Factory Direct Spring Screws, Retaining Rivet Screws, Hand-Tightened Bolts, Panel Fasteners PF31/32-M3-16. Shenzhen Hengbo Precision Hardware Products Co., Ltd. specializes in the production and sales of American PEM and Southco standard rivet screws and various products. A large inventory of commonly used parts is available. Welcome new and old customers to send us your drawings for custom manufacturing. We look forward to establishing a good, mutually beneficial business partnership. Please send us your drawings or call for consultation. Phone: 0755-29941867