Hollow Core Slab Supports steel parts manufactured by R-Steel R Group Finland Oy under European quality standards. ROK Slab Supports Designed for support of HCS slab end at holes in HCS slab structure. The R-STEEL® ROK is a great technical solution to support hollow-core slabs(HCS) and make openings into hollow-core slab floors. ROK consists of an L-shaped steel front plate welded together with side plates. It transfers HCS slab end support reaction to adjacent HCS slabs or walls in both installations of HCS slabs and in the �nal situation. ROK support (together with seam grout) acts as support structure until fire resistance class R 60 without separate fire protection. Available in several standard models with the maximum width of opening up to 240 cm. RLK and RLKP Slab Supports Steel parts designed for support of precast massive concrete slabs. R-STEEL® RLK and RLKP slab support transfers the slab support reaction to supporting walls or other structures. RLK slab support consists of two square structural hollow section steel tubes that are installed one inside another and ribbed steel bond bars, which are welded to the outer tube. RLKP slab support consists of two square structural hollow section steel tubes that are installed one inside another and studded steel bars, which are welded to the outer tube. Structural hollow section steel tube with the larger section dimensions is installed to the concrete slab before concrete is cast. The end of the steel tube closer to slab edge is pressed against the mold and the other ends is closed with a welded steel plate, which prevents concrete from entering the steel tube during casting. During the installation of the precast slab the smaller tube is inserted in to the larger tube. Smaller tube is left protruding from the slab for approximately 95mm and acts as a cantilever support.