through the coaction by and between the cable bolt with it enlarged portion as previously described and the elastically expanded material of tubular member 13 such a friction generating bubble travels upwardly relatively speaking in accordance with the downward settling of mine roof strata at this juncture it is important to note that cylindrical members 21 and 22 preferable comprising roll pins will generally be case hardened and approach the surface hardness characteristics of tool steel what is not wanted is any significant plastic deformation of members 21 and 22 rather these should preserve the outward integrity of the strands such that the strands 20 such that the latter are useful to urge outwardly the sidewall of the tubular member 13 to produce the elastic compressive forces as previously mentioned therefore the surface hardness of the members should be not less than 15 percent the surface hardness of the strands 20 the structure in fig2 is similar to that seen in fig1 with the exception that this time in lieu of the inclusions of the cylindrical members 21 and 22 one the king wire a new cylindrical member 35 is employed which is pressed over the cable length in the manner seen in fig2 cylindrical member 35 is preferably case hardened and includes a sidewall slot 36 and also a tapered forward leading edge 37 for ease of installation the cylindrical member 35 gripping the cable length is lightly frictionally seated within counterbore area 17 such that the forward tapered edge or end 37 engages frusto conically formed section 16 of the bore area of tubular member 13 nut 26 is disposed in place as indicated and torqued for desired pre load the settling of mine roof strata.