Alloy Steel
Yield Strength MPa (psi) Base Hardness, Rockwell Available Hardness, Rockwell OD Wear Resistance Root Wear Resistance Coorosion Resistance
AISI 4140 689 (100,000) 28-32 Rc 48-55 Rc1 Fair Poor Poor
AISI 4340 758 (110,000) 28-32 Rc 48-55 Rc1 Fair Poor Poor
Nitralloy 135M 586 (85,000) 33 Rc 60-70 Rc2 Good Good Poor

Stainless Steel
Yield Strength MPa (psi) Base Hardness, Rockwell Available Hardness, Rockwell OD Wear Resistance Root Wear Resistance Coorosion Resistance
304 241 (35,000) 80 Rb 90 Rb Poor Poor Good
316 241 (35,000) 95 Rb 90 Rb Poor Poor Good
416 793 (35,000) 30 Rb 30 Rb Poor Poor Fair/Good
17-4PH 1207 (175,000) 38 Rb 42 Rb Poor Fair/Poor Good

Tool Steel
Yield Strength MPa (psi) Base Hardness, Rockwell Available Hardness, Rockwell OD Wear Resistance Root Wear Resistance Coorosion Resistance
D-2 2068 (300,000) 96 Rb 58-60 Rc3 Good Good Poor
CPM 9-V 1965 (285,000) 52-55 Rc 52-54 Rc4 Excellent Excellent Fair
CPM S90V 2241 (325,000) 30 Rc 56-59 Rc4 Good Good Good
H-13 2068 (300,000) 96 Rb 50-60 Rc4 Good Good Fair

Specialty Steel
Yield Strength MPa (psi) Base Hardness, Rockwell Available Hardness, Rockwell OD Wear Resistance Root Wear Resistance Coorosion Resistance
Duranickle 301 862 (125,000) 30-38 Rc 32 Rc Poor Poor Excellent
Hastelloy® C-276 552 (80,000) 86 Rb 86 Rb Poor Poor Excellent

Flite Technology can pretty much made an extrusion screw using just amount any type or grade of steel. The steel can be heat treated, nitrided, plated, coated, hardfaced or encapsulated. We make them out of plastic as well.

Most common are 4140, 4340 HT. 300 and 400 series stainless steel. Others are 17-4 ph stainless, En41B, 38CrMoAlA, SKD11 and SKD61. Tool steels, D-2, H13, Megaware, CPM-9V, CPM-420V. For corrosive applications, Inconel, 713, 718 and 625. Also various grades of Hastelloy and Duranickel.