanical test results furnished with every order. Navy procurement documentation packages available including DD250 and NAVSEA data requirements.
Complete In-House Finishing
Pattern making, prototyping, heat treating, CNC machining, and dimensional inspection are all performed on-site. Finished, inspected castings ship on a single purchase order.
Grade Reference
All Bronze Grades Poured
Typical mechanical properties — actual properties vary by heat, section size, and casting method. Certifications furnished with every order.
Tensile
37,000
Yield
17,000
Hardness
60 HB
Tensile
110,000
Yield
62,000
Hardness
223 HB
Tensile
65,000
Yield
25,000
Hardness
130 HB
Tensile
55,000
Yield
25,000
Hardness
85 HB
Tensile
60,000
Yield
28,000
Hardness
90 HB
Tensile
66,000
Yield
32,000
Hardness
76 HB
Tensile
45,000
Yield
21,000
Hardness
70 HB
Tensile
40,000
Yield
18,000
Hardness
65 HB
Tensile
44,000
Yield
22,000
Hardness
75 HB
Tensile
40,000
Yield
20,000
Hardness
65 HB
Tensile
40,000
Yield
18,000
Hardness
65 HB
Tensile
35,000
Yield
16,000
Hardness
60 HB
Tensile
32,000
Yield
16,000
Hardness
55 HB
Tensile
35,000
Yield
16,000
Hardness
60 HB
Tensile
30,000
Yield
14,000
Hardness
55 HB
Tensile
75,000
Yield
30,000
Hardness
140 HB
Tensile
75,000
Yield
30,000
Hardness
140 HB
Tensile
85,000
Yield
35,000
Hardness
170 HB
Tensile
90,000
Yield
40,000
Hardness
195 HB
Tensile
85,000
Yield
35,000
Hardness
159 HB
Tensile
45,000
Yield
20,000
Hardness
75 HB
| Grade | Name | Tensile (PSI) | Yield (PSI) | Hardness |
|---|---|---|---|---|
| C83600 | Leaded Red Brass | 37,000 | 17,000 | 60 HB |
| C86300 | Manganese Bronze (High Strength) | 110,000 | 62,000 | 223 HB |
| C86500 | Manganese Bronze | 65,000 | 25,000 | 130 HB |
| C87200 | Silicon Bronze | 55,000 | 25,000 | 85 HB |
| C87500 | Silicon Bronze | 60,000 | 28,000 | 90 HB |
| C87600 | Silicon Bronze | 66,000 | 32,000 | 76 HB |
| C90300 | Tin Bronze | 45,000 | 21,000 | 70 HB |
| C90500 | Tin Bronze (Gun Metal) | 40,000 | 18,000 | 65 HB |
| C90700 | Tin Bronze | 44,000 | 22,000 | 75 HB |
| C92200 | Leaded Tin Bronze — Navy "M" Bronze | 40,000 | 20,000 | 65 HB |
| C92700 | Leaded Tin Bronze — Navy Bronze | 40,000 | 18,000 | 65 HB |
| C93200 | High-Leaded Tin Bronze | 35,000 | 16,000 | 60 HB |
| C93400 | High-Leaded Tin Bronze | 32,000 | 16,000 | 55 HB |
| C93700 | High-Leaded Tin Bronze | 35,000 | 16,000 | 60 HB |
| C93800 | High-Leaded Tin Bronze | 30,000 | 14,000 | 55 HB |
| C95200 | Aluminum Bronze | 75,000 | 30,000 | 140 HB |
| C95300 | Aluminum Bronze | 75,000 | 30,000 | 140 HB |
| C95400 | Aluminum Bronze | 85,000 | 35,000 | 170 HB |
| C95500 | Nickel Aluminum Bronze | 90,000 | 40,000 | 195 HB |
| C95800 | Nickel Aluminum Bronze (Navy Spec) | 85,000 | 35,000 | 159 HB |
| C96400 | 70/30 Copper Nickel | 45,000 | 20,000 | 75 HB |
Properties are typical minimums per ASTM and MIL specifications. Contact us for specific grade requirements or customer specification review.
Specifications
Technical Reference
Related Alloys
