5pcs step drill set, HSS material

Model Number: GMA029 Brand Name: GOLDMOON Key Specifications/Special Features: 5pcs step drill bit set, HSS materialPacking: wooden boxSurface treatment: white finish or titanium coatedSize:4 - 12mm x 9 step 4 - 20mm x 9 step5 - 28mm x 7 step 4 - 30mm x 14 step4 - 39mm x 13 stepDifferent material are available according to customers' requirements. Material Component(%) HSS 4241 C(0.9~1.0);Si(1.0~1.3);Mn(0.25~0.4);P(0~0.035);S(0~0.009);
Cr(3.8~4.2);Mo(0.55~0.85);W(1.6~2.0);V(0.4~0.65);Co(0) HSS 4341 C(0.83~0.93);Si(0.2~0.4);Mn(0.2~0.4);P(0~0.03);S(0~0.009);
Cr(3.8~4.4);Mo(2.5~3.5);W(3.5~4.5);V(1.2~1.8);Co(0) HSS 6542(M2) C(0.8~0.9);Si(0.2~0.45);Mn(0.15~0.4);P(0~0.03);S(0~0.009);
Cr(3.8~4.4);Mo(4.6~4.9);W(5.6~5.9);V(1.8~2.0);Co(0) HSS 9341 C(0.77~0.87);Si(0.2~0.4);Mn(0.2~0.4);P(0~0.03);S(0~0.009);
Cr(3.8~4.4);Mo(2.7~3.3);W(8.5~9.5);V(1.3~1.7);Co(0) HSS M35 C(0.8~0.9);Si(0.2~0.45);Mn(0.15~0.4);P(0~0.03);S(0~0.009);
Cr(3.8~4.4);Mo(4.6~4.9);W(5.6~5.9);V(1.8~2.0);Co(4.6~4.9)