Api 3/4¡± class sm slim hole sucker rod coupling 1) material: aisi 5140 2) standard: api spec 11b 3) main specification: Od:1-1/2" (38.1mm) Id: 1-1/16"(26.99mm) Length: 4" (101.6mm) Weight: 0.47kg 4)other size: 3/4¡±; 7/8¡±;1¡±; 1-1/8¡± 5)smoothness: 3.1*10-3 6)coat thickness(in): 0.01in ~ 0.02in 7)basic hardness: hrc 16-23 8)surface hardness: hrc 55-62 9)bonding strength(mpa): 484 10)hole rate: 180 days 15) package: wooden case, 1000pcs each case. 16) usage: oil exploration equipment, accessories, oil sucker rod coupling We are the manufacturer of sucker rod couplings and can supply the high quality sucker rod couplings in low price with the hope to establish a long-term relationship with you. If any of the sucker rod couplings interests you, please contact me for more information about the sucker rod couplings. Wooden cases