817M40/SAE4340 forged steel shaft for mechnical purpose, OD:
4340 is a 1.8% nickel - chromium - molybdenum high hardenability
high tensile steel - generally supplied hardened and tempered in
the tensile range of 930 - 1080 Mpa (condition U) - (Rc 28 - 36).
Characterised by high strength and toughness in relatively large
Pre hardened and tempered 4340 can be further surface hardened by
flame or induction hardening and by nitriding.
4340 is used in most industry sectors for applications requiring
higher tensile/yield strength than 4140 can provide.
Australia AS 1444-2007 4340
Great Britain BS970 1955 EN24
BS970 Part 3:1991 817M40
BS EN10083:1-1991 817M40
USA ASTM A29A29M 1991 4340
ASTM A322 4340
Japan JIS G 4103 SNCM439
JIS G 4103 SNCM8
Werkstoff 1.6565 40NiCrMo6
Phosphorus 0.04 max
Sulphur 0.04 max
Process: EAF+LF+VD+ Forged+Heat Treatment(optional)
Hot Forgedf: 80mm-1200mm
Black, Peeled K12, Cold Drawn, Turned & Polished H10, H11,
Precision Ground H9, H8
Test: Ultrasonic test according to SEP 1921-84 3
Heat to 1150 oC - 1200 oC maximum, hold until temperature is
uniform throughout the section.
Do not forge below 850 oC.
Following forging operation the work piece should be cooled as
slowly as possible in sand or dry lime etc.
4340 in the hardened and tempered as supplied condition is still
regarded as being readily machinable and operations such as turning
and drilling etc. can be carried out satisfactorily using machine
manufacturers, recommendations for suitable tool type - feeds and