Quality

King STEELS SPRING STEEL FLAT SIZES

WIDTH	THICKNESS(mm)
50	5	6	6.5	7	8	9	10	11	12	.	.	.	.	.	.	.	.	.	.	.	.
50.8	6.14	7.95	9.12	9.93	10.31	12.7	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.
57	7.5	8	9	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.
57.15	8.33	9.12	10.19	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.
60	6	7	8	9	10	10.3	10.5	11	12	13	14	15	16	17	18	19	20	23	.	.	.
63.5	4.76	6.35	6.65	7	7.94	9	11	12	12.7	.	.	.	.	.	.	.	.	.	.	.	.
70	5	6	7	7.5	8	9	10	11	12	12.7	13	14	17	18	20	22	23	25	26	28	.
75	8	9	11	12	13	20	26	28	.	.	.	.	.	.	.	.	.	.	.	.	.
76.2	8.7	10.31	11.1	11.11	12.67	12.7	13	14	14.28	14.30	15	17	19	21	22.53	26.95	.	.	.	.	.
77	11	12	13	14	15	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.
80	7	9	10	11	12	13	14	15	16	17	18	19	20	22	23	24	25	26	32	.	.
88.9	25.4	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.
90	6	9	9.8	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	28
100	9	10	11	12	12.7	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28
101.6	11.1	12.7	13.39	19.5	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.
104	18	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.
106	21	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.
119	14	18	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.
120	14	16	18	24	25	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.

Above mentioned sizes in chart are sizes we roll regularly, we can also roll any other sizes as per demand of the customer.

Different grades which we offer with chemical composition for spring steel.

Grade	C%	Mn%	Si%	S% (MAX)	P% (MAX)	Cr%	Other%
EN45A	0.58-0.65	0.80-1.00	1.70-2.00	0.035	0.050	0.20 max	–
65SiCr7	0.60-0.80	0.70-1.00	1.50-1.80	0.045	0.045	0.20-0.40	–
65Si7	0.60-0.68	0.7-1.00	1.50-1.80	0.040	0.040	–	–
60Si7	0.55-0.65	0.80-1.00	1.50-2.00	0.045	0.045	–	–
60SiCr7	0.55-0.65	0.70-1.00	1.50-1.80	0.045	0.045	0.20-0.40	–
60SiCr7	0.55-0.65	0.70-1.00	1.50-1.80	0.045	0.045	0.20-0.40	–
SUP 6	0.56-0.64	0.70-1.00	1.50-1.80	0.025	0.025	–	–
SUP 9	0.50-0.60	0.65-0.95	0.15-0.35	0.035	0.035	0.65-0.95	Al: 0.04 max
SUP11A	0.56-0.64	0.70-1.00	0.15-0.35	0.035	0.035	0.70-1.00	B: 0.0005 min, Al: 0.04 max
50CrV4	0.47-0.55	0.70-1.10	0.15-0.40	0.030	0.030	0.90-1.20	V: 0.10 to 0.20, Al: 0.04 max
EN 47 A	0.45-0.55	0.50-0.80	0.50 max	0.050	0.050	0.80-1.20	V: 0.15 min, Al: 0.04 max
51CrV4	0.47-0.55	0.70-1.10	0.15-0.40	0.025	0.025	0.90-1.20	V: 0.10-0.25, Al: 0.04 max

Flat thickness by IS Standard

Flat Thickness (mm)	Full	Partial	Total
< 13	0.05	0.150	0.200
13 – 15	0.05	0.250	0.300
15 – 18	0.05	0.250	0.300
18 – 25	0.05	0.350	0.400
25-30	0.05	0.350	0.400

Mechanical Properties

UTS, MPa	YS, MPa	El%	RA%
1300 – 1700	1170 -1550	7 min	25 min

Tolerance: As Per IS 3431

Width Tolerance

Width Tolerance	Tolerance on Width
OVER 38 UP TO 50	± 0.30
OVER 50 UP TO 75	± 0.50
OVER 75 UP TO 100	± 0.70
OVER 100 UP TO 125	± 0.90

Thikness Tolerance

< = 10 MM	> 10 MM
± 0.15	± 0.15
± 0.15	± 0.20
± 0.20	± 0.25
± 0.25	± 0.40

Edge radius: Thickness / 2 (T/2) mm ± 2 mm as per DIN STD: EN10092-1

Length : As specied in Purchase Order with margin of. 0 to 50 mm per flat

Supply Condition

The flat will be straight, and free from lateral kinks, waves, twists or other surface imperfections such as splits, flakes, pits, heavy scale, rust, cracked edges and other rolling defects.