ISO 898-1: Carbon Steel and Alloy Steel – Bolts, screws and studs

Chemical composition as per ISO 898-1 for typical grades

CLASS	MATERIAL AND TREATMENT	C MIN	C MAX	P MAX	S MAX	B MAX	TEMPERING TEMP. [C]
8.8	CARBON STEEL WITH ADDITIVES (E.G. B, MN OR CR) QUENCHED AND TEMPERED	0.15 (D)	0.40	0.025	0.025	0.003	425
8.8	CARBON STEEL QUENCHED AND TEMPERED	0.25	0.55	0.035	0.025	0.003	425
10.9	CARBON STEEL WITH ADDITIVES (E.G. B, MN OR CR) QUENCHED AND TEMPERED	0.15 (D)	0.35	0.025	0.025	0.003	340
	CARBON STEEL QUENCHED AND TEMPERED	0.25	0.55	0.025	0.025	0.003	425
	CARBON STEEL WITH ADDITIVES (E.G. B, MN OR CR) QUENCHED AND TEMPERED	0.20 (D)	0.55	0.025	0.025
	ALLOY STEEL QUENCHED AND TEMPERED (G)	0.20	0.55	0.025	0.025
12.9	ALLOY STEEL QUENCHED AND TEMPERED (G)	0.28	0.50	0.025	0.025	0.003	380
(D) IN CASE OF PLAIN CARBON BORON STEEL WITH A CARBON CONTENT BELOW 0.25% (LADLE ANALYSIS), MIN MANGANESE 0.6% FOR 8.8 AND 0.7% FOR 10.9
(G) ALLOY STEEL SHALL CONTAIN ONE OF THE FOLLOWING ELEMENTS: CHROMIUM 0.30%, NICKEL 0.30%, MOLYBDENUM 0.20%, VANADIUM 0.10%

Mechanical and physical properties as per ISO 898-1 for typical grades

MECHANICAL OR PHYSICAL PROPERTY		CLASS 8.8 (M16 AND BELOW)	CLASS 8.8 (ABOVE M16)	CLASS 10.9	CLASS 12.9
TENSILE STRENGTH [MPA]	NOM.	800		1000	1200
TENSILE STRENGTH [MPA]	MIN.	800	830	1040	1220
STRESS AT 0.2% NON-PROPORTIONAL ELONGATION (YIELD) [MPA]	NOM.	640		900	1080
STRESS AT 0.2% NON-PROPORTIONAL ELONGATION (YIELD) [MPA]	MIN.	640	660	940	1100
STRESS UNDER PROOF LOAD [MPA]	NOM.	580	600	830	970
ELONGATION AFTER FRACTURE FOR MACHINED TEST PIECE [%]	MIN.	12	12	10	8
REDUCTION OF AREA AFTER FRACTURE FOR MACHINED TEST PIECE [%]	MIN.	52		48	44
IMPACT STRENGTH, CHARPY V-NOTCH [J]	MIN.	27	27	27	(UNDER INVESTIGATION)

Bolts, Screws and Studs (Carbon And Alloy Steel)

Hardness requirement as per ISO 898-1 for typical grades

HARDNESS SCALE		CLASS 8.8 M16 AND BELOW	CLASS 8.8 ABOVE M16	CLASS 10.9	CLASS 12.9
VICKERS, HV	MIN.	250	255	320	385
VICKERS, HV	MAX.	320	335	380	435
BRINELL, HB	MIN.	238	242	304	366
BRINELL, HB	MAX.	304	318	361	414
ROCKWELL, HRC	MIN.	22	23	32	39
ROCKWELL, HRC	MAX.	32	34	39	44

ISO 898-1: Mechanical properties of fasteners made of carbon steel and alloy steel — Part 1: Bolts, screws and studs with specified property classes — Coarse thread and fine pitch thread

Please refer also to: Suitability test requirements (BS EN 15048) – CE Marking