Monument socket forming tools (copper pipe jointers) are ideal for joining 2 pieces of copper pipe of equal diameter together without using fittings. The loose former allows easier withdrawal of tool after use. The resulting capillary joint that is left can be soft or hard soldered to finish the joint. Available in a variety of sizes 15, 22, 28 and 15 & 22mm. Monument 131W Socket Forming Tool. Size 15mm.