Quality Specifications

Quality Specifications Material Specification

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
  • 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.

•  

• 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.
  • ⓐ Elongation - Greater elongation provides increased workability.
  • ⓑ Yield Point - A lower yield point gives better shape to the end product.
  • ⓒ Yield Ratio (yield point/tensile strength) - A lower yield ratio indicates widened differentiation between tensile strength and yield point. Greater difference translates into better work ability.
  • ⓓ Modulus of Elasticity - The modulus of elasticity is in an inverse relationship with resistance to elastic strain. Lowered resistance indicates a better formed product.
  • ⓔ n-Value (Modulus of Work Hardening) - This measure is yielded when the stress- strain curve approximates ∂=CE". Workability is proportionate to the n-value.
  • ⓕ 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 draw ability.

  

  • 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.

  

  Classification of Products

  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.

 

 

Measurement Range

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

 

Comparison of Standards

Chemical Components

Chemical Components

Standard Specification		Applications	Chemical Component
			C	Si	Mn	P	S
KS D 3512 (JIS G 3141)	SPCC	CQ	≤ 0.15	-	≤ 0.60	≤ 0.1	≤ 0.05
	SPCD	DQ	≤ 0.12	-	≤ 0.50	≤ 0.04	≤ 0.04
	SPCE(N)	DDQ(Non-Aging)	≤ 0.10	-	≤ 0.45	≤ 0.30	≤ 0.03
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

Standard Packing

Sheet Weight Table

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	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	7.70	26.5	12
* 0.0138	0.35	0.5636	2.748	10.1	4.59	12.1	5.50	18	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	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	7.22	19.1	8.64	28.4	12.8	44.3	20.1
* 0.0236	0.60	0.9638	4.710	7.3	7.88	20.7	9.42	30.8	14	48.2	21.9
* 0.0276	0.70	1.127	5.495	20.3	9.19	24.2	11	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	11.8	31.1	14.1	46.3	21	72.3	32.8
* 0.0394	1.00	1.609	7.850	29	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	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	96.4	43.8
0.0512	1.30	2.091	10.20	37.6	17.1	45	20.4	66.9	30.3	105	47.4
* 0.0551	1.40	2.250	10.99	40.5	18.4	48.4	22	72	32.7	113	51
* 0.0591	1.50	2.414	11.78	43.5	19.7	51.9	23.6	77.2	35	121	54.7
* 0.0630	1.60	2.573	12.56	46.3	21	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	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	40.8	134	60.7	209	94.8
0.1102	2.80	4.501	21.98	81	36.8	96.8	44	144	65.3	225	102
* 0.1181	3.00	4.823	23.55	86.8	39.4	104	47.1	154	70	241	109
* 0.1260	3.20	5.146	25.12	92.6	42	111	50.2	165	74.7	257	117

Note : * These sizes are applicable to Korea industrial standards.

 

Width-Weight Curves for coil

 

 

Hardness Test Comparison

the 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

Comparison of Gauges

the 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

Conversion Factors