Forge-welded gratings SP

The production of forge-welded gratings was started by Lichtgitter in 1966. The production technology has undergone long-term development, with the main emphasis placed primarily on quality, productivity, satisfying the market with a sufficiently wide range of types, and perfect service. This policy has brought Lichtgitter to the absolute top in the field of floor grating manufacturing.

The load-bearing structure of the grating consists of steel flat bars, whose mutual position and stability are ensured by cross bars. The cross bars are made of drawn twisted wire. In addition to ensuring the position and stability of the bearing bars, the cross bars serve to partially redistribute the load to bearing bars outside the loaded area. This fact is also taken into account in the static calculation for grating dimensioning.

The cross bars are welded into the non-weakened bearing bars by applying a current of up to 2500 kVA and simultaneously exerting pressure of up to 1000 kN. Thanks to high-quality fusion at the contact points, the resulting “mesh” structure has both high strength and the ability to favourably redistribute the load. The gratings are edged in the transverse direction by a process in which the edging strip with a double groove is welded at two points along the entire length to each bearing bar. Edging is carried out on an automatic welding unit, which guarantees the highest weld quality. The corners are additionally secured by a spot weld. Only for atypical sizes and shaped gratings are the edging strips welded manually.

Steel S235 JR (according to EN 10025-2: 2020)

The manufacturing technology of forge-welded gratings determines the maximum grating width of 1000 mm. This is the width of an infinitely long strip coming out of the production line, which is then cut into the required dimensions (bearing lengths). The value of 1000 mm is the nominal dimension of the mat. Due to material shrinkage after welding (approx. 2-3 mm), the actual grating width is 997 to 998 mm.

A width other than 1000 mm, as a whole multiple of the centre spacing of the bearing bars, i.e. e.g.: 34.33 mm + 1x the thickness of the bearing bar (dimension “to full mesh”) – see table. Does not require additional edging in the bearing direction!

Bearing bar th.=2mm	38, 72, 107, 141, 175, 210, 244, 278, 313, 347, 381, 416, 450, 484, 519, 553, 587, 622, 656, 690, 725, 759, 793, 828, 862, 896, 931, 965, 1000 (standard width)
Bearing bar th.=3mm	39, 73, 108, 142, 176, 211, 245, 279, 314, 348, 382, 417, 451, 485, 520, 554, 588, 623, 657, 691, 726, 760, 794, 829, 863, 897, 932, 966, 1000 (standard width)
Bearing bar th.=5mm	41, 75, 109, 143, 178, 213, 247, 281, 316, 350, 384, 419, 453, 487, 522, 556, 590, 625, 659, 693, 728, 762, 796, 831, 865, 899, 934, 968, 1001 (standard width)

The stated dimensions are nominal, subject to manufacturing tolerances according to RAL GZ 638. The difference between the nominal and actual dimension is the installation clearance; if we work with the nominal dimension, there is no need to add any additional clearance.

A width that does not correspond to the production dimension; additional edging in the longitudinal direction must be carried out!

6100×1000 mm

In the standard design of the forge-welded grating (according to DIN 24537-1), the centre spacing of the bearing bars is 34.33 mm and of the cross bars 38.1 or 50.8 mm. These types meet the requirement of the ČSN EN ISO 14122 standard regarding the prevention of a D=35mm ball falling through. The clear opening size after deducting the thickness of both elements is approx. 31 x 32 or 31 x 45 mm. Upon customer request, gratings can be supplied with the following mesh sizes: 

Mesh type	Bearing bar spacing	Cross bar spacing
Standard mesh	34,33	38,10
Meshes meeting the standard for the passage of a ball with a diameter of 15* and 20** mm	15,56* 21,64** 34,33	76,20 76,20 24,00**
Other manufactured mesh sizes	30,16 34,33 34,33 34,33 41,46	101,60 50,80 76,20 101,60 101,60

Other mesh sizes upon request.

height	bearing bar thickness
	2 mm	3 mm	4 mm	5 mm
20	upon request	standard production	–	–
25	standard production	standard production	–	standard production
30	standard production	standard production	–	standard production
40	standard production	standard production	standard production	standard production

Other heights and thicknesses of bearing bars manufactured within the Lichtgiter Group are available upon request (up to 80×5 mm).

Forge-welded grating – SP	SP
Bearing bar 30×3 mm		330
Bearing bar spacing 34.33 mm				34
Cross bar spacing 38.1 mm						38
Edging bar 30×3 mm								3
Designation :	SP	330	–	34	/	38	–	3