Technical Comparison: Beryllium vs Beryllium-Free

TECHNICAL COMPARISON: BERYLLIUM VS BERYLLIUM-FREE ALLOYS

RWMA Class 3 (AWS J1.3/J1.3M:2020) - C18000 vs C17510/C17500

Objective: This document presents a technical comparison based on the AWS J1.3/J1.3M:2020 standard between Class 3 beryllium alloys (C17510, C17500) and the beryllium-free alternative C18000 (CuCrNiSi). Both options meet the minimum Class 3 RWMA requirements for resistance welding applications.

CHEMICAL COMPOSITION (AWS J1.3 Table 4)

Alloy	UNS	Beryllium (Be)	Other Elements	RWMA Class
Copper-Chromium-Nickel-Silicon Be-FREE	C18000	0%	Ni 1.8-3.0%, Si 0.4-0.8%, Cr 0.1-0.8%	Class 3
Copper-Nickel-Beryllium WITH Be	C17510	0.2-0.6%	Ni 1.4-2.2%	Class 3
Copper-Cobalt-Beryllium WITH Be	C17500	0.4-0.7%	Co 2.4-2.7%	Class 3

PHYSICAL AND MECHANICAL PROPERTIES (AWS J1.3 Table 5)

Property	AWS J1.3 Class 3 Min	C18000 (Be-Free)	C17510 (CuNiBe)	C17500 (CuCoBe)
Electrical Conductivity	45% IACS min	45% IACS	45-60% IACS	45-48% IACS
Hardness	90 HRB min	90-96 HRB	96-102 HRB	94-100 HRB
Thermal Conductivity	-	~190 W/m-K	208-210 W/m-K	200-205 W/m-K
Softening Temperature	-	~480 C	550 C	540 C
Tensile Strength	-	620-760 MPa	760-900 MPa	720-860 MPa
Density	-	8.75 g/cm3	8.75 g/cm3	8.75 g/cm3

Reference: AWS J1.3/J1.3M:2020 - "Specification for Materials Used in Resistance Welding Electrodes and Tooling" | Table 4: Standard Chemical Compositions | Table 5: Minimum Physical and Mechanical Properties

COMPARATIVE ANALYSIS

C18000 (Beryllium-Free) - Advantages

100% beryllium-free - No OSHA restrictions
No special MSDS required for machining
Complies with strict European regulations
No cost for HEPA extraction systems
Simplified procurement process
Safe for any machine shop

C17510/C17500 (With Beryllium) - Advantages

Higher maximum hardness (up to 102 HRB)
Superior softening temperature (550 C)
Higher tensile strength (up to 900 MPa)
Better thermal conductivity (208-210 W/m-K)
Lower material cost
Greater stock availability

BERYLLIUM SAFETY NOTE: Beryllium alloys in solid bar or plate form are completely safe to handle, transport, and store. Beryllium only poses a potential risk during machining operations that generate airborne dust or fine particles. ALCAVIL complies with OSHA 1910.1024 protocols for safe machining of these alloys.

SELECTION GUIDE

Which alloy to choose?

Select C18000 (Beryllium-Free) when:
- Company has a zero-beryllium corporate policy
- Exporting to markets with strict regulations (EU)
- Machine shop lacks HEPA extraction
- Need to simplify regulatory compliance
- Hardness of 90-96 HRB is sufficient for the application

Select C17510/C17500 (With Beryllium) when:
- Maximum hardness (>96 HRB) or mechanical strength required
- Application demands high softening temperature
- Budget is limited (lower material cost)
- Immediate stock availability needed
- Supplier (ALCAVIL) performs machining under safe protocols

TYPICAL APPLICATIONS - RWMA CLASS 3

Application	C18000 Recommended	C17510/C17500 Recommended
Standard nut projection welding	Yes - Adequate	Yes - Optimal
M10+ nut projection / high load	Marginal	Yes - Recommended
AHSS / DP Steel spot welding	Yes - Adequate	Yes - Optimal
Stainless steel electrodes	Yes - Adequate	Yes - Adequate
Composite electrode inserts	Yes - Adequate	Yes - Optimal
Export to Europe (RoHS/REACH)	Yes - Recommended	Check regulations

CONCLUSION

Both options meet the minimum requirements of RWMA Class 3 per AWS J1.3. C18000 is the choice when safety regulations or corporate policies require zero beryllium. C17510/C17500 offer better mechanical performance at lower cost when OSHA 1910.1024 compliance for machining is guaranteed. ALCAVIL offers both alternatives with precision machining under certified protocols.