API Class SM coupling 1ú¬Type: SM FS and SH coupling 2ú¬Coupling diameter: 5/8 ",3/4",7/8",1",1-1/8" 3)Weight: 0.41-1.29 KG/Pcs 4ú¬Material: AISI 5I40 5ú¬Spray Materialú¦Ni60A Alloy Coating 6ú¬SM Thicknessú¦0.01-0.02in 7) Basic Hardness: HRC 16-23 8ú¬Surface Hardness: HRC 55-62 9ú¬Hole rate: ú+2% 10ú¬Min. Hardness of the layer: 595HV0.2 11) Operating Temperature: -1000~400íµ 12) Life: > 180 days 13ú¬Standard: API Spec 11B 14)Package: wooden case 15)Payment Terms: T/T . Our New Products 1) SM Coupling with great bevel edge 2) Two-way Cambered Protection Coupling.