Thomas & Betts 142SL Sealing Locknut Brand: Thomas & Betts. Part Number: 142SL. T&B Sealing Locknut, 3/4 in, For Use With: Rigid/IMC Conduits, Steel, Blue, Zinc Plated, 1.42 in H x 0.28125 in THK. Additional Description: TB -142SL 3/4 INCH LOCKNUT,SEALING. Catalog Description: 3/4 Inch Steel Sealing Locknut for Use With Rigid/IMC Conduit..