Abstract: A pipe joint is described for driving pipes laid underground by the driving technique and having an inner pipe made of cast iron to which the force of pressure is applied during driving, wherein each driving pipe is constructed from the inner cast iron pipe formed without a socket and a coaxially disposed outer casing forming a lost casing for an intermediate layer of cement-containing material between the inner and outer pipes. The pipe joint has at least one seal ring disposed on a protruding portion of the inner cast iron pipe.

Abstract: In an apparatus for producing, by the casting technique, a cooling means for narrow webs between adjacent cylinders in a cylinder block, separate cores are provided which are fitted at both ends into a water jacket core or into the bottom core in order to form cooling water channels in the webs. The cylinder blocks produced by the apparatus have in their web areas cooling water channels which are connected with the water jacket.

Abstract: A slow fade cast iron inocculant is made up of(a) a silicon-containing matrix of iron silicon alloys and having a crystal structure,(b) compounds, present in the matrix crystal structure, of high-melting point calcium aluminum silicates, generally in the form CaO.Al.sub.2 O.sub.3.2SiO.sub.2 +Al.sub.2 O.sub.3.2SiO.sub.2, and(c) a dicalcium aluminum silicate material with up to 20% by weight of silicon carbide and 10% by weight of calcium carbide.The relation between the matrix and the high-melting point calcium aluminum silicates to the dicalcium silicate material is about 1 to 0.05-0.2. The amount of high-melting point calcium aluminum silicates in the matrix is 5 to 30% by weight and, more specially 8 to 15% by weight.