| Aluminum Bronze |
C95200, C95500 |
Higher strength and corrosion resistance than other bronzes and copper alloys. Resistant to seawater corrosion. Non-sparking. |
Vulnerable to impingement attack by abrasive substances (cavitation erosion), filtration sometimes necessary in high speed pumps |
Fair |
Good |
Great in seawater applications and many acids. Resistant to stress corrosion cracking and fatigue. |
| Anti-Galling |
WM88, WM23Bi, WM126, WM54C |
High resistance to galling in metal to metal contact where lubricants cannot be used. Common in the food industry for pump parts, especially rotors in contact with stainless steels. Usable with many chemicals, cleaners, and acidic foods. |
Generally non-weldable, other than nitronic 60. Only usable up to 500F other than WM54C. |
Moderate, comparable to 304 stainless steel |
Non-weldable |
Good, depends on the alloy |
| Austempered Ductile Iron |
ADI Gr 2 and 3 |
High strength and abrasion resistant, competitive with steel, and less dense. Common in automotive, agriculture, construction, and mining. |
Unique heat treatment is required that can cause machining issues. Some shapes difficult to cast. Non-weldable. |
Fair to low |
Non-weldable |
Low |
| Austenitic Stainless Steel |
CF8 (304), CF8M (316) |
Useable at a wide range of temperatures, non magnetic |
Non-hardenable by heat treatment, susceptible to stress corrosion cracking |
Moderate |
Very good, post-weld heat treatment sometimes required to restore corrosion resistance (unless using an ELC grade) |
Good in most environments depending on the grade. |
| Carbon and Low Alloy Steels |
8620, 4130, WCB, C5, C12 |
Wide range of mechanical properties for an economic price. Adaptable to many requirements through different grades and heat treatments. |
Susceptible to corrosion |
Fair to good |
Fair to good |
Low |
| Carbon-Manganese Steel |
LCC, WCC |
Ability to handle high shock loading such as those seen in railroad applications |
Susceptible to corrosion |
Fair to low |
Fair to good |
Low |
| Cast Iron |
Ductile and Gray |
Gray iron has good wear resistance, ductile iron can be comparable to some steels, both are very economic in cost. |
Both are non-weldable. Gray is brittle. |
Good |
Fair, precaution must be taken in filler metal and technique |
Low |
| Cast Iron (White) |
HC250 |
Good wear resistance (or high hardness) and some corrosion resistance. Used in applications that do not require impact strength. |
Very crack prone and non-weldable. Brittle and low impact strength. |
Fair, usually machined in the softened or annealed state |
Non-weldable |
Fair |
| Chromium Nickel Alloy |
50 Cr-50 Ni-Cb (50 / 50) |
Highly corrosion resistant at high temperatures. Mainly used in petrochemical furnaces. |
Susceptible to cold shut or misrun in the casting process, difficult to weld and straighten |
Fair to low |
Low |
Excellent |
| Controlled Thermal Expansion Alloys |
Invar, Kovar |
Mainly used as tooling for composites in aerospace. Almost no dimensional changes over normal atmospheric temperatures, low coefficient of thermal expansion between crogenic temperatures and 500F (high dimensional stability). |
Susceptible to cold shut or misrun in the casting process |
Good |
Good |
Fair |
| Corrosion Resistant Copper Alloy |
WM3, Cupronickel |
Resistant to seawater corrosion, commonly used in desalination applications. High ductility. |
Susceptible to corrosion in the presence of sulfides or ammonia |
Fair |
Non-weldable |
Great in seawater applications and many acids. Resistant to stress corrosion cracking and crevice corrosion. |
| Duplex Stainless Steel |
CD4MCuN |
High strength (~2x austenitic), resistant to erosion and corrosion (better than austenitic), lower nickel and molybdenum content than austenitic without sacrificing corrosion resistance. Less material is generally needed using this alloy for the same performance as austenitic stainless. |
Low impact toughness at low temperatures. Decreased performance at higher temperatures. |
Good |
Good to moderate. Post-weld heat treatment required. |
Great |
| Ferritic Stainless Steel |
CB-30 |
Resistant to stress corrosion cracking (chlorides). |
Not as formable or weldable as austenitic stainless. Decreased performance at lower temperatures. |
Fair to low |
Fair |
Good in environments with chlorides |
| Heat Resistant Stainless Steels |
HK40, HT |
High strength and corrosion resistance at temperatures above 1200F. Resistant to thermal fatigue and shock that comes from repeated temperature change. Mainly used in petrochemical furnaces and oil refineries. |
Cannot be hardened |
Fair |
Moderate. Some grades prone to HAZ cracking. |
Excellent in a wide range of temperatures |
| Manganese Bronze (High Str Yellow Brass) |
C86300, C86500 |
High strength, wear resistance, and corrosion resistance. |
Low machinability |
Fair |
Moderate |
Excellent |
| Manganese Steel |
ASTM A128 |
High impact strength and resistance to abrasion when hardened, easily work hardened. Commonly used in mining and construction. |
Difficult to machine and weld |
Low, even after softening. Work hardens rapidly under cutting and grinding tools. |
Fair, heat must be kept low to avoid cracking |
Fair |
| Martensitic Stainless Steels |
CA15 (410), 420, 440 |
Hardenable by heat treatment. Good corrosion resistance, good impact resistance, capable of elevated temperature strength. Commonly used in pumps and valves, turbines, and propellers. |
Sometimes brittle depending on heat treatment |
Moderate to good |
Moderate, requires post-weld stress relief |
Good in mildly corrosive environments; good erosion resistance, good resistance to cavitation |
| Monel |
M30H, W Monel |
Higher strength than pure nickel, highly corrosion resistant. Commonly used in aggressive seawater applications. |
Non-weldable |
Fair, work hardens quickly, slow feeds and speeds required |
Non-weldable |
Excellent, resistant to most acids and highly corrosive media. |
| Nickel |
CZ100 |
Resistant to strong caustic solutions |
Difficult to weld, sometimes non-weldable |
Fair |
Low, prone to gas |
Good, resistant to strong caustic solutions |
| Nickel Superalloy |
Inconel, Waspaloy, Hastelloy |
Usable at very high temperatures for strength and corrosion resistance. Used in gas turibines and aerospace and nuclear markets. |
Sometimes difficult to weld |
Moderate |
Moderate to fair, depends on the grade |
Excellent even at high temperatures and extremely corrosive environments |
| Ni-Resist (Ductile) |
D-2, D-5B |
Good combination of ductility, corrosion resistance, and wear resistance. Depending on the grade, can perform well at higher temperatures. |
Sometimes difficult to weld |
Moderate |
Fair to moderate |
Moderate, mildly corrosive environments and sea water but not as good as stainless steels |
| Ni-Resist (Gray) |
Type 2, Type 3 |
Good combination of corrosion resistance and wear resistance. |
Brittle, Sometimes difficult to weld |
Good |
Fair |
Moderate, mildly corrosive environments and sea water but not as good as stainless steels |
| Precipitation Hardened Stainless Steel |
CB7Cu-1 (17-4), CB7Cu-2 (15-5) |
High-strength, toughness and weldability. Excellent resistance to stress corrosion cracking (chlorides). High resistance to sulfuric and nitric acids. Used in pump and valve components where hot corrosives or vapors are used. |
Complex heat treatment, difficult to machine after hardening |
Good after annealing and before hardening |
Must be welded in the softened condition, then re-heat treated and aged |
Good |
| Silicon Brass |
C87500 |
High strength and good corrosion resistance. |
Cannot be hardened |
Moderate |
Fair |
Good |
| Silicon Bronze |
C87610 |
Good strength and corrosion resistance. Excellent bearing properties. |
Crack prone |
Moderate |
Fair |
Good |
| Super Austenitic Stainless Steel |
CN7M (Alloy20), CN3MN (AL6XN) |
Resistant to crevice and pitting corrosion (chlorides) and stress corrosion cracking |
Embrittlement at higher temperatures. Prone to segregation and cracking in the casting process, sometimes higher costs |
Fair |
Fair |
Very good, better than normal austenitic stainless steels |
| Tin Bronze |
C90300, C90500, C90700 |
High hardness and strength with good ductility. Good wear resistance and corrosion resistance, commonly used in seawater and brines. |
Tin addition makes this more expensive than lead or bismuth alloys |
Moderate |
Fair |
Good, used in seawater applications |
| Tool Steel |
D2, A2, H13 |
Extremely high hardness and strength, especially compressive and impact strength. |
Non-weldable |
Moderate in the annealed state before hardening |
Non-weldable |
Low |