Run a Nickel 200 pipe hot enough for long enough and carbon in the alloy starts forming graphite at the grain boundaries, embrittling it right when a hot caustic system needs it least. Nickel 201 fixes it. Same alloy, same 99.0% minimum nickel content, but carbon capped at 0.02% instead of 0.15%, low enough that there's nothing left to form graphite in the first place. USA Piping Solution supplies it as seamless pipe and tube to ASTM B161 and welded pipe to ASTM B725, all in UNS N02201. For service below 600°F, our Nickel 200 Pipes & Tubes page is the more common, lower-cost choice.
High-Temperature Applications
- Hot Caustic Evaporators & Piping: caustic soda service above roughly 600°F, where graphitization resistance is required.
- High-Temperature Chemical Processing: equipment operating in the elevated-temperature range where Nickel 200 is not recommended.
- Electronic & Vacuum Tube Components: parts where low carbon content also supports clean out-gassing.
When to Step Up to Nickel 201
Nickel 200 covers the large majority of commercially pure nickel piping needs. Step up to Nickel 201 specifically when service runs hot: above roughly 600°F (315°C), Nickel 200's carbon content can form graphite at grain boundaries and embrittle the material over time. Below that temperature, Nickel 200 is the more common and more economical choice.
Not Sure Which Grade Fits Your Service? Send Us Your Spec →
Testing, Certification & Availability
Every order ships with mill test certification and full material traceability; see our Quality Policy page for the full testing program we run across all grades. Send us your OD, wall thickness or schedule, and length requirement and we'll confirm current availability and lead time.
Related Products
- Nickel 201 Pipes & Tubes
- Nickel Alloy Pipes & Tubes
- Monel 400 Pipes & Tubes
- Exotic Alloy Pipes & Tubes
Frequently Asked Questions
At what temperature should I switch from Nickel 200 to Nickel 201?
Carbon content. Nickel 200 allows up to 0.15% carbon; Nickel 201 caps it at 0.02%. The lower carbon in 201 prevents graphite forming at grain boundaries above roughly 600°F, which is why it's the elevated-temperature choice.
Does the lower carbon in Nickel 201 reduce its strength?
Slightly. Tensile strength drops from 380 MPa to 345 MPa and yield from 100 MPa to 80 MPa. In elevated-temperature service, avoiding graphitization matters more than the small strength difference.
Is Nickel 201 suitable for vacuum or electronic tube applications?
Yes. Its low carbon content supports clean out-gassing behavior, which is part of why it's specified for electronic and vacuum-tube components in addition to high-temperature process piping.
What sizes are available in Nickel 201 pipe and tube?
We supply from 1/8" NB to 48" NB across Schedule 5 to Schedule XXS. Send us your requirement and we'll confirm current availability.