Threaded nuts are made of high quality, durable and rustproof zinc alloy. Unique external thread allows easy insertion of the hole and saves effort. External thread provides strong resistance against pulling out Flanged head prevents surfaces from splitting and drives the insert too deep. Provides a strong permanent thread for wood and wood-based sheet materials. Specifications: Model: M4 Quantity: 50 pieces Color: as shown in pictures Material: zinc alloy Length: 0.8 cm/0.31in Hexagonal width: 0.4 cm/0.16in Weight: approx. 44 g Packaging included: 50 x hex head nut Note: Please allow 1-3mm error due to manual measurement. Thank you for your understanding.