BS 970 (Part 1):1983 817M40 Steel: Specifications & Listings

Source: BS 970 (Part 1):1983, Table 6

Heat treatment to be given to test bars and to material required in the finally heat treated condition. Note 24: O = oil, W = water. Where oil hardening is specified, either a well-agitated conventional oil or a proven synthetic quenchant may be used. Synthetic quenchants shall not be used for the heat treatment of test bars for material not supplied in the finally heat treated condition. Note 27: tempering between 280 deg C and 500 deg C should be avoided.

Source: BS 970 (Part 1):1983, Table 7

Condition	Limiting ruling section (mm)	Rm (N/mm2)	Re min (N/mm2)	A min (%)	Izod min (ft lbf)	KCV min (J)	Rp0.2 min (N/mm2), when specifically ordered	HB
T	250	850-1000	650	13	30	35	635	248-302
T	150	850-1000	680	13	40	50	665	248-302
U	100	925-1075	755	12	35	42	740	269-331
V	63	1000-1150	850	12	35	42	835	293-352
W (note 11)	29	1075-1225	940	11	30	35	925	311-375
X (note 11)	29	1150-1300	1020	10	25	28	1005	341-401
Y (note 11)	29	1225-1375	1095	10	18	21	1080	363-429
Z (note 11)	29	1550 min	1235	5	8	9	1125	444 min

Values as printed in Table 6 for the limiting ruling section shown. Rp0.2 applies when specifically ordered (note 10). 1 N/mm2 = 1 MPa. Note 11: often ordered in the softened condition for machining and subsequent heat treatment to achieve these specified mechanical properties.

Source: BS 970 (Part 1):1983, Table 6

Condition	Heat treatment condition	Size, diameter or across flats (mm)	Rm (N/mm2)	Re min (N/mm2)	A min (%)	Izod min (ft lbf)	KCV min (J)	Rp0.2 min (N/mm2), when specifically ordered	HB
Hardened and tempered + turned or ground	T	over 150 to 250	850-1000	650	13	30	35	635	248-302
Hardened and tempered + turned or ground	T	over 63 to 150	850-1000	680	13	40	50	665	248-302
Hardened and tempered + turned or ground	U	over 29 to 100	925-1075	755	12	35	42	740	269-331
Hardened and tempered + turned or ground	V	over 13 to 63	1000-1150	850	12	35	42	835	293-352
Hardened and tempered + turned or ground	W (note 11)	6 to 29	1075-1225	940	11	30	35	925	311-375
Hardened and tempered + turned or ground	X (note 11)	6 to 29	1150-1300	1020	10	25	28	1005	341-401
Hardened and tempered + turned or ground	Z (note 11)	6 to 29	1550 min	1235	5	8	9	1125	444 min
Hardened and tempered + cold drawn or hardened and tempered + cold drawn + ground	T	over 63 to 150	850-1000	700	9	40	-	680	248-302 (note 4)
Hardened and tempered + cold drawn or hardened and tempered + cold drawn + ground	U	over 29 to 100	925-1075	770	9	35	-	755	269-331 (note 4)
Hardened and tempered + cold drawn or hardened and tempered + cold drawn + ground	V	over 13 to 63	1000-1150	865	9	35	-	850	293-352 (note 4)
Hardened and tempered + cold drawn or hardened and tempered + cold drawn + ground	W (note 11)	6 to 29	1075-1225 (note 12)	955	8	30	-	940	311-375 (note 4)
Hardened and tempered + cold drawn or hardened and tempered + cold drawn + ground	X (note 11)	6 to 29	1150-1300 (note 12)	1035	7	25	-	1020	341-401 (note 4)
Hardened and tempered + cold drawn or hardened and tempered + cold drawn + ground	Z (note 11)	6 to 29	1550 min (note 12)	1250	3	8	-	1235	444 min (note 4)
Turned, ground or cold drawn and finally softened	-	-	-	-	-	-	-	-	277 max

Size is the diameter or across flats. For cold drawn bar of 6 mm or less, all mechanical properties are subject to agreement between purchaser and supplier at the time of enquiry and order (note 8). For normalizing and hardening and tempering treatments see Tables 3 and 7 (note 9). Rp0.2 applies when specifically ordered (note 10). 1 N/mm2 = 1 MPa. Hardness values marked note 4 are for guidance only. Note 11: often ordered in the softened condition for machining and subsequent heat treatment to achieve these specified mechanical properties. Note 12: cold drawn bars are not normally available in this tensile strength range.

Source: BS 970 (Part 1):1983, Table 4 (bright bar)

Appendix D note 47: where a comparison is made the steels are not necessarily equivalent. 'Not listed' means the earlier edition has no entry under this designation.

Source: BS 970 (Part 1):1983, Appendix D