ASTM B196
Standard Specification for Copper-Beryllium Alloy Rod and Bar
Specification for copper-beryllium alloy (C17000, C17200, C17300, C17500, C17510) rod and bar in solution-annealed, cold-drawn, age-hardened and mill-hardened tempers, with age-hardening capability requirements.
What ASTM B196 specifies
ASTM B196 is the rod-and-bar companion of B194 and the specification most machined beryllium-copper parts are bought to: C17200 (and free-machining, lead-bearing C17300) for high-strength springs, bushings, mould inserts and non-sparking tools, C17500/C17510 for resistance-welding electrodes and conductivity-critical parts. Tempers are TB00 (A, solution annealed), TD04 (H, cold drawn), the user-aged TF00 (AT) and TH04 (HT), and mill-hardened tempers. The specification sets composition, dimensional tolerances and the properties required after the standard age — for C17200 a 600 °F (315 °C) age of about 3 h from TB00 or 2 h from TD04, producing tensile strength in the 165–215 ksi (1140–1480 MPa) range with hardness typically in the upper 30s to low 40s HRC — and 900 °F (480 °C) ageing for the conductivity grades. Rod is usually machined in TB00 or TD04 and aged afterwards; the age causes a small, repeatable size change that is allowed for in finish machining.
ASTM B196 types and classes
Every designation the document defines, with the thickness it requires and the tests it imposes.
| Designation | Meaning | Requirement / test |
|---|---|---|
TB00 (A) | Solution annealed; the normal condition for machining, ages to TF00. Available in the full size range. | Tension per ASTM E8 after standard age |
TD04 (H) | Solution annealed and cold drawn; ages to TH04. Limited to diameters that can be cold drawn. | Tension per ASTM E8 after standard age |
TF00 (AT) | TB00 aged about 3 h at 600 °F (315 °C); the common finished condition for machined C17200 parts. | Tension per ASTM E8; hardness per ASTM E18 |
TH04 (HT) | TD04 aged about 2 h at 600 °F (315 °C); the highest-strength rod temper. | Tension per ASTM E8; hardness per ASTM E18 |
Tests and the drawing call-out
Tests the document imposes
- Tension test per ASTM E8/E8M as supplied and after the standard age for heat-treatable tempers
- Rockwell hardness per ASTM E18 (HRB for TB00 / TD04, HRC after age)
- Chemical analysis per ASTM E478 or spectrographic methods
- Electrical resistivity per ASTM B193 for C17500 / C17510
- Dimensional and straightness inspection per ASTM B249 general requirements
How to cite it
Drawing call-out
MATERIAL: C17200 ROD PER ASTM B196, TEMPER TB00 (A); AGE HARDEN TO TF00 AFTER MACHINING, 3 H AT 600 ± 10 °FAngle brackets mark the choices the drawing must make; every finish page shows a completed example.
Heat treatments specified to ASTM B196
| Treatment | Role | Cost |
|---|---|---|
Age C17200 (Beryllium Cu) is a precipitation-hardening condition for C17200 and C17300. | Governing | $$$ |
ASTM B196 — frequently asked
TB00 or TD04 for machined parts?
TB00 (annealed) machines easily and gives TF00 (AT) after the age; TD04 (cold drawn) gives the stronger TH04 (HT) but is available only in the smaller diameters that can be cold drawn. For most machined bushings and inserts TB00 to TF00 is the route; use C17300 when chip control matters on automatic lathes.
How much does the part move during ageing?
Beryllium-copper contracts slightly and repeatably during precipitation hardening; the heat treater can quote the allowance for the alloy and temper. Leave finish stock on tolerances tighter than about ±0.025 mm, or age before final grinding.
Can I skip ageing?
Only if you buy a mill-hardened temper, which is limited in rod sizes, or if the annealed strength (well under half the aged value) is enough. Aged C17200 reaches 165–215 ksi (1140–1480 MPa), more than twice the annealed strength, with far better fatigue and stress-relaxation resistance.
What about the conductivity grades?
C17500 and C17510 (about 0.2–0.6 % Be with cobalt or nickel) age at 900 °F (480 °C) for about 3 h to roughly 100–130 ksi (690–900 MPa) while keeping 45–60 % IACS conductivity, which is why they are used for welding electrodes, mould cores and current-carrying springs.
ASTM B196 is copyrighted by ASTM International. This page explains the document so a drawing can be read; it does not reproduce the standard. Purchase the current edition from the publisher. Official source ↗