摘要 |
A gritless seal, a method for making the seal, and a method for forming a joint with the seal between overlapped ligature segments is provided. The inner gripping layer is brittle and has a hardness greater than that of the outer, ductile layer. In forming the joint, the seal is disposed about the overlapped ligature segments and is folded, squeezed, and/or crimped about the segments under pressure sufficient to deform the outer, ductile layer and produce fracture cracks in the inner gripping layer which present sharp edges to engage and hold the surfaces of the overlapping ligature segments. The interior of the sheet steel seal is case hardened by known cyaniding techniques. |