Materials
Cast Alloys for ANSI Process Pumps: Designation Reference
Casings, impellers and covers are castings, and castings are ordered by cast designation and ASTM specification, not by the name of the wrought alloy they are compared with. This reference lists the cast designations used for ANSI/ASME B73.1 process pump wet ends, the specification that covers each, and the family YSM supplies.
Why the Cast Designation Matters
A casting and a bar or plate of “the same” alloy are made to different specifications with their own composition limits. CF8M is the cast grade usually compared with 316 stainless steel, but it is ordered under a casting specification such as ASTM A743 or A744. A purchase order that says only “316” leaves the casting grade open.
Designation Reference
| Wet-end material | Cast designation | ASTM specification | Usually compared with | YSM supply |
|---|---|---|---|---|
| Carbon steel | WCB | A216 | Carbon steel | Available |
| 316 stainless steel | CF8M | A743 / A744 (A351 for pressure-containing castings) | 316 | Available |
| Duplex stainless steel | CD4MCu | A890 Grade 1A (UNS J93370) | — | Available |
| Alloy 20 | CN7M | A743 / A744 (A351 for pressure-containing castings) | Alloy 20 | Available |
| Nickel-copper | M35-1 | A494 | Monel® 400 | Available |
| Nickel | CZ100 | A494 | Nickel 200 | Available |
| Nickel-molybdenum | N12MV (A494 also covers N7M and N3M) | A494 | Hastelloy® B | Available; grade confirmed at quotation |
| Nickel-molybdenum-chromium | CW6M, CW2M, CW12MW | A494 | Hastelloy® C family (CW2M: C-4; CW12MW: C-276) | Available; grade confirmed at quotation |
| Titanium | C-2, C-3 (B367 lists further grades) | B367 | Available; grade confirmed at quotation | |
| Zirconium | 702C | B752 | On request |
ASTM A890 also covers CD4MCuN as Grade 1B. Designations and specification scopes are taken from the ASTM specifications named above; confirm requirements against the current edition of each specification.
What to State on a Purchase Order
- The part and its position number.
- The cast designation and ASTM specification, and the edition if your company specification requires one.
- Any supplementary requirements your specification calls for.
- The documents you require with the parts, stated at enquiry.
Choosing Between Alloys
This page does not rate corrosion resistance. Use the alloy producers’ published corrosion data and your plant experience, and send the liquid data listed in chemical pump material selection inputs for a reviewed proposal. On the D Mark III series, higher alloys are cast from the same patterns as the CF8M pump, so dimensions and interchangeability do not change with the alloy; the G196 series lists the alloys available for each part.
Cast Alloy FAQ
Is CF8M the same as 316 stainless steel?
CF8M is the cast grade usually compared with 316. It is ordered under a casting specification such as ASTM A743 or A744, with its own composition limits, so a casting is specified as CF8M rather than as 316.
What is CD4MCu?
A cast duplex (austenitic-ferritic) stainless steel, designated ASTM A890 Grade 1A, UNS J93370. The same specification covers CD4MCuN as Grade 1B.
What is CN7M?
The cast grade usually compared with Alloy 20: a 20 chromium, 29 nickel alloy with copper and molybdenum, covered by ASTM A743 and A744.
Which cast grades are used for Hastelloy® B and C type pump parts?
ASTM A494 covers the nickel-molybdenum grade N12MV and the nickel-molybdenum-chromium grades CW6M, CW2M and CW12MW. The grade for a given order is confirmed at quotation.
Send Your Liquid Data
Send the liquid, concentration, temperature and solids data with the installed pump details and we propose a material set for review.
Hastelloy® is a registered trademark of Haynes International, Inc.; Monel® is a registered trademark of Special Metals Corporation. Names are used only to identify alloy families. This is general reference information; final material selection depends on your verified service conditions.