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Product Introduction

 

A cold rolled steel sheet is produced by pickling a hot coil and rolling it uniformly at an appropriated temperature to a thinner thickness. It has excellent surface configuration and superb mechanical properties for use in automobile and electronic appliance production.

 

 

Manufacturing availability

 

Quality Specifications

Classification	KSD 3512	JIS G3141	ASTM A1008	EN10130
CQ (Commercial Quality)	SPCC	SPCC	CS	DC01(Fe P01)
DQ (Drawing Quality)	SPCD	SPCD	DS	DC03(Fe P03)
DDQ (Deep Drawing Quality)	SPCE	SPCE	DDS	DC04(Fe P04)
DDQ-N (StabilizedDeep Drawing Quality)	SPCEN	SPCEN	DDS	DC04(Fe P04)
EDDQ			EDDS	DC05(Fe P05)

 

 

Classification of Products

 

• Commercial / Sheet of this quality is for simple bending or moderate forming.  Commercial steel sheet can be bent flat upon itself in any direction at room temperature. It has a wide variety of uses, including automotive panels, electrical home appliances, drums, pipes, farm implements, office supplies, building and civil work materials, and as base metal for various coatings.
• Drawing / Sheet of this quality has a greater degree of ductility and is more consistent in performance than commercial steel because of higher standards in production, selection and melting of the steel. It is suitable for automotive panels, audio-visual equipment, and heating apparatuses.
• Deep Drawing / Sheet of this designation should be used when drawing steel will not provide a sufficient degree of ductility for fabrication of parts with stringent drawing requirements, or applications that require the sheet be free from aging. This quality is produced through special steelmaking and finishing practices. It is suitable for automotive front panels and rear fenders.
• Stabilized Deep Drawing / Stabilized deep drawing quality products boast the highest quality in terms of workability. It is suitable for automotive parts that require complicated treatment such as front fenders or wire. As a non-aging deep drawing sheet made with Al-killed, quality is guaranteed against extreme stretching or straining.
• Surface Finish / The surface finish of cold-rolled steel sheet is either dull or bright.
• Dull Finish / Dull finish, which is attained by attaching numerous fine grains onto the steel surface, is often called 'pear-skin finish' or 'egg-shell texture'. The grains are made by steel grit blasted roll.  The dull finish is useful in drawing because lubricant oil can be evenly spread over the entire surface, thereby reducing the possibility of friction.  The fine grains also help boost paint adherence and extend the steel life span of the steel.
• Bright Finish / Bright finish presents high-quality roughness that is optimal for decorative purposes. The sheet surface is rolled with fine polished rolls.
  

 

 

Edges

Classification	Specifications
Mill Edge	Edges produced by trimming hot rolled coil during the pickling process, prior to cold rolling.
Slit Edge (Trimmed Edge)	Edges produced by shearing or slitting during the cold rolling process.

 

 

Oiling

Sheet that is processed with the final step being the application of oil to the surface; usually intended to provide protection from rusting during shipment and storage. The oil may also serve to assist in the subsequent fabrication process, but this is not usually the main purpose. Dongbu Steel delivers its steel products either oiled (heavy, general or light, dos oiling, powdering) or un-oiled.

 

 

Testing Methods

 

 

Testing Methods
Tensile testing is performed to determine the yield strength, tensile strength, and elongation of steel sheet.

 

• Test Specimen / All types and sizes of test pieces for tension testing are prescribed in the Specifications of KS, JIS, and ASTM. Cold rolled steel sheet, for example, generally uses the specimen collection method indicated in KS B0801. NO.5
• Results / Tension test results are used as a basis for determining the workability and formability of steel sheet.

1. Elongation / Greater elongation provides increased workability.
2. Yield Point / A lower yield point gives better shape to the end product.
3. Yield Ratio (yield point/tensile strength) / A lower yield ratio indicates widened differentiation between tensile strength and yield point. Greater difference translates into better workability.
4. Modulus of Elasticity / The modulus of elasticity is in an inverse relationship with resistance to elastic strain. Lowered resistance indicates a better formed product.
5. n-Value (Modulus of Work Hardening) / This measure is yielded when the stress- strain curve approximates ∂=CE". Workability is proportionate to the n-value.
6. r-Value (Modulus of Plastic Deformation) / Surface shrinkage in the direction of thickness has an inverse relationship with the r-value and the shrinkage in the direction of width is directly proportionate to the r-value. The higher the value, the less susceptible to fracture, hence better drawability.

 

 

Bending Test
The bending test is performed to determine the ductility of steel sheet. The test specimen for cold-rolled steel sheet is designated in KS B 0801 No.3. In the test, the specimen is bent to a specified angle on a mandrel or a specified radius until fracture. The ductility of the sheet is judged by the cracks on the outside of the bent specimen. A cold-rolled sheet specimen is bent 180 degrees.

 

 

 

Hardness Test

Hardness of steel sheet is closely related to other properties like strength, wear resistance, and workability. The hardness test is an easy and effective method of identifying various properties of steel sheet. The Rockwell Hardness test is used for measuring the hardness of cold-rolled steel sheet. The test method is described as follows.

Rockwell Hardness Test
Material resistance to indentation is a qualitative indication of its strength. A steel ball or diamond is often used as an indenter. The hardness value is determined by the difference in penetration depth from the application of an initial minor load onto the indenter followed by a major load. The process is repeated twice. The penetration depth on the surface depends on the increase level in pure load, namely, the B-scale and the F-scale. The B-scale uses a 1/16 (1.588 mm) steel ball indenter and the major load is 100kg. The B-scale most accurately measures specimens with the thickness of 0.762mm (0.030 in.) or over. It is preferable to use the F-scale for specimens with a thickness under 0.762mm.

 

 

 

Workability Test

Tensile strength of cold-rolled steel sheet can be measured in various ways. Since tensile strength is developed through a complicated production process, it is difficult to measure the strength. The two most common ways to measure strength are:

• Erichsen Test - This test measures the drawability of steel sheet. As is shown in the diagram, a test specimen is punched down with a steel ball plunger until the test piece cracks. The h- value, measured when the fracture occurs, is the Erichsen value
• Conical Cup Test - This method has gained popularity in recent years. The specimen is pressed with a flat or round puncher as shown in the diagram. The test value is obtained by measuring the diameter of the cup that the specimen has been drawn into. Because the value closely corresponds to the actual performance of steel sheet fabrication, this test method is widely used by automobile makers.

 

 

 

Measurement Range

 

 

 

Note:
1. Sizes indicated in will be subjected to negotiation.
2. Coil is available with an inside diameter of 508㎜(20in.) or 610㎜(24in.)
3. Coil is available in weight ranging between 2.5 tons (5,500 lbs.) are 20 tons (44,000 lbs.)

 

 

 

Comparison of Standards

 

 

Chemical Components

Standard Specification		Applications	Chemical Component
			C	Si	Mn	P	S
KS D 3512 (JIS G 3141)	SPCC	CQ	≤ 0.12	-	≤ 0.50	≤ 0.040	≤ 0.045
	SPCD	DQ	≤ 0.10	-	≤ 0.45	≤ 0.035	≤ 0.035
	SPCE (N)	DDQ (Non-Aging)	≤ 0.08	-	≤ 0.40	≤ 0.030	≤ 0.030
ASTM A 1008	CS	CQ	≤ 0.10	-	≤ 0.60	≤ 0.030	≤ 0.035
	DS	DQ	≤ 0.08	-	≤ 0.50	≤ 0.020	≤ 0.030
	DDS	DDQ (Non-Aging)	≤ 0.06	-	≤ 0.50	≤ 0.020	≤ 0.025
EN 10130	DC01 (Fe P01)	CQ	≤ 0.12	-	≤ 0.60	≤ 0.045	≤ 0.045
	DC03 (Fe P03)	DQ	≤ 0.10	-	≤ 0.45	≤ 0.035	≤ 0.035
	DC04 (Fe P04)	DDQ (Non-Aging)	≤ 0.08	-	≤ 0.40	≤ 0.030	≤ 0.030
	DC05 (Fe P05)	EDDQ	≤ 0.06	-	≤ 0.35	≤ 0.025	≤ 0.025

 

 

Mechanical Properties

Standard Specification		Application	Mechanical Property
			Y.P	T.S	Elongation Min (%)
			Yielding Point (N/㎟)	Tensile Strength (N/㎟)	0.25≤t ＜0.40	0.40≤t ＜0.60	0.60≤t ＜1.0	1.0≤t ＜1.6	1.6≤t ＜2.5	t≥2.5
KS D 3512 (JIS G 3141)	SPCC	CQ	-	≥270	(32)	(34)	(36)	(37)	(38)	(39)
	SPCD	DQ	-	≥270	34	36	38	39	40	41
	SPCE (N)	DDQ (Non-Aging)	-	≥270	36	38	40	41	42	43
ASTM A 1008	CS	CQ	(140~275)	-	30 (L0 =50mm)
	DS	DQ	(150~240)	-	36 (L0 =50mm)
	DDS	DDQ (Non-Aging)	(115~200)	-	38 (L0 =50mm)
	EDDS	EDDQ	(105~170)	-	40 (L0 =50mm)
EN 10130	DC01 (Fe P01)	CQ	≤ 280	270~410	28 (L0 =80mm)
	DC03 (Fe P03)	DQ	≤ 240	270~410	34 (L0 =80mm)
	DC04 (Fe P04)	DDQ (Non-Aging)	≤ 210	270~410	38 (L0 =80mm)
	DC05 (Fe P05)	EDDQ	≤ 180	270~410	40 (L0 =80mm)

 

Standard Specification	Mechanical Property
	Hardness
	Temper	HRB	Hv
KS D 3512 (JIS G 3141)	1/8H	50~71	95~130
	1/4H	65~80	115~150
	1/2H	74~89	135~185
	H	≥85	≥170

 

 

 

 Standard Packing

 

 

Dongbu Steel’s cold-rolled sheet and coil is packed to withstand handling during transportation and long-distance shipping. Special care is taken to prevent abrasion, rusting and scratching. Our packing procedure is illustrated below. The unit weight per package is usually between 2 and 5 tons for sheet and between 4 and 20 tons for coil.

 

 

Coil Packing

 

Sheet Packing

 

 

 

Sheet Weight Table

 

 

Weight		Weight per Sheet
Classification
Thickness		Width		3ft (914mm)		3.28ft (1,000mm)		4ft (1,219mm)		5ft (1,524mm)
		Length		6ft (1,829mm)		6,56ft (2,000mm)		8ft (2,438mm)		10ft (3,048mm)
		Weight Unit
in.	mm	lb/ft²	kg/㎡	lb	kg	lb	kg	lb	kg	lb	kg
* 0.0079	0.20	0.3226	1.570	5.81	2.63	6.94	3.14	10.3	4.67	16.1	7.29
0.0091	0.23	0.3716	1.806	6.69	3.02	8.00	3.61	11.9	5.37	18.6	8.39
* 0.0098	0.25	0.4002	1.962	7.20	3.28	8.61	3.92	12.8	5.83	20.0	9.11
* 0.0106	0.27	0.4329	2.120	7.79	3.54	9.31	4.24	13.9	6.30	21.6	9.85
* 0.0118	0.30	0.4819	2.355	8.67	3.94	10.4	4.71	15.4	7.00	24.1	10.9
0.0130	0.33	0.5309	2.590	9.56	4.33	11.4	5.18	17.0	7.70	26.5	12.0
* 0.0138	0.35	0.5636	2.748	10.1	4.59	12.1	5.50	18.0	8.17	28.2	12.8
* 0.0157	0.40	0.6412	3.140	11.5	5.25	13.8	6.28	20.5	9.33	32.1	14.6
* 0.0177	0.45	0.7229	3.532	12.0	5.91	15.6	7.06	23.1	10.5	36.1	16.4
* 0.0197	0.50	0.8045	3.925	14.5	6.56	17.3	7.85	25.7	11.7	40.2	18.2
* 0.0217	0.55	0.8862	4.318	16.0	7.22	19.1	8.64	28.4	12.8	44.3	20.1
* 0.0236	0.60	0.9638	4.710	17.3	7.88	20.7	9.42	30.8	14.0	48.2	21.9
* 0.0276	0.70	1.127	5.495	20.3	9.19	24.2	11.0	36.1	16.3	56.4	25.5
* 0.0315	0.80	1.287	6.280	23.2	10.5	27.7	12.6	41.2	18.7	64.4	29.2
* 0.0354	0.90	1.446	7.065	26.0	11.8	31.1	14.1	46.3	21.0	72.3	32.8
* 0.0394	1.00	1.609	7.850	29.0	13.1	34.6	15.7	51.5	23.3	80.5	36.5
0.0433	1.10	1.768	8.635	31.8	14.4	38.0	17.3	56.6	25.7	88.4	40.1
* 0.0472	1.20	1.928	9.420	34.7	15.8	41.5	18.8	61.7	28.0	96.4	43.8
0.0512	1.30	2.091	10.20	37.6	17.1	45.0	20.4	66.9	30.3	105	47.4
* 0.0551	1.40	2.250	10.99	40.5	18.4	48.4	22.0	72.0	32.7	113	51.0
* 0.0591	1.50	2.414	11.78	43.5	19.7	51.9	23.6	77.2	35.0	121	54.7
* 0.0630	1.60	2.573	12.56	46.3	21.0	55.4	25.1	82.3	37.3	129	58.3
* 0.0709	1.80	2.896	14.13	52.1	23.6	62.3	28.3	92.7	42.0	145	65.6
* 0.0787	2.00	3.214	15.70	57.9	26.3	69.2	31.4	103	46.7	161	72.9
* 0.0906	2.30	3.700	18.06	66.6	30.2	79.6	36.1	118	53.7	185	83.9
* 0.1024	2.60	4.182	20.41	75.3	34.1	90.0	40.8	134	60.7	209	94.8
0.1102	2.80	4.501	21.98	81.0	36.8	96.8	44.0	144	65.3	225	102
* 0.1181	3.00	4.823	23.55	86.8	39.4	104	47.1	154	70.0	241	109
* 0.1260	3.20	5.146	25.12	92.6	42.0	111	50.2	165	74.7	257	117

Note: These sizes are applicable to Korea industrial standards.

 

 

 

 

Width-Weight Curves for Coil

 

 

Inside Diameter is 508mm (20 in)
* Coil width is the same as that of the cold-rolled strip.
* The coil lamination factor is assumed to be 100%.

 

 

 

Hardness Test Comparison

 

Rockwell Hardness				Vickers Hardness	Rockwell Hardness				Vickers Hardness
B Scale	F Scale	Superficial			B Scale	F Scale	Superficial
HB	HF	H30T	H15T	Hv	HB	HF	H30T	H15T	Hv
100	113.3	80.8	90.6	235	75	99.3	64.8	82.8	140
99.5	113.0	80.5		232	74.5	99.0	64.4		138
99	112.7	80.1	90.3	229	74	98.7	64.1	82.5	137
98.5	112.4	79.8		227	73.5	98.5	63.8		136
98	112.1	7.5	90.0	224	73	98.2	63.5	82.2	134
97.5	111.9	79.2		221	72.5	97.9	63.2
97	111.6	78.9	89.7	218	72	97.6	62.8	81.9	132
96.5	111.3	78.5		216	71.5	97.3	62.5		131
96	111.0	78.2	89.4	214	71	97.1	62.2	81.6	129
95.5	110.7	77.9		211	70.5	96.8	61.9		128
95	110.5	77.6	89.1	209	70	96.5	61.6	81.3	127
94.5	110.2	77.3		207	69	95.9	60.9	81.0	125
94	109.9	76.9	88.8	205	68	95.4	60.3	80.7	123
93.5	109.6	76.6		202	67	94.8	59.6	80.3	120
93	109.3	76.3	88.5	200	66	94.3	59.0	80.0	119
92.5	109.1	76.0		198	65	93.7	58.4	79.7	117
92	108.8	75.7	88.1	196	64	93.2	57.7	79.4	115
91.5	108.5	75.3		194	63	92.6	57.1	79.1	113
91	108.2	75.0	87.8	192	62	92.0	56.4	78.8	111
90.5	107.9	74.7		190	61	91.5	55.8	78.5	109
90	107.7	74.4	87.5	188	60	90.9	55.2	78.2	107
89.5	107.4	74.1		186	59	90.4	54.5	77.8	106
89	107.1	73.7	87.2	184	58	89.8	53.9	77.5	104
88.5	106.8	73.4		182	57	89.2	53.2	77.2	103
88	106.6	73.1	86.9	180	56	88.7	52.6	76.9	102
87.5	106.3	72.8		178	55	88.1	51.9	76.6	100
87	106.0	72.4	86.6	176	54	87.5	51.3	76.3	99
86.5	105.7	72.1		175	53	87.0	50.7	75.9	98
86	105.4	71.8	86.3	173	52	86.5	50.0	75.7	96
85.5	105.2	71.5		171	51	85.9	49.4	75.4	95
85	104.9	71.2	86.0	170	50	85.3	48.7	75.0	94
84.5	104.6	70.8		168	49	84.8	48.1	74.7	93
84	104.3	70.5	85.6	166	48	84.2	47.5	74.4	92
83.5	104.0	70.2		164	47	83.7	46.8	74.1	91
83	103.8	69.9	85.4	163	46	83.1	46.2	73.8	90
82.5	103.5	69.6		161	45	82.5	45.5	73.5	89
82	103.2	69.2	85.0	160	44	82.0	44.9	73.2	88
81.5	102.9	68.9		158	43	81.4	44.3	72.9	87
81	102.6	68.6	84.7	156	42	80.9	43.6	72.5	86
80.5	102.4	68.3		155	41	80.3	43.0	72.2	85
80	102.1	68.0	84.4	154	40	79.3	42.3	71.9	84
79.5	101.8	67.6		152	39	79.2	41.7	71.6	83
79	101.5	67.3	84.1	150	38	78.6	41.1	71.3	82
78.5	101.2	67.0		149	37	78.1	40.4	71.0	81
78	101.0	66.7	83.7	147	36	77.5	39.8	70.7	80
77.5	100.7	66.4		146	35	77.0	39.1	70.4	80
77	100.4	66.0	83.5	145	34	76.4	38.5	70	80
76.5	100.1	65.7		144	33	75.8	37.9	69.7	78
76	99.9	65.4	83.2	142	32	75.3	37.2	69.4	78
75.5	99.6	65.1		141	31	74.7	36.6	68.1	77

 

 

 

Comparison of Gauges

 

 

Gauge No.	U.S.G.		B.W.G.		B.G.		S.W.G.		M.S.G.		G.S.G.
	mm	in.	mm	in.	mm	in.	mm	in.	mm	in.	mm	in.
10	3.572	0.1406	3.40	0.134	3.175	0.1250	3.251	0.128	3.416	0.1345	3.510	0.1382
11	3.175	0.1250	3.05	0.120	2.827	0.1113	2.946	0.116	3.037	0.1196	3.132	0.1233
12	2.778	0.1094	2.77	0.109	2.517	0.0991	2.64	0.104	2.657	0.1046	2.753	0.1084
13	2.381	0.0938	2.41	0.095	2.240	0.0882	2.34	0.092	2.278	0.0897	2.372	0.0934
14	1.984	0.0781	2.11	0.083	1.994	0.0785	2.03	0.080	1.897	0.0747	1.994	0.0785
15	1.786	0.0703	1.83	0.072	1.775	0.0699	1.83	0.072	1.709	0.0673	1.803	0.0710
16	1.588	0.0625	1.65	0.065	1.588	0.0625	1.63	0.064	1.519	0.0598	1.613	0.0635
17	1.429	0.0563	1.47	0.058	1.412	0.0556	1.42	0.056	1.367	0.0538	1.461	0.0575
18	1.2700	0.0500	1.24	0.049	1.257	0.0495	1.22	0.048	1.214	0.0478	1.311	0.0516
19	1.1113	0.0438	1.07	0.042	1.118	0.0440	1.02	0.040	1.062	0.0418	1.158	0.0456
20	0.9525	0.0375	0.89	0.035	0.996	0.0392	0.91	0.036	0.912	0.0359	1.006	0.0396
21	0.8731	0.0344	0.81	0.032	0.886	0.0349	0.81	0.032	0.836	0.0329	0.930	0.0366
22	0.7938	0.0313	0.71	0.028	0.794	0.0313	0.71	0.028	0.760	0.0299	0.853	0.0336
23	0.7144	0.0281	0.64	0.025	0.707	0.0278	0.61	0.024	0.683	0.0269	0.777	0.0306
24	0.6350	0.0250	0.56	0.022	0.629	0.0248	0.56	0.022	0.607	0.0239	0.701	0.0276
25	0.5556	0.0219	0.51	0.020	0.560	0.0220	0.51	0.020	0.531	0.0209	0.627	0.0247
26	0.4763	0.0188	0.46	0.018	0.498	0.0196	0.46	0.018	0.455	0.0179	0.551	0.0217
27	0.4366	0.0172	0.41	0.016	0.443	0.0175	0.417	0.0164	0.417	0.0164	0.513	0.0202
28	0.3969	0.0156	0.36	0.014	0.397	0.0156	0.376	0.0148	0.378	0.0149	0.475	0.0187
29	0.3572	0.0141	0.33	0.013	0.353	0.0139	0.345	0.0136	0.343	0.0135	0.437	0.0172
30	0.3175	0.0125	0.30	0.012	0.312	0.0123	0.315	0.0124	0.305	0.0120	0.399	0.0157
31	0.2778	0.0109	0.25	0.011	0.279	0.0110	0.295	0.0116	0.267	0.0105	0.361	0.0142
32	0.2580	0.0102	0.23	0.009	0.249	0.0098	0.274	0.0108	0.246	0.0097	0.340	0.0134
33	0.2381	0.0094	0.20	0.008	0.221	0.0087	0.254	0.0100	0.229	0.0090	-	-
34	0.2183	0.0086	0.18	0.007	0.196	0.0077	0.234	0.0092	0.208	0.0082	-	-
35	0.1984	0.0078	0.13	0.005	0.175	0.0069	0.213	0.0084	0.191	0.0075	-	-

 

Note

U.S.G = United States Standard Gauge Wrough Iron 401b/f²-in. B.W.G = Birmingham Wire Gauge B.G = Birmingham Gauge

S.W.G = Standard Wire Gauge M.S.G = Manufacturer's Standard Gauge 40321b/f²-in. G.S.G = Galvanized Sheet Gauge

 

 

Conversion Factors

 

 

Weight

Classification	Kilogram	Ounce	Pound	Short Ton (2,000 lbs)	Long Ton (2,240 lbs)	Metric Ton (1,000 kg)
	kg	oz	lb	st	lt	t
Kilogram (kg)	1	35.2740	2.20462	0.001102	0.0₃9842	0.001
Ounce (oz)	0.02835	1	0.06250	0.0₄3125	0.0₄2790	0.0₄2835
Pound (lb)	0.45359	16	1	0.00050	0.0₃4464	0.0₃4536
Short Ton (st)	907.185	32,000	2,000	1	0.89286	0.90719
Long Ton (lt)	1,016.05	35,840	2,240	1.12	1	1.01605
Metric Ton (t)	1,000	35,274	2,204.62	1.10231	0.98421	1

(Example 0.0₃9842 = 0.0009842)

 

 

Linear Measure

Classification	Millimeter	Centimeter	Meter	Inch	Foot	Yard	Mile
	kg	oz	lb	st	lt	t	mi
Millimeter(mm)	1	0.1	0.001	0.03937	0.0032808	0.0010936	0.06214
Centimeter(cm)	10	1	0.01	0.3937	0.032808	0.010936	0.06214
Meter(m)	1,000	100	1	39.37	3.28083	1.0936	0.06214
Inch(in.)	25.40	2.540	0.0254	1	0.0833	0.02778	0.01578
Foot(ft)	304.8	30.48	0.3048	12	1	0.3333	0.01894
Yard(yd)	914.4	91.44	0.9144	36	3	1	0.05682
Mile(mi)	1,609,347.0	160,934,.70	1,609.35	63,360	5,280	1,760	1