BS EN ISO 4957:2018 · Table 8 and notes a–f. Select for cold-work, hot-work or high-speed tool-steel applications. Intended use and product form require confirmation in the technical agreement.
Cast analysis, mass fraction %. Unspecified values are not zero.
Element
Mass fraction / %
C
0.87～0.95
Si
≤0.45
Cr
3.8～4.5
V
1.7～2.1
Mn
≤0.4
P
≤0.03
S
≤0.03
Mo
4.7～5.2
W
5.9～6.7
Co
4.5～5
Agreed composition conditions and alternatives (not applied automatically)
Default S≤.030%, Mn≤.40%
Element
Mass fraction / %
C
0.87～0.95
Si
≤0.45
Cr
3.8～4.5
V
1.7～2.1
Mn
≤0.4
P
≤0.03
S
≤0.03
Mo
4.7～5.2
W
5.9～6.7
Co
4.5～5
Agreed S .060–.150%, Mn≤.80%
Element
Mass fraction / %
C
0.87～0.95
Si
≤0.45
Cr
3.8～4.5
V
1.7～2.1
Mn
≤0.8
P
≤0.03
S
0.06～0.15
Mo
4.7～5.2
W
5.9～6.7
Co
4.5～5
Properties and applicable conditions
Property
Standard requirements and applicable conditions
Annealed hardness HBW / maximum
269
Hardening test
Austenitizing 1210±10 °C ; oil or salt bath; oil quenching in case of dispute ; minimum tempering temperature 560±10 °C ; hardness≥64 HRC; testing in accordance with B.3.
Standard reference and ordering limitations
Cast analysis, mass fraction %. A dash means the standard gives no separate requirement; it does not mean zero.
Unlisted elements shall not be intentionally added without purchaser consent, except additions needed to finish steelmaking.
Permissible product-analysis deviations do not expand the default cast-analysis limits.
Tool-steel classification and hardness depend on application, heat treatment and test conditions; they do not establish cold-heading suitability or guarantee properties in an arbitrary condition.
Table 8: high-speed tool steels; cast analysis, wt%; default Mn≤.40%, P and S each ≤.030%.
Unlisted elements shall not be intentionally added without purchaser consent, except to finish steelmaking. Dashes are not entered as zero.
Note f: When S .060–.150% is agreed for HS6-5-2-5, Mn≤.80%. Both limits must change together.
Annealed and cold-drawn (+A+C) hardness may be 50 HBW higher than annealed (+A); annealed and cold-rolled (+A+CR) may be 70 HBW higher. Only HS6-5-2C and HS6-5-2-5 may use S 0.060%–0.150% with Mn≤0.80% by agreement under Table 8 note f. This exception does not apply to other grades.
Reference: BS EN ISO 4957:2018，Table 8 and notes a–f. Website information does not replace the official standard, order specifications or material certificates.
Illustrative packaging
Computer-controlled machine packaging · Illustration; packaging is subject to order confirmation.
Product and packaging images are illustrations; they do not identify a heat, stock availability, dimensions or a default delivery method. Confirm product form, delivery condition, packaging and acceptance requirements in the enquiry and order.
TECHNICAL NOTE
Application and ordering note
Chemical composition, mechanical properties, delivery condition and other technical requirements are subject to the currently applicable standard edition, customer drawings and the order technical agreement. Website information does not replace formal quality certification documents.
RFQ CHECKLIST
What to include in the enquiry
Grade and applicable standard
Diameter or section, delivery condition and quantity
Part drawing, forming stations or failure photos, if available
