ASTM B151/B151M is the standard specification by ASTM International covering copper-nickel-zinc (nickel silver) and copper-nickel rod and bar for general applications. The specification includes 10 UNS alloys ranging from corrosion-resistant 90/10 Cu-Ni (C70600) to decorative nickel silver grades (C75200, C77000). The latest edition is B151/B151M-20 (2020).
Zhengzhou Huitong (HT Pipe) supplies ASTM B151 / SB-151 compliant copper alloy rod and bar in all standard UNS alloys with full Mill Test Certificates (MTC) per EN 10204 3.1, chemical composition reports, and complete traceability. Available in multiple tempers (O60, H01, H04) and product forms (round, hexagonal, square, rectangular bar).
1. Standard Scope & Designation
ASTM B151/B151M covers copper-nickel-zinc (nickel silver) and copper-nickel rod and bar for general applications. The standard applies to round, hexagonal, square, and rectangular bar produced from 10 UNS alloy numbers. Two specification systems are provided: B151 (Inch-Pound) and B151M (SI/Metric).
| Attribute |
Inch-Pound (B151) |
SI / Metric (B151M) |
| Issuing Body |
ASTM International |
ASTM International |
| Unit System |
Inch-Pound (ksi) |
SI (MPa) |
| UNS Alloys |
C70600, C70620, C71500, C71520, C74500, C75200, C75700, C76400, C77000, C79200 |
Same 10 UNS alloys |
| Product Forms |
Round, Hex, Square, Rectangular Bar |
Round, Hex, Square, Rectangular Bar |
| Latest Edition |
B151/B151M-20 (2020) |
B151/B151M-20 (2020) |
| Temper System |
ASTM B601 (7 tempers) |
ASTM B601 (7 tempers) |
Scope Statement (ASTM B151-20): "This specification establishes the requirements for copper-nickel-zinc and copper-nickel rod and bar for general application produced from Copper Alloy UNS Nos. C70600, C70620, C71500, C71520, C74500, C75200, C75700, C76400, C77000, and C79200."
2. UNS Alloys Covered by ASTM B151
ASTM B151 covers 10 UNS copper alloy numbers in two categories: copper-nickel alloys for marine/corrosion applications and copper-nickel-zinc alloys (nickel silver) for decorative/hardware applications. Two low-phosphorus variants (C70620, C71520) are designated specifically for welding applications.
| UNS No. |
Common Name |
Ni Content % |
Category |
Primary Application |
| C70600 |
90/10 Cu-Ni |
9.0-11.0 |
Copper-Nickel |
Seawater piping, condensers |
| C70620 |
90/10 Cu-Ni (Weld) |
9.0-11.0 |
Copper-Nickel |
Welding-grade, low-P |
| C71500 |
70/30 Cu-Ni |
29.0-33.0 |
Copper-Nickel |
Marine, offshore, premium |
| C71520 |
70/30 Cu-Ni (Weld) |
29.0-33.0 |
Copper-Nickel |
Welding-grade, low-P |
| C74500 |
Nickel Silver 10% |
9.0-11.0 |
Nickel Silver |
Hardware, rivets, watch parts |
| C75200 |
Nickel Silver 18% |
16.5-19.5 |
Nickel Silver |
Jewelry, hollowware, trim |
| C75700 |
Nickel Silver 12% |
11.0-13.0 |
Nickel Silver |
Hardware, name plates |
| C76400 |
Nickel Silver 18% (Hi-Zn) |
16.5-19.5 |
Nickel Silver |
Musical instruments, precision |
| C77000 |
Nickel Silver 25% |
25.0-28.0 |
Nickel Silver |
Springs, watch components |
| C79200 |
Free-Cut Nickel Silver |
11.0-13.0 |
Nickel Silver |
Machined parts, free-cutting |
Note on Nickel Silver: Despite its name, nickel silver contains no actual silver. The name refers to its bright white/silver appearance. C77000 (25% Ni) has the highest nickel content and whitest color among nickel silver alloys in this standard.
3. Chemical Composition Requirements (Table 1)
Values are maximum unless shown as a range. The sum of identified elements shall be ≥99.5%. Copper or zinc may be calculated as the remainder. For welding-grade C70620 and C71520: lead ≤0.02%, phosphorus ≤0.01%.
| UNS |
Cu % |
Ni % |
Fe % |
Mn % |
Pb % |
Zn % |
Sn % |
Other % |
| C70600 |
Rem. |
9.0-11.0 |
1.0-1.8 |
0.2-1.0 |
0.05 |
0.50 |
— |
— |
| C70620 |
Rem. |
9.0-11.0 |
1.0-1.8 |
0.2-1.0 |
0.02 |
0.50 |
— |
P≤0.01 |
| C71500 |
Rem. |
29.0-33.0 |
0.4-1.0 |
1.0 |
0.05 |
0.50 |
— |
— |
| C71520 |
Rem. |
29.0-33.0 |
0.4-1.0 |
1.0 |
0.02 |
0.50 |
— |
P≤0.01 |
| C74500 |
63.5-66.5 |
9.0-11.0 |
0.25 |
0.25 |
0.10 |
Rem. |
0.10 |
Pb+Sn≤0.20 |
| C75200 |
63.5-66.5 |
16.5-19.5 |
0.25 |
0.25 |
0.10 |
Rem. |
0.10 |
Pb+Sn≤0.20 |
| C75700 |
63.5-66.5 |
11.0-13.0 |
0.25 |
0.25 |
0.10 |
Rem. |
0.10 |
Pb+Sn≤0.20 |
| C76400 |
53.5-56.5 |
16.5-19.5 |
0.25 |
0.25 |
0.10 |
Rem. |
0.10 |
Pb+Sn≤0.20 |
| C77000 |
53.5-56.5 |
25.0-28.0 |
0.25 |
0.25 |
0.10 |
Rem. |
0.10 |
Pb+Sn≤0.20 |
| C79200 |
58.0-62.0 |
11.0-13.0 |
0.25 |
0.25 |
2.5-3.5 |
Rem. |
0.10 |
Free-cut |
Key Notes: "Rem." = remainder (copper or zinc calculated as remainder to reach 100%). C70620/C71520 are welding-grade variants with Pb ≤0.02% and P ≤0.01%. C79200 is free-machining with 2.5-3.5% lead — highest machinability in this standard.
4. Mechanical Property Requirements (Tables 3-6)
Mechanical properties vary by alloy, temper, and product form. Copper-nickel alloys (C70600-C71520) require tensile strength, yield strength (0.5% extension), and elongation. Nickel silver alloys (C74500-C79200) primarily use tensile strength as acceptance criterion per temper.
| UNS / Alloy |
Temper |
Tensile min (MPa) |
Yield min (MPa) |
Elong. % |
Notes |
| C70600 / C70620 (90/10 Cu-Ni) |
O60 (Ann.) |
275 |
105 |
30 |
Soft annealed |
| M30 (HW) |
310 |
205 |
15 |
Hot worked |
| H04 (Full Hard) |
380 |
310 |
5 |
Maximum strength |
| C71500 / C71520 (70/30 Cu-Ni) |
O60 (Ann.) |
380 |
155 |
30 |
Soft annealed |
| M30 (HW) |
415 |
310 |
15 |
Hot worked |
| H04 (Full Hard) |
485 |
380 |
5 |
Maximum strength |
| Nickel Silver (H04) |
C75200/C77000 |
550-690 |
— |
— |
Tensile only |
| C79200 (H02) |
450-550 |
310-415 |
10-20 |
Free-cut machinability |
Testing Standard: Mechanical testing per ASTM B249/B249M. Yield strength determined by 0.5% extension under load method. Elongation measured on 4D gauge length (or 2 in / 50 mm for sheet/strip).
5. Temper Conditions (ASTM B601 — 7 Tempers)
ASTM B151 specifies 7 standard temper conditions per ASTM B601. Grain size requirements (OS tempers) apply only to nickel silver alloys C74500, C75200, C75700, C76400, C77000, and C79200.
| Temper Code |
Description |
Grain Size (mm) |
Applicable Alloys |
| O60 |
Soft Annealed |
Not specified |
All alloys |
| OS015 |
Grain Size Annealed |
0.015-0.030 |
Ni Silver only |
| OS035 |
Grain Size Annealed |
0.025-0.050 |
Ni Silver only |
| OS070 |
Grain Size Annealed |
0.050-0.100 |
Ni Silver only |
| M30 |
Hot Worked |
— |
All alloys |
| H01 |
Cold Worked 1/4 Hard |
— |
All alloys |
| H04 |
Cold Worked Full Hard |
— |
All alloys |
6. Grain Size Requirements for OS Tempers
For nickel silver alloys (C74500, C75200, C75700, C76400, C77000, C79200) in OS tempers, the annealed grain size shall meet the following requirements when specified in the purchase order. Grain size is measured per ASTM E112.
| Temper |
Grain Size Range (mm) |
Application Guidance |
| OS015 |
0.015 - 0.030 |
Fine grain for best strength + ductility |
| OS035 |
0.025 - 0.050 |
Standard annealed grain size |
| OS070 |
0.050 - 0.100 |
Coarse grain for deep drawing |
Note: Grain size requirements apply only to nickel silver alloys (C74500, C75200, C75700, C76400, C77000, C79200) in OS tempers. Copper-nickel alloys (C70600, C70620, C71500, C71520) do not have specified grain size requirements under this standard.
7. Testing & Inspection Requirements
| Test / Inspection |
Requirement |
Standard |
| Chemical Analysis (Heat) |
One per lot; all elements per Table 1 limits |
ASTM E478 |
| Tensile Test |
One per lot; tensile, yield, elongation |
ASTM B249 |
| Grain Size (OS tempers) |
Per OS temper specification |
ASTM E112 |
| Hardness (if required) |
Per purchase order requirements |
ASTM E18 / E10 |
| Dimensional Verification |
Diameter/thickness, length, straightness |
ASTM B249 Tables |
| Surface Condition |
Free from seams, cracks, harmful defects |
Visual inspection |
8. Product Forms & Dimensional Tolerances
ASTM B151 applies to rod and bar in the following forms. Dimensional tolerances per ASTM B249/B249M tables. Product forms shall be designated in the purchase order.
| Product Form |
Typical Size Range |
Tolerance Standard |
| Round Bar |
1/4" to 4" diameter |
ASTM B249 Table 2 |
| Hexagonal Bar |
1/4" to 3" across flats |
ASTM B249 Table 2 |
| Square Bar |
1/4" to 4" sides |
ASTM B249 Table 9 |
| Rectangular Bar |
Width 1/4" to 12", Thickness per spec |
ASTM B249 Table 11 |
| Tolerance Type |
Inch-Pound (B151) |
SI (B151M) |
| Diameter/Thickness |
Per B249 Table 2/9/11 |
Per B249M equivalents |
| Length |
Per B249 Table 13/15 |
Per B249M equivalents |
| Straightness |
Max 0.010 in/ft camber |
Max 0.83 mm/m camber |
9. Related Standards & Companion Specifications
| Standard |
Scope |
Relationship to B151 |
| ASTM B601 |
Temper designation system for metals |
Defines all 7 temper codes |
| ASTM B249/B249M |
General requirements for rod, bar, shapes |
Dimensional tolerances, testing |
| ASTM B478 |
Chemical analysis of copper alloys |
Composition verification |
| ASTM E112 |
Grain size measurement |
OS temper grain verification |
| ASTM B122/B122M |
Copper-nickel-zinc nickel silver sheet/strip |
Related Ni Silver product form |
| ASTM B111/B111M |
Copper-nickel seamless tube |
Related Cu-Ni product form |
| ASTM B453/B453M |
Copper-zinc-lead alloy rod (free-cut) |
C79200 free-cut reference |
| ASME SB-151 |
ASME Boiler & Pressure Vessel Code |
Code adoption of ASTM B151 |
10. B151 vs B122 vs B111 — Copper-Nickel and Nickel Silver Specifications Compared
| Criteria |
ASTM B151 |
ASTM B122 |
ASTM B111 |
| Product Form |
Rod & Bar |
Sheet, Strip, Plate |
Seamless Tube |
| Alloys |
10 UNS (Cu-Ni + Ni Silver) |
Ni Silver (C74500-C76400) |
Cu-Ni (C70600, C71500) |
| Tempers |
O60, OS, M30, H01, H04 |
O61, H01, H02, H04, H06, H08 |
O61, H55, H80 |
| Grain Size Req. |
Yes (OS tempers) |
Yes |
Yes (0.010-0.045mm) |
| Yield Strength |
Required (Cu-Ni only) |
Not required |
Required |
| Primary Use |
General bar stock |
Sheet/strip forming |
Seawater piping |
Selection Guide: Choose B151 rod/bar for machined parts, structural bar, and general applications. Choose B122 sheet/strip for formed components, decorative trim, and architectural applications. Choose B111 tube for seawater piping, condensers, and heat exchangers.
11. How to Order — Required Information
| No. |
Item |
Requirement / Example |
| 1 |
Specification |
ASTM B151 or ASME SB-151 |
| 2 |
UNS Alloy |
e.g., C70600 (90/10 Cu-Ni), C71500 (70/30 Cu-Ni), C75200 (18% Ni Silver) |
| 3 |
Temper |
O60 (soft annealed), H01 (1/4 hard), H04 (full hard), or OS035 (grain size) |
| 4 |
Product Form |
Round Bar, Hexagonal Bar, Square Bar, Rectangular Bar |
| 5 |
Dimensions |
Diameter or across-flats: e.g., 1" round, 2" hex, 1" x 3" rectangle |
| 6 |
Length |
Random lengths or specific cut lengths with tolerance |
| 7 |
Grain Size (if OS) |
OS015, OS035, or OS070 for nickel silver alloys only |
| 8 |
Quantity |
Weight (lbs/kg) or piece count with tolerance |
| 9 |
Certification |
EN 10204 3.1 MTC with chemical and mechanical test reports |
Download ASTM B151 / B151M Standard (PDF)
The official ASTM B151/B151M-20 (2020) PDF is available from our HT Pipe Download Center. The document includes full chemical composition Table 1 for all 10 UNS alloys, mechanical property Tables 3-6 by temper, grain size requirements for OS tempers, dimensional tolerance references to ASTM B249/B249M, and supplementary requirements.
Go to Download Center | Request MTC / Quotation
12. Frequently Asked Questions
Q: What is the difference between C70600 and C70620 copper-nickel?
C70620 is a welding-grade variant of C70600 with stricter impurity controls: lead ≤0.02% (vs 0.05% for C70600) and phosphorus ≤0.01% (vs 0.02% for C70600). These tighter limits ensure optimal weldability and prevent weld defects. Choose C70620 when the rod will be welded; choose C70600 for general corrosion-resistant applications.
Q: What is nickel silver and does it contain real silver?
Nickel silver (also called German silver) is an alloy of copper, nickel, and zinc. Despite its name, it contains no actual silver. The name refers to its bright white/silver appearance. ASTM B151 covers nickel silver alloys C74500 through C79200, with C77000 (25% Ni) having the whitest color and C79200 being free-machining with added lead.
Q: What are the properties of 70/30 copper-nickel (C71500) vs 90/10 (C70600)?
C71500 (70/30 Cu-Ni) has higher nickel content (29-33% vs 9-11%) providing superior corrosion resistance, especially in polluted seawater and high-velocity conditions. Mechanically, C71500 is stronger: O60 annealed tensile 380 MPa min vs 275 MPa min for C70600. C71500 also has higher yield strength (155 vs 105 MPa). Choose C71500 for premium marine applications, offshore platforms, and high-performance condensers.
Q: Why do some nickel silver alloys require grain size specification (OS tempers)?
For nickel silver alloys in OS tempers, the grain size directly affects formability and appearance. Finer grains (OS015: 0.015-0.030mm) provide best strength and ductility balance. Coarser grains (OS070: 0.050-0.100mm) offer better deep-drawing performance with less surface galling. Specify OS035 for general annealed applications where neither extreme is required.
Q: What is the machinability of C79200 free-cutting nickel silver?
C79200 (free-cutting nickel silver) has a machinability rating of approximately 80% relative to free-machining brass (UNS C36000). It contains 2.5-3.5% lead which acts as a chip breaker during machining, enabling high-speed CNC operations with excellent surface finish. In H02 temper, C79200 achieves tensile strength 450-550 MPa with yield strength 310-415 MPa — ideal for precision machined components.
Q: Can ASTM B151 nickel silver be used for jewelry applications?
Yes. ASTM B151 nickel silver alloys — particularly C75200 (18% Ni) and C77000 (25% Ni) — are widely used in jewelry, hollowware, and decorative hardware. C77000 has the highest nickel content (25-28%) providing the whitest, most silver-like appearance. These alloys can be polished to a high luster and are hypoallergenic compared to base metals. For jewelry applications, specify O60 or OS035 temper for best workability.
Request a Quote — ASTM B151 Copper Alloy Rod & Bar
Zhengzhou Huitong (HT Pipe) supplies ASTM B151 / SB-151 compliant copper alloy rod and bar in all standard UNS alloys (C70600, C71500, C75200, C77000, C79200) with full EN 10204 3.1 Mill Test Certificates. Available in multiple tempers and product forms with competitive pricing and reliable delivery.
