Key parameters and characteristics of expanded metal sheets
Expanded metal sheet (EMS) is a metal sheet in which holes of a set form are made by simultaneous cutting-out and rolling-out. This manufacturing method provides optimum proportion of product weight and strength.When an expanded metal sheet is manufactured, it is rolled through rollers in order to give it a certain form. The surface of this sheet becomes smooth, but its design properties become worse, that is why for decorative purposes material with insignificant degree of flattening is most appropriate.
For manufacture of expanded metal sheet low carbon steel, stainless steel, galvanized steel as well as aluminum alloy, brass is used.
At present expanded metal sheets are widely used in construction. Examples of its use may be as follows: making staircases and fences, construction of decorative fences, metal city and park furniture, interior elements - ceiling and wall panels, decorative structures, etc. Expanded metal sheets are visually light and strong, which provides this material with enormous architectural potential.
1. The key characteristics and sizes of expanded metal sheets must correspond to the sizes indicated in Tables 1, 2, 3 and 4.
The values of deflections caused by the loads in the above-indicated tables do not exceed the maximum bending of 0.01 from the value of flight (width of expanded metal sheet) in accordance with the Federal Technical Specifications ТУ RRG-661B (the USA) and recommendations providing comfort to pedestrians.
2. Parameters of expanded metal sheets are provided in Appendix 2. Deviations of actual sizes from those stated in Tables 1,2,3 and 4 must not exceed: advancement “Б” + 15%, cell step “В” + 2.0%, sheet thickness “S” + 2.5 mm and rolling-out “А” +4.5 mm.
3. Length of expanded metal sheets manufactured cannot be less than 1.0 m. The length of sheets is set when an order is made within the limits approved by a consumer.
4. Limit deviations from the sizes of sheets must not exceed:
- By width + 10 mm;
- By length + 25 mm per each meter of a sheet length.
5. The cut angle of expanded metal sheets shall not exceed 5 mm per 1 meter of edge.
6. The sheets must have no stress cracks which are longer than 2 mm as well as burrs and notches which are bigger than 2 mm.
7. Unless specially indicated in an order, there may be an uncut-out area which is up to 250 mm long in full width of a sheet at one of a sheet’s ends.
8. Unevenness of sheets’ longitudinal edges must not exceed 2 mm per 1 meter of edge length.
9. Expanded metal sheets must be manufactured by cutting rolled steel into separate work parts which are as wide as a required sheet (b). Cells must be located along rolled steel fiber (diagram 1) and when sheets are used for manufacture of fences and containers, cells can be arranged both along and across rolled steel fiber direction.
Diagram 1
Bл - width of rolled steel in supply condition which is equal to the length of expanded metal sheet work part;
Lл - length of rolled steel in supply condition;
b - width of a work part, which is equal to the width of an expanded metal sheet;
L - length of an expanded metal sheet which is equal to the length of work part В1, multiplied by a rolling-out coefficient К:
Where A – rolling-out size, mm;
l - advancement size, mm.