All AB Grąžtai drills and end mills are made of HSS and HSSCo high-speed steels with a working hardness of 63–67 HRC. Our laboratory tests samples from every steel delivery to confirm that it meets our specifications. Hardening and tempering temperatures and cycles are controlled and recorded so that every tool reaches the required hardness and toughness.
| Grade | AISI | Material No. | C | Si | Mn | Co | Cr | Mo | V | W |
|---|---|---|---|---|---|---|---|---|---|---|
| HSS | M2 | 1.3343 | 0.84–0.92 | ≤0.45 | ≤0.40 | – | 3.8–4.5 | 4.7–5.2 | 1.7–2.0 | 6.0–6.7 |
| HSSCo5 | M35 | 1.3243 | 0.88–0.96 | ≤0.45 | ≤0.40 | 4.5–5.0 | 3.8–4.5 | 4.7–5.2 | 1.7–2.0 | 6.0–6.7 |
| HSSCo8 | M42 | 1.3247 | 1.05–1.12 | 0.20–0.35 | 0.20–0.50 | 7.5–8.5 | 3.6–4.4 | 9.0–10.0 | 1.0–1.3 | 1.2–1.8 |
Chemical composition in % by weight.