Leaded Bronze Lb1 Flange Rings Specification

Leaded Bronze LB1 Equivalent Designation
| UNS Designation | British STD | Werkstoff No. | European STD | Swedish STD | Japanese STD |
|---|---|---|---|---|---|
| C93100 | Lb1 | – | Cupb15sn | – | – |
Leaded Bronze Lb1 Flange rings are seamless rolled or open-die forged components used as pressure-vessel flanges, valve bodies, hub-mount blanks, and shaft-end retention rings. TorqBolt supplies Leaded Bronze Lb1 Flange rings per ASTM A182 (forged flange standard), ASTM A266/A668 (carbon ring), and EN 10222 (pressure-purpose forging), in OD sizes from 50 mm up to 3000 mm.
Rings are produced via either seamless ring rolling (radial-axial mill, for OD > 200 mm) or open-die hammer forging (for short-run / oversize parts). Reduction ratio ≥ 4:1 from billet to final ring is enforced for grain-flow continuity. Heat treatment is per the alloy spec — solution-anneal + quench + age for precipitation-hardening alloys; quench & temper for low-alloy steels.
Leaded Bronze Lb1 Flange rings are supplied to ASTM A788 dimensional tolerances by default: OD ±1.5 mm or ±1% (whichever is larger), ID ±1.5 mm, height ±0.8 mm. Tighter tolerances (machined finish, ±0.1 mm) available for direct-mount applications. Out-of-roundness controlled to 1.5 mm; concentricity 0.2 mm/100 mm.
Each ring lot ships with full mechanical certification: tensile (ASTM E8), Charpy impact (ASTM E23) at the application's MDMT, hardness traverse, and grain size per ASTM E112. For Leaded Bronze Lb1 Flange ring stock destined for hydrogen / sour service, additional HIC testing (NACE TM0284) and SSC testing (NACE TM0177) per the customer's spec.
Leaded Bronze Lb1 Flange rings ship rough-machined or finish-machined per drawing. Standard NDT: 100 % UT (ASTM A388 reference) and surface MT/PT to ASTM E709 / E165. Radiography on request. Each ring is hard-stamped with heat number, lot, and certification reference for traceability through the dispatch chain.
Bronze alloys are copper-based alloys with tin, aluminium, silicon, manganese, or phosphorus alloying additions, each tuned for a specific tribological or environmental envelope. Bronzes deliver excellent bearing properties, marine corrosion resistance, and non-sparking + non-magnetic characteristics — specified for marine fasteners, electrical hardware, oil + gas wellhead components, and industries where sparks must be avoided.
Phosphor bronze (Cu-Sn-P, e.g. C51000, C52400) combines high yield strength + fatigue with seawater corrosion resistance — the standard for marine + spring fasteners. Silicon bronze (Cu-Si, e.g. C65500) is the marine-grade weldable alloy popular for boat fasteners and architectural cladding. Aluminium bronze (Cu-Al, e.g. C95400/C95500/C95800) achieves yield ~310-585 MPa with outstanding seawater + cavitation resistance — the workhorse for marine pump impellers and propeller hub bolting. Gunmetal (Cu-Sn-Zn-Pb, e.g. C90500) is the historic naval bronze for valves and trim. Leaded bronze adds Pb for free-machining + bearing applications.
Bronze fasteners ship per ASTM B98 (rod/bar) and B584 (sand cast) with EN 10204 3.1 / 3.2 certificates covering composition, hardness, and ASTM B66 ammonia stress-corrosion testing where service exposure warrants.