Product Definition:
Steel grating is a kind of open steel member which the bearing bars & cross bars are jointed at their intersections by welding or locking.
The continuous welding of each individual intesection point of the bearing bar and cross bar produces an extremely stable and hard-wearing structure. The cross bar normally used in the press press welded grating are twisted square wires, which are resistance welded to the bearing bars. This is carried out under high pressure using automatic resistance welding.
Hot DIP galvanized steel grating has four kinds of steel gratings, Flat(or Plain) Style Steel Grating, Serrated Style Steel Grating, I Bar Type Steel Grating and Serrated I Shaped Steel Grating. They are widely used in steel structure platforms, stair treads, sidewalks, drainages and well covers etc. We can design and manufacture standard steel grating and in customized shapes per client's requirements.
Flat : the top surface of bearing bar is flat, which is the most extensively used in all kinds of application.
Serrated: standard grating has square-edge load bars, but where a higher slip resistance may required, serrated load bars should be considered.
I shaped bar: lighter, more economical and practical compared to flat one, improved strength while less in weight
Serrated I Shaped bar: optional, combined both advantages of lighter weight and anti-slip
1) Bearing Bar (Load Bar) Specifications (mm):
The specification of plain type and serrated type bearing bar is 20 x 3 to 100 x 10; The specification of I-section type is 25 x 5 x 3, 32 x 5 x 3, 38 x 5 x 3, 40 x 5 x 3, 50 x 5 x 3, 50 x 7 x 4, 55 x 7 x 4, 60 x 7 x 4, 65 x 7 x 4, 70 x 7 x 4, 75 x 7 x 4, etc.
2) Bearing Bar Pitch (center to center):
12.5, 15, 25, 30, 30.16, 32.5, 34, 40, 41.25, 45, 50, 60, 60.32, 80, 100 mm etc, also be according to client's requirement and 30, 40, 60mm are recommended,
America standard is available <1'' x 3/16'', 1 1/4'' x 3/16'', 1-1/2'' x 3/16'', 1'' x 1/4'', 1-1/4'' x 1/4'', 1 1/2'' x 1/4''(19-w-4) and so on. >
3) Cross Bar Pitch (center to center):
38.1, 40, 50, 60, 76, 80, 90, 100, 101.6, 102, 135mm and so on
4) Material:
Mild Steel (Low Carbon Steel) or Stainless Steel
5) Surface Treatment:
Untreated, Painting or Hot DIP Galvanizing
6) Steel grating standards:
A) China: YB/T4001-1998
B) USA: ANSI/NAAMM (MBG531-88)
C) UK: BS4592-1987
D) Australia: AS1657-1985
E) Japan: JJS.
| Nr. |
Item |
Detailed Description |
| 1 |
Bearing Bar |
25x3, 25x4, 25x4.5, 25x5, 30x3, 30x4, 30x4.5, 30x5, 32x5, 40x5, 50x5, 65x5, 75x6, 75x10---100x10mm etc; I bar: 25x5x3, 30x5x3, 32x5x3, 40x5x3 etc |
| US standard: 1' ' x3/16' ' , 1 1/4' ' x3/16' ' , 1 1/2' ' x3/16' ' , 1' ' x1/4' ' , 1 1/4' ' x1/4' ' , 1 1/2' ' x1/4' ' , 1' ' x1/8' ' , 1 1/4' ' x1/8' ' , 1 1/2' ' x1/8' ' etc |
| 2 |
Bearing Bar Pitch |
12.5, 15, 20, 25, 30, 30.16, 30.3, 32.5, 34.3, 35, 38.1, 40, 41.25, 60, 80mm etc |
| US standard: 19-w-4, 15-w-4, 11-w-4, 19-w-2, 15-w-2 etc |
| 3 |
Twisted Cross Bar Pitch |
38.1, 40 50, 60, 76, 80, 100, 101.6, 120mm, 2' ' & 4' ' etc |
| 4 |
Steel Grade |
ASTM A36, A1011, A569, Q235, S235JR, S275JR, SS304, Mild steel & Low carbon steel, etc |
| 5 |
Surface Treatment |
Black, self colour, hot dip galvanized, painted, spray coating |
| 6 |
Grating Style |
Plain / Smooth, Serrated /teeth, I bar, serrated I bar |
| 7 |
Grating Standard |
China: YB/T 4001.1-2007, USA: ANSI/NAAMM(MBG531-88), |
| UK: BS4592-1987, Australia: AS1657-1985, Japan: JIS |
| I-Bar Name |
H |
T |
t |
Theoretical Weight |
Resistance moment(W) |
Moment of inertia(J) |
| (mm) |
(mm) |
(mm) |
(kg/m) |
cm³ |
cm² |
| I-25×5×3 |
25 |
5 |
3 |
0.75 |
0.48 |
0.6 |
| I-32×5×3 |
32 |
5 |
3 |
0.97 |
0.78 |
1.25 |
| I-38×5×3 |
38 |
5 |
3 |
1.13 |
1.1 |
2.08 |
| I-44×5×3 |
44 |
5 |
3 |
1.3 |
1.46 |
3.22 |
| I-50×5×3 |
50 |
5 |
3 |
1.51 |
1.84 |
4.61 |
| I-50×7×4 |
50 |
7 |
4 |
1.98 |
2.57 |
6.43 |
| I-55×7×4 |
55 |
7 |
4 |
2.18 |
3.09 |
8.49 |
| I-60×7×4 |
60 |
7 |
4 |
2.39 |
3.72 |
11.22 |
| I-65×7×4 |
65 |
7 |
4 |
2.55 |
4.29 |
13.96 |
| I-75×7×4 |
75 |
7 |
4 |
2.96 |
5.7 |
21.39 |
Production Processing:
Standards
The products come from our factory comply to international standards:
| Country |
Bar Grating Standard |
Steel |
Hot-dip Galvanizing |
| P.R.China |
YB/T 4001.1-2019 |
GB/T700-2006 |
GB/T13912-2002 |
| U.S.America |
ANSI NAAMM MBG 531-00 |
ASTM (A36) |
ASTM A123 |
| U.K.British |
BS 4592-1987 |
BS4360(43A) |
BS729 |
| Australia |
AS 1657-1985 |
AS3697 |
AS 1650 |
| Europe |
EN 1090 |
EN 10025:1993 |
EN ISO 1461-1999 |
Tolerance
| (w) |
Toler. of Panel Width |
w max = ±5mm |
| (l) |
Toler. of Panel Length |
L≤2000mm 1 max = ±5mm |
| L>2000mm 1 max = ±3‰*L |
| (d) |
Toler. of Panel diagonals |
L≤2000mm d max = D1 - D2 = ±6mm |
| L>2000mm d max = D1 - D2 = ±3‰*L |
| (b) |
Toler. of B.Bar Spacing |
10 Spacing b max = ±6mm |
| 1 Spacing b max = ±1.5mm |
| (bb) |
Tolerance of bow of bearing bars |
bb max = 1/200*L |
| (c) |
Toler. of C.Bar Spacing |
15 Spacing c max = ±6mm |
| 1 Spacing c max = ±2mm |
| (cb) |
Toler. of curing of cross bars |
cc max = 4‰*W |
| (k) |
Toler. of C.Bar beside B. Bar |
k max = 2mm |
| (q) |
Toler. of C.Bar Upon B.Bar |
q max = 1mm |
| (n) |
Toler. of Banding Bar upon of beneath Bearing Bar |
n/m max = 1.5mm |
| (m) |
| (g) |
Toler. of Lean of B. Bar |
g max = 0.1*H |
| (e) |
Toler. of Longitudinal Staightness |
e1 max = 1/150*L |
| e2 max = 1/200*L |
| (p) |
Toler. of Transverse straightness |
p max = 1/100*W |
How to choose the most suitable one ?
The most extensively used grating series are 20mm,30mm and 40mm bearing bar spacing.These series can satisfy to variant needs by the grating using circumstance.According to bearing bar shape, steel grating falls into four categories: Flat Bar Grating,Serrated Bar Grating,I-Bar Grating and Serrated I-Bar Grating.
To choose a proper type of grating, the bearing bar spacting series should be decided first according to the circumstance where grating is installed. For example, in a public area,20mm series should be chosen to avoid small object falling through; In most industry plants, 30mm series can satisfy almost all platform safety standards world wide; And if the platform is used only occasionally or gratings used to be fencing or elevation elements, 40mm series is an ecnonmical choice.
Then according to the maximum span of grating panels, using the corresponding Loading Table, the most economical bearing bar profile can be selected. SDG recommend the I-bar gratings, for its good loading capacity and less cost performance comparing to 3mm and 5mm thick bearing bars gratings.
Certification
We've been ISO9001 accredited since 2001!
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