Shock-resisting steels are a class of tool steels designed to resist breakage by shock. Under the AISI classification system there are seven types, labeled S1 to S7.
Overview
Shock-resisting steels are designed to have high impact resistance (toughness), along with other properties such as strength, hardness. Silicon is a common addition to this class of steels, as it provides tempering resistance and increases toughness.[1]
Applications for shock-resisting steels includes springs, as well as chisels, dies for forging, and punches.[1] S2 steel is also used to make ball bearings for the mining industry.[2] They are also used for screwdrivers and driver bits.[3]
| Type | C % | Si % | V % | Cr % | Mn % | Ni % | Mo % | W % |
|---|---|---|---|---|---|---|---|---|
| S1 (UNS T41901)[1][3][a] | 0.40–0.55 | 0.15–1.20 | 0.15–0.30 | 1.00–1.80 | 0.10–0.40 | <0.30 | <0.50 | 1.50–3.00 |
| S2 (UNS T41902)[1][3] | 0.40–0.55 | 0.90–1.20 | <0.50 | — | 0.30–0.50 | <0.30 | 0.30–0.60 | — |
| S3[4] | 0.50 | 2.00 | — | 0.74 | — | — | — | 1.00 |
| S4 (UNS T41904)[1] | ? ~0.4–0.65 | 1.75–2.25 | 0.35 | 0.35 | 0.60–0.90 | — | ||
| S5 (UNS T41905)[1][3] | 0.50–0.65 | 1.75–2.25 | <0.35 | <0.50 | 0.60–1.00 | — | 0.20–1.35 | — |
| S6 (UNS T41906)[3] | 0.40–0.50 | 2.00–2.50 | 0.20–0.40 | 1.20–1.50 | 1.20–1.50 | — | 0.30–0.50 | — |
| S7 (UNS T41907)[1][3] | 0.45–0.55 | 0.20–1.00 | 0.20–0.30[b] | 3.00–3.50 | 0.20–0.90 | — | 1.30–1.80 | — |
SVCM
SVCM steel is a kind of shock-resisting steel.[5] SVCM steel is an alloy of carbon, silicon, chromium, magnesium, nickel, molybdenum and lead.[6] SVCM+ in addition is quenched and tempered achieving a high hardness (HRC 59).[6] SCVM+ has better torsional properties than chromium-vanadium steel (Cr-V).[7]