Stair treads

Stair treads - P and SP Stair treads are made according to DIN 24531-1 out of both forge-welded gratings and pressure-locked gratings. Bearing bars 30 x 2 mm, 30 x 3 mm and 40 x 3 mm in size are used for selected stair treads. On the front side of treads there is a welded anti-slip perforated stepping edge which reduces the slip hazard and also increases the static load capacity of the tread and optically emphasizes its front side. Treads are provided with side plates 3 mm in thickness with holes for bolts. The dimensions of treads and pitches of holes in the side plate are shown in the table below.

Prefered sizes of stairtreads:

Lenght L	+0	[mm]	Width B	+5	[mm]	Bearing bar [mm]	b [mm]	c [mm]	d [mm]	e [mm]	Permis. load [kN]	Weight [kg/kus]
	-3			-5
600			240			30x2	55	70	120	85	1,5	4,2
			270				55	70	150	85		4,6
			305				55	70	180	90		5,1
800			240				55	70	120	85		5,3
			270				55	70	150	85		5,9
			305				55	70	180	90		6,5
600			240			30x3	55	70	120	85		5,2
			270				55	70	150	85		5,8
			305				55	70	180	90		6,5
800			240				55	70	120	85		6,6
			270				55	70	150	85		7,5
			305				55	70	180	90		8,3
1000			240				55	70	120	85		8,2
			270				55	70	150	85		9,1
			305				55	70	180	90		10,2
1200			240			40x3	55	70	120	85		11,7
			270				55	70	150	85		13,2
			305				55	70	180	90		14,7

For the fastening of stair treads we supply:

Hexagonal head bolts	M 12 x 35	ISO 4017 (DIN 933)
Hexagonal nuts	M 12	ISO 4032 (DIN 934)
Washers (2 pcs)	M12	ISO 7089 (DIN 125A)

Installation

The stairtreads in accordance to DIN can be produced regarding the length with a minus tolerance and furthermore the stair construction can have tolerances. So it may be necessary to verify before srewing the treads if a washer between cheek and stairtread is needed. Thereby possible damages of the welding of the bearings bars to the side plates can be avoided.