EOS StainlessSteel GP1 is stainless steel. Its chemical composition corresponds to US classification 17-4, European 1.4542 and German X5CrNiCuNb16-4. Steel including alloying elements like Cr (15 – 17.5 wt-%) Ni (3 – 5 wt-%) Cu (3 – 5 wt-%) Mn (max. 1 wt-%) Si (max. 1 wt-%) Mo (max. 0.5 wt-%) Nb (0.15 – 0.45 wt-%) C (max. 0.07 wt-%)

EOS StainlessSteel GP1 is pre-alloyed stainless steel in fine powder form. Its composition corresponds to US classification 17-4 and European 1.4542. This kind of steel is characterized by having good corrosion resistance and mechanical properties, especially excellent ductility in laser processed state, and is widely used in a variety of engineering applications.This material is ideal for many part-building applications (DirectPart) such as functional metal prototypes, small series products, individualised products or spare parts.

Typical applications:
– engineering applications including functional prototypes, small series products, individualised products or spare parts.
– parts requiring high corrosion resistance, sterilisability, etc.
– parts requiring particularly high toughness and ductility

General process and geometric data
Minimum recommended layer thickness 20 µm
0.8 mil
Typical achievable part accuracy

– small parts

– large parts

± 20 – 50 µm
0.8 – 2.0 mil± 0.2 %
Min. wall thickness 0.3 – 0.4 mm
0.012 – 0.016 in
Surface roughness

– after shot-peening

– after polishing

Ra 2.5 – 4.5 µm, Ry 15 – 40 µm
Ra 0.1 – 0.2 , Ry 0.6 – 1.6 milRz up to < 0.5 µm
(can be very finely polished)
Volume rate

– standard parameters (20 µm layers, full density

– Inner core parameters (Skin & Core style, full density)

2 mm³/s
0.44 in³/h4 mm³/s
0.88 – 1.1 in³/h
Physical and chemical properties of parts
Material composition steel including alloying elements
Cr (15 – 17.5 wt-%)
Ni (3 – 5 wt-%)
Cu (3 – 5 wt-%)
Mn (max. 1 wt-%)
Si (max. 1 wt-%)
Mo (max. 0.5 wt-%)
Nb (0.15 – 0.45 wt-%)
C (max. 0.07 wt-%)
Relative density with standard parameters approx. 100 %
Density with standard parameters 7.8 g/cm³
0.28 lb/in³